FAO IntroductionIntroduction FORESTRY to ergonom'csergonomics• PAPER in forestryforestry 10010 inn deve'opingdeveloping countries

FOOD AND AGRICULTUREAGRICULTURE ORGANIZATION OF THE UNITED NATIONSNATIONS Ronne,Rome, 19921992 The designations employedemployed andand thethe presentationpresentation ofof materialmaterial inin thisthis publication do not imply thethe expressionexpression of anyany opinionopinion whatsoeverwhatsoever on the part ofof thethe FoodFood andand AgricultureAgriculture OrganizationOrganization ofof thethe UnitedUnited Nations concerning the legal status of any country, territory,territory, citycity oror area or of its authorities,authorities, oror concerningconcerning the delimitationdelimitation of itsits frontiers or boundaries.

M-39 ISBNISBN 92-5-103177-0

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© FAOFAO 19921992 - i i - -

FOREWORD

Ergonomics, whichwhich is thethe studystudy of the efficiency of personspersons in their working environment, has beenbeen relativelyrelatively neglectedneglected so farfar inin developingdeveloping countries.countries. TheThe reasons forfor thisthis low prioritypriority are are many,many, andand relaterelate notnot onlyonly toto the the lack lack of of human human and and financial resources, butbut also, inin the case ofof forest ergonomics, toto the low statusstatus enjoyed by forestry workwork andand thethe generalgeneral belief thatthat training inin this field isis a liability rather than a profitable investment.investment.

This is regrettableregrettable as ergonomicsergonomics isis one ofof thethe essentialessential elementselements inin strategies aimed at reducingreducing thethe costscosts associatedassociated withwith equipmentequipment downtime,downtime, suboptimal processingprocessing capacity, andand the underutilization as wellwell as overexploitationoverexploitation of forestforest resources,resources, andand thethe attendantattendant problems.problems.

Forestry work isis inin generalgeneral physicallyphysically demandingdemanding and, at times,times, dangerous.dangerous. Additionally, high-energyhigh-energy food provision,provision, health,health, medicalmedical andand otherother servicesservices forfor forestry workersworkers areare oftenoften poor.poor. AllAll these,these, andand manymany otherother deficiencies,deficiencies, pointpoint toto the needneed for greatergreater awareness,awareness, training, andand extension in forestforest ergonomics.ergonomics.

This document is aimed at forestry instructorsinstructors andand trainers, particularlyparticularly at technical and vocational level, forfor thethe developmentdevelopment ofof educationeducation andand trainingtraining programmes. ItIt is also meantmeant to stimulatestimulate forestryforestry teachersteachers andand researchersresearchers to study thethe variedvaried workwork environmentsenvironments inin forestryforestry andand hovvhow they affect thethe forestryforestry worker inin terms ofof his/herhis/her safety,safety, health,health, well-beingwell-being andand efficiency.efficiency.

Mechanization, and and thethe steady increase inin the useuse ofof expensiveexpensive andand sophisticated equipment, needneed to bebe paralleledparalleled withwith improvedimproved occupationoccupation safetysafety and health,health, inin order to makemake forestryforestry workwork aa productive andand progressiveprogressive occupation.

J.P..P. LanlyLanly Director Forest Resources Division Forestry Department - ii -

ACKNOWLEDGEMENT

This document isis based onon thethe workwork of Ms.Ms. L.L. BostrandBostrand with inputsinputs byby Messrs. B. Frykman, B. Strehlke, F.F. Standt, E.E. Apud and P. Harstela.Harstela. The drawings are by NilsNils Forshed.Forshed. - iii -

TABLE OF CONTENTS

Page

1.1. INTRODUCTION ...... •...•...... •••...... aoOOOOOOOOOOO.....•. 041.040..... 1

1.1 Introduction to Ergonomics ...... •..•...... 1

1.2 A Model forfor ErgonomicsErgonomics inin ForestryForestry •.•••...... ~ 5

2. THE WORKER AND THE WORK .....••...... •••.•..... 9

2.1 The Human Body ...•...... ••...••...... 9

2.2 Energy Requirements and Physical WorkloadWorkload .•...... 12

2.3 workWork Postures .•.....•..•..•...... •.•...•...... 23

2.4 NutritionNutri tion ••...... •...... 33

2.5 Fatigue ••...... •...... ••••...... 38 38

2.6 Rest Periods and Scheduling of Working Hours .•...... 39

2.7 Mental Workload and Stress ..... 44

2.8 Individual Characteristics ofof thethe WorkerWorker ..•...... 46

2.9 Socio-cultural Aspects ...... 48

3. WORKING ENVIRONMENT ....••...... •...... •...... •..•...... 50

3.1 Biological and PhysicalPhysical FactorsFactors ...... •..... 50

3.1.1 ClimateClimate...... •...... • . • ...... • . . . . 50 3.1.2 TopographyTopography...... •.. .•...... •. .•.. 57 3.1.3 Harmful plants, , animals,animals, snakes,snakes, insects, infections,infections, etc.etc. ..•.••••...... •..... 59

3.2 Technological and Organizational FactorsFactors ...... 69

3.2.1 Design, use and maintenance of tools and machines ••...... •.•....•••...•... 69

3.2.2 NoiseNoise...... amoih0000 71 -- iviv -

3.2.3 Vibration.Vibration . . . . • ...... • ...... • . . • • . . . • • • . . . • . . . 78 3.2.4 Harmful substances, e.g. chemicals,chemicals, solvents,solvents, gases, smoke and dust ...... 83

3.2.5 Ventilation and draughtdraught ...... •...... 90

3.2.6 Lighting...... Lighting...... 92

4. OCCUPATIONAL ACCIDENTS AND DISEASESDISEASES ...... •...•..•.....•••...•.• 94

4.1 AecidentAccident StatisticsStatistics ...... •...... e0 0 0 0 0 000 00 0 96

4.2 Accident InvestigationInvestigation ...... •.•....•.•...... e a ' ...... 98

4.3 Near-Accidents ...... ••.•....••...... 99

4.4 Systems Analysis ...... •.....•...•.•.....•••...... 99

5. MEASURES AT THE NATIONALNATIONAL AND ENTERPRISEENTERPRISE LEVELLEVEL ...... 100

5.1 MeasuresMeasures at the National LevelLevel ...... •.••.., .•••••..... 101

5.2 Measures at thethe Enterprise Level •...•.•...... 109

5.2.1 Technical measures 109

5.2.2 Behavioural approach .....•...... •••.•...... 117

5.2.3 Organizational measures 119

5.2.4 Occupational health and safety organization..organization 119

5.2.5 Occupational health servicesservices .....••...... • 123

5.2.6 First-aid and emergency treatmenttreatment ...... • 127

5.2.7 Workwork studystudy ...... 128

6. ERGONOMIC PROBLEMS IN DIFFERENT FORESTRY ACTIVITIES .•...... 130 6.1 Working andand LivingLiving ConditionsConditions ofof ForestryForestry Workers in GeneGeneral ral ..•....•...... •.•...... 130

6.2 Nursery Work ....••...... •....•.•...... 131

6.3 Planting ActivitiesActi vi ties ...... •••...•..•....••••...... 134

6.4 Logging Operations ...... •..•...•.•••...... 141 --V- v -

6.5 Loading and unloadingUnloading ...... •.....•.... . 155

6.6 Other Activities inin ForestryForestry 158

6.6.1 Forest firefire fightingfighting 158

6.6.2 Timber floatingfloating...... •... .•...... 160

6.7 Wood Processing .•....•.....•.....•.....•.....•...... 160

6.7.1 Accident risksrisks and preventive measures ...... 161

6.7.2 Health risksrisks and preventive measures ...... 166

6.7.3 Other ergonomic factorsfactors ••...... 169

7. THE USE OF ERGONOMIC CHECKLISTS ...... •....•... 169

7.1 Background and Objectives ...... •...... 169

7.2 RequiRequired red Conditions ...... •... 170

7.3 How to use the Checklist ...•...... ••.... 171

7.4 Ergonomic Checklist forfor Workplaces •...... •...... 173

REFERENCES 195

•e •Is

_ -1-- 1 -

1. INTRODUCTIONINTRODUCTION

1.1 Introduction toto ErgonomicsErgonomics

Working andand livingliving conditionsconditions forfor forestforest workers are generally poor in most countriescountries allallover over thethe world; very often,often, work efficiency isis also poor. Physically heavy work, inadequate working methods, working techniques andand toolstools andand equipmentequipment causecause notnot onlyonly occupationaloccupational accidents,accidents, diseases andand unnecessaryunnecessary fatigue,fatigue, butbut lowlow productivityproductivity asas well.well. In countries with available accident records,records, forestryforestry appears toto be one of the most hazardous occupations, with frequentfrequent and severesevere accidents andand many diseases.

The improvementimprovement ofof safety,safety, health,health, well-being andand efficiencyefficiency isis a basic condition forfor prosperity, and ergonomics isis a very importantimportant tooltool for thisthis.

What isis ergonomics?ergonomics? The word ergonomicsergonomics isis ratherrather new.new. ItIt was coinedcoined aboutabout thirtythirty years ago. Today, thethe termterm ergonomics refersrefers toto thethe studystudy of workers inin theirtheir working environment.environment. Essentially, thisthis means fittingfitting thethe jobjob toto thethe workerworker and optimizing thethe man-task-environment systemsystem with due regardregard toto efficiency andand toto thethe worker'sworker's safety,safety, healthhealth andand well-being.well-being. It also means "fitting"fitting thethe worker toto thethe job",job", forfor example,example, by giving proper training forfor thethe jobjob andand providingproviding adequateadequate foodfood andand medicalmedical services.services. Other terms used synonymouslysynonymously includeinclude "human"human engineering" and "human"human factors".factors" .

The fieldfield ofof ergonomicsergonomics isis relativelyrelatively young andand thethe termterm ergonomicsergonomics is still unknown by many. This does not mean, however, thatthat thethe problems' and their solutionssolutions inin thethe fieldfield ofof ergonomicsergonomics areare new.new. Man has always striven toto facilitatefacilitate work.work. In fact, most of today'stOday's sophisticated machines have developed fromfrom yesterday's simplesimple tools.tools.

Very often, inin thethe coursecourse ofof thisthis development due regardregard hashas notnot beenbeen given to the worker's safety,safety, health, well-being andand efficiency. Instead, the machines and power tools used todaytoday are oftenoften designed without givinggiving much consideration toto thethe worker's capacitiescapacities andand limitations.limitations. Therefore, workers continue to put theirtheir safety,safety, health andand well-being at risk,risk, asas illustrated in FigureFigure 1. The alternative to mechanization is often to use the tools of yesterday, which have remainedremained unchanged over thethe years althoughalthough theirtheir design and method ofof useuse maymay notnot bebe optimal.optimal.

One reason for this is that force of habit prevents us fromfrom discovering thethe simplesimple solutionsolution toto a problem,problem, forfor instance,instance, inin termsterms ofof minor changes inin tool design and work method.

Instead of looking atat present tools and methods to see if they can be modified, there isis a tendencytendency toto acceptaccept thingsthings asas theythey are becausebecause "that"that isis howhow they have always been". ~-=~-

- 2 -

Figure 1. Machines andand powerpower toolstools inin use todaytoday exposeexpose workers toto many risks. - 3 -

Elements of ergonomics

Ergonomics consistsconsists ofof twotwo majormajor elements,elements, namely:namely:

1) A technicaltechnical partpart concerningconcerning thethe practicalpractical aspectsaspects of optimizing workplaces, machines, tools, etc., often called "Applied Ergonomics";

2) A human partpart concerningconcerning thethe description and knowledge ofof physical and psychological characteristics of man, e.g. in terms of measures, reactions, needs,needs, capacities andand limitations.

Accordingly, ergonomicsergonomics isis notnot aa singlesingle science,science, butbut thethe applicationapplication of many scientific disciplinesdisciplines suchsuch asas anatomy,anatomy, anthropometry,anthropometry, physiology,physiology, experimental andand behaviouralbehavioural psychology,psychology, occupationaloccupational medicinemedicine andand hygiene,hygiene, pathology, sociology,sociology, learninglearning techniquestechniques andand engineering,engineering, as well asas economics.

In the beginning, ergonomics was defined as all steps and measures taken with the aim of adapting work to thethe individual'sindividual's abilities and limitations. The term "work""work" here was usedused inin itsits broadestbroadest sense.sense. Besides the job task itself, it also includedincluded localities, work postures, and everything else inin thethe working environmentenvironment ofof importanceimportance forfor thethe worker. At aa laterlater stage,stage, thethe definitiondefinition ofof ergonomicsergonomics waswas givengiven anan eveneven broaderbroader coverage. Methods have been designed forfor analyzinganalyzing and improvingimproving thethe whole man-task-environment systemsystem andand thethe interrelationinterrelation betweenbetween different partsparts within thisthis system.system. This is called systems-analysis or systems-ergonomics (see sectionSection 4.4).4.4).

In the application of ergonomics there will also be a need to include the system's interactioninteraction with thethe existingexisting social,social, economiceconomic andand politicalpolitical systems.

To summarize, the main objective of all ergonomic efforts is to fit the work to man's needs, capacitiescapacities andand limitationslimitations byby adjustingadjusting thethe technology and organization of work oror toto adjustadjust man toto thethe job,job, throughthrough proper training, information,information, andand thethe provision ofof adequate food,food, healthhealth services, etc.etc. In evaluating whether or not a jobjob task is acceptable from an ergonomic point of view, certaincertain criteriacriteria havehave toto be met. Examples ofof these criteria include:include:

a. Safety (protection(protection from being injuredinjured inin a work-related accident)accident); ;

b. Health (absence(absence of or protection from work-related diseases);

c. Fatigue and discomfort (physical(physical and mental workload should be adjusted toto factorsfactors suchsuch asas worker's age,age, sex,sex, nutritionalnutritional status and physical fitness);fitness);

d. Security of employment; -4 -

e. Work satisfactionsatisfaction (e.g.(e.g. findingfinding one's work useful or interesting; having opportunities to use and develop existing skills and to learnlearn newnew skillsskills onon thethe job);job);

f. Remuneration, socialsocial securitysecurity andand welfare;

g. Efficiency (quantity(quantity andand qualityquality ofof output).output).

The most importantimportant of thethe above-mentioned criteria are safety, health and fatigue. If the job does not meet the standards forfor thesethese threethree criteria it cannot be regarded as acceptable from an ergonomic point of view. The criterion regardingregarding efficiency should be met only within the limits of these threethree fundamentalfundamental considerations.considerations. Fortunately, efficiency will usually improveimprove when thethe jobjob isis performed inin an ergonomic way, using proper tools and methods. A cost-benefitcost-benefit analysis, taking intointo consideration the whole economy of a country and not limited to the individual enterprise only, will usually show the advantages of the application of ergonomics inin workingworking life.life.

Sometimes the negative effects of forest work on health are indirect and thereforetherefore difficultdifficult toto proveprove inin anan evaluation.evaluation. Occupational diseases such as back disease and impairment of hearing usually take a long time to develop. InIn suchsuch casescases itit isis moremore difficultdifficult toto taketake protectiveprotective measures.measures. The improvement of work efficiency as a result of applying ergonomics is also difficult to demonstrate inin manymany cases.cases. It is not easy to quantify the monetarymonetary benefits if,if, forfor example:example:

the quantity of the work output is still the same, but the worker produces itit with lessless effort,effort, energy and riskrisk involved;

the quality has improvedimproved butbut isis notnot measured;measured;

- absenteeism caused by work-related accidents and diseases has decreased;

- work satisfaction has improvedimproved among the workers, leadingleading toto reduced labour turnover; oror

the image of the enterprise has improved and has led to the recruitment of good workers becomingbecoming easier.easier. Usually, therethere isis aa tendencytendency toto measuremeasure factorsfactors whichwhich areare easyeasy toto measure, and also toto putput more emphasisemphasis onon thingsthings which areare measurable.measurable. This has often led toto other factors,factors, which also havehave aa decisivedecisive impactimpact onon the result,result, being completely overlookedoverlooked or given aa much lowerlower priority. This has been one of the major drawbacks inin thethe promotion ofof ergonomics.ergonomics. - 5 -

1.2 A Model for Ergonomics inin Forestry

The most important goal forfor ergonomics is to adjust the working environment toto thethe worker. The working environment cancan bebe defineddefined asas allall the conditions, circumstances, and influences surrounding and affecting the worker.

The model given inin this publication attempts to provide a structure for some of the most commoncommon andand importantimportant factors.factors. It is straightforward and easy toto understand.understand. Nevertheless, an example will be given to illustrate how itit works.works.

In FigureFiffire 2,2, thethe "Affecting"Affecting factors"factors" areare foundfound onon thethe left.left. The factors inineir t eir different combinationscombinations formform thethe workingworking environment.environment. There is a fundamental difference between factorsfactors which originate from nature itself, suchsuch asas treetree dimensions, terrain or climate, and factorsfactors created by man, suchsuch asas tools,tools, machines,machines, workwork methodsmethods andand organizations.organizations. The factors originating fromfrom nature itselfitself are usually more difficult to control. This is particularly true for forestry activities when the workers have toto workwork outout ofof doors.doors.

Therefore thesethese factorsfactors havehave been put inin a separateseparate box: (1) BiologicalBiolo ical andand physicalh sical factors.factors. The man-made factorsfactors areare putput inin boxbox TechnologicalTec 0 og1ca andan organizationalor an1zat10nal factors.factors. Examples of factors inin each boxbOx are shown inin FigureFigure. 3.1 Some factors may fit inin both boxes (1)(1) andand (2),(2), e.g. animals used for haulagehaUlage form part of thethe method used; insects,insects, bacteria and viruses are often resultsresults of poor sanitarysanitary conditions due to technical or organizationalorganizational shortcomings.shortcomings. In spite of these and other examples, each factorfactor hashas beenbeen putput inin onlyonly oneone box.box.

All thethe factorsfactors inin boxesboxes (1)(1) andand (2)(2) willwill inin oneone wayway oror anotheranother affect the worker. This is indicated by thethe arrow.arrow. There is only one arrow from all thethe factors.factors. It is essential to bear inin mind thatthat itit isis thethe combination of all the factors which make up the working environment. certainCertain factors may be ratherrather harmless when considering the isolatedisolated effect of each one ofof them.them.

When combinedcombined withwith somesome otherother factorsfactors thethe resultresult mightmight bebe hazardous.hazardous. For example, payment on a piece-rate basis couldcould be advantageous inin certain jobs, for both workers andand employer.employer. When thethe systemsystem isis applied toto a dangerous job, which requiresrequires much skill, experience and difficult decisions such as the fellingfelling of big trees with a ,chainsaw, thethe resultresult will often be more accidents andand workerworker fatigue.fatigue.

Another exampleexample isis thatthat exposureexposure toto differentdifferent airair pollutantspollutants atat thethe same time often results in new effects due to the combination of the harmful substances.substances. The total effect could either be the straight sum of the individual effects of the different pollutants (1+1=2),(1+1=2), or itit could be greater than the sumsum (1+1=3).(1+1=3). In the latter case, thethe effects ofof thethe harmful substances strengthenstrengthen eacheach other,other, which isis calledcalled synergism.synergism.

The final effect on thethe worker also depends onon different individualindividual characteristics, such as age, sex, body size and health, justjust toto mention a few. Many harmful chemicalschemicals will, forfor instance,instance, havehave anan eveneven moremore harmfulharmful effect on workers who smoke!smoke! -- 66 - -

Affecting Factors:

(1) BiologicalBiol ogi cal Effects onon the:the : andand physicalphysical factors Individual I character- Worker Production I iisticsst i cs (2) Technological e% I I and 1 1 organizationalorganizationa l I' 1 1 factors 1 1 1 1 1 1 1 1 1- - -' "'------"I Feedback systemsystem Measures atat the:the: 1 1 -i,- V

National Enterprise level level

Figure 2-2· Model forfor Ergonomic ProblemsProblems inin ForestryForestry Work.Work. hunidityhumidity Biological andand rainrain heat physical factors snowsnow cold cold .R Climate /" ~ Flora trees I -I plants Fauna animalsanimals I Individual Harmful Costly -I insectsinsects chara"cteristicschara-cteristics effects effects Microorganisms flq!ifungi onQn the on bacteriabacteria. Age a!t1t\JOealtitude Age worker production virus Sex Topography slq>eslope ~tionalOlcupational terrain Race, size injuries kc.identsAccidents distance Health Diseases Absenteeism Diseases Labour Nutritional status-status Fatigue Labour I • Physical~ical fitness turnover EducationEifu::ation i-<-0 DiscomfortDi=mfort I--t Inefficiency I • Low Experience W. Organizational andand noise motivationrrotivation Poor quality vibration CulturalQjltural backgroundbackgrO\.md W.Low technolo2icaltechnological factors vibration Attitudes Mental stressstress prcxh.x::.tivityproductivity gas Machines Socio--ecorxxnicSocio-econsmic - - smokeSllDke situation - - dust (e.g. family, housing) Tools (e.g. family, housing) chEmicalschemicals EhploymentEmployment condition condition I solvents Equipment (e.g. casual,casual, seasonal,seasonal, I penranent)permanent) 24> ~~~viSibilityilitY I Material ~ lightingli ting - - I Methods ventilation I ver;.;;J.~tiondtadraught t J Techniques design function J ..., OrganizatOrganization ion workload J Management ""~=dworkpace ce J rest periodsperiods J ______J~------,------schedule I supervisionsuPervision Measures at at nationalnational and enterpriseenterprise levelleve I • I 4 Choice of-Exchange of Enclosure or isolation of technologyharmful factors harmful factors, e.g. by National level Enterprise level for safe or less harmful onesusing guards,redesigning Legislation Technical measures personal '7 protective Health & safetysafety inspections Selection and placement Introduction, oirthe-job devices Safety associations of workers training Accident insurance agenciesagenCies Persuasive Social securitysecurity systemssystems Behavioural measures propaganda Rehabilitation institutionsinstitutions Work organization, e.g. job Manufacturers rotation, lob enlargement Testing stations Organizational Dealers Dealers Organizationalmeasures -----II~~~~~~~~;;~~~~~~~;;~~~====.==~~~L---~_.\411 \At Research institutionsinstitutions PlanningPlarming and follow-foUcu- InsoectionsInspections andand I Supervision Remuneration Educational institutionsinstitutions Occupational up of productionproduction enenf"0fceqent orcement of health and safety reguiationsre2\l atl.ons Vocational training health and safety organization Extension services organization '------f------, Preventive, curative Occupational health and rehabilitative services measures First aidaid andand emergency treatment

Figure 33. . The modemodel 1 and some examplesexamples. _ -8 -

The effects on the worker could be of different degrees of seriousness, fromfrom a generalgeneral feelingfeeling ofof discomfortdiscomfort toto fatal.fatal. The effects on the worker will have effects onon production.production. Most of these effects are very difficult toto measure. ItIt isis also difficult toto seesee the linkage between, for example, labour turnover, poor quality or inefficiency and fatigue or mental stress caused by technologicaltechnological or organizational factors.

To draw the conclusion that something which is difficult to measure is unimportant to studystudy would bebe aa bigbig mistake.mistake. On the contrary, it is very importantimportant toto studystudy andand controlcontrol thethe effectseffects ofof poorpoor workingworking conditions.conditions.

The model also has two boxes indicating measures for improvement of the workingworking conditions.conditions. In the box to the left a number of measures toto bebe taken at the national level are listed such as legislation, social security and education. In the boxbOx to the rightright measures toto bebe takentaken atat thethe enter~riseentetTrise level are listed, such as occupational health and safety organlzation,organization, paymentpayment systemsystem andand on-the-jobon-the-job training.training. manyMany of thesethese measures are to be takentaken both at the national and at the enterprise level. Close collaboration between different governmental bodies, associations, educational institutions and the representativesrepresentatives of industry and different enterprises isis necessary.necessary.

In the model in FigureFi~re 2 there is also an arrow markedmarked withwith a broken line from the "worker andan prprOduction"uction" boxes to the "national- and enterprise-level" boxes.boxes. This arrow indicates that there is a possibility to obtain feedbackfeedback fromfrom thethe affectedaffected workersworkers onon thethe workingworking environment.environment.

Most of the working environment isis createdcreated by man, and can therefore also be changed by man.man. The arrow indicates how the workers, either individually or collectively, can have an impact on their own working environment.

In the following sections, almost all of these factors willwill be discussed. Some of the subjects will be only briefly discussed, as there is already a great dealdeal ofof writtenwritten materialmaterial availableavailable onon them.them. It would also take too much space to handle them in a meaningful way. Examples of such subjects are design, use and maintenance of tools and machines, felling techniques, andand first-aid.first-aid.

The chapters are not structuredstructured inin thethe samesame way as the factorsfactors are structured inin the model. It would not make sensesense toto enumerateenumerate allall thethe affecting factors, one after the other, without a simultaneous description of how they affect the worker and the production, and what the preventive measures are.are. For example, "organizational factors" will not be given a chapter on its own, but will be discussed, in a number of chapters whenever applicable, and often asas examples ofof preventivepreventive measures.

The model can also serve as a teachingteaching aid when introducing ergonomics forfor thethe firstfirst timetime toto newnew groups.groups. -9 -

2.2 • THE WORKERWORKER AND THE WORKWORK

2.1. The Human Body

For an understanding of thethe interrelationshipsinterrelationships between man, his work and the environment, it is necessary to have some basic knowledge of anatomy, which is the study of the form and structure of the body, and physiology, which deals with the life processes of the body. In this introduction to ergonomics some aspects of these subjects will be discussed very briefly, mainly those dealing with the skeleton, joints,joints, muscles, and blood circulation and respiratoryrespiratory systems.systems.

A. The skeleton

About 17% ofof thethe humanhuman bodybody isis made up ofof thethe skeleton,skeleton, which consists of somesome 200200 bones.bones. Of the many different partsparts ofof thethe skeleton, it is particularly the spinal column which is exposed to physical strain duringduring work.work. Generally speaking, every third person will suffer fromfrom backback problems,problems, atat leastleast onceonce duringduring hishis lifetime.lifetime. Common back problems are sciatica (spasmodic(spasmodic or continuous pain of nerve situated in, or pertaining to, hip region) and lumbago (a(a painful rheumaticrheumatic conditioncondition ofof thethe lumbarlumbar muscles).muscles).

The spinal column (illustrated(illustrated inin FigureFi~re 4)4) consistsconsists ofof 2424 vertebrae.vertebrae. Between the vertebrae there are elast1celastic cartilage-discs which serve as buffers and which also provide the necessary flexibility to make it possible to bendbend thethe back.back. The discs have a softsoft nucleusnucleus which isis surrounded by a fibrousfibrous ring.ring.

Figure 4.4. 'lbeThe spinal column.column. - 10 -

When liftinglifting oror carryingcarrying a loadload with aa straightstraight back, thethe discs are slowly pressedpressed together.together. The pressure on the back fromfrom thethe loadload isis in this way distributed over a bigger surfacesurface andand duringduring aa longerlonger time. The discs eventually revertrevert toto theirtheir originaloriginal formform afterafter thethe load has beenbeen removedremoved (see(see FigureFisere 5).5). The discs are more sensitivesensitive to pressure when thethe backback isis bentnt thanthan whenwhen itit isis erect.erect. If the pressure is too great or very frequent, the fibrous ring may wearwear and eventually burst andand thethe gelatinousgelatinous nucleusnucleus maymay partlypartly comecome out.out. The person will then suffer from a slipped disc, which is very painful and causes longlong absenceabsence fromfrom work.work. When thisthis rupturerupture causescauses pressurepressure on a nerve itit will givegive riserise toto so-calledso-called sciatica.sciatica. Ways of decreasing the riskrisk of spinal injuries will be further discussed in Section 2.32.3 "Work"Work postures".postures".

Figure 5.5 . When lifting or carrying a load the discs are slowly pressed together. The pressure on the discs is in this way distributed overover aa biggerbigger surfacesurface andand duringduring aa longerlonger time.time . The discs eventually revert to their original form after the load has beenbeen removed.removed .

B. The jointsjoints

The jointsjoints make itit possible forfor different partsparts of thethe skeletonskeleton to move. The end of thethe bonesbones inin aa jointjoint areare coveredcovered withwith cartilage.cartilage. As there are no blood vessels inin thethe cartilage,cartilage, itit cannotcannot regenerateregenerate easily. It may, therefore, get worn out if exposed to too much strain, which is often the case in heavy physical work such as forestry. The jointsjoints inin particular areare exposedexposed toto overload.overload. The moveability ofof thethe jointsjoints usuallyusually decreasesdecreases withwith age.age.

C. The muscles

There are a number of different typestypes ofof muscles with various functions. Together, they make up about 4040 per cent of thethe body weight. The so-called skeleton muscles, which will be dealt with here, are usedused forfor bodilybodily movements.movements. The muscles consist of elongated cells, fibresfibres oror threads.threads. The capability of thesethese toto - 11 - shrink or contract to as much as half their full length is the characteristic of thethe muscles.muscles. The working capacity of thethe musclemuscle isis directly relatedrelated toto itsits lengthlength andand thicknessthickness (the(the numbernumber ofof cells).cells). In the muscles, chemical energy is converted into mechanical energy and heat isis released.released. Oxygen and nutrients, particularly glucose,glucose, are needed for muscular work and are supplied by capillary blood vessels inin thethe muscle.muscle. The blood vessels also taketake away carboncarbon dioxide and other waste products such as lactic acid which result from the chemicalchemical processes.processes. The muscle has very limited abilityability toto store oxygen and nutrients and is, therefore, dependent on a continuous supply of thesethese fromfrom thethe blood.blood.

The number of blood vessels, the thickness of the muscle, and to a certain extent also its length, can be increased if the muscle is used frequentlyfrequently forfor aa longlong time.time. Well-developed muscles will facilitate the work and also strengthen and support the spinal column and joints.joints.

If the musclemuscle contracts and relaxes in a rhythmic way, the workwork is dynamic. But when it isis under tension for a long period of time, it is static. Static work isis moremore tiringtiring thanthan dynamicdynamic work.work. When thethe muscle is under tension, thethe blood cannot flow through thethe muscle.muscle. The muscle will, therefore, not get a sufficient supply of oxygen and nutrients, neither will itit get ridrid of waste products, such as the lactic acid which has aa toxictoxic effecteffect onon thethe muscle.muscle . The accumulation of lactic acid will cause local and painful muscular fatigue.fatigue . The pain will not cease until thethe muscle relaxesrelaxes and allows the blood to pass through itit again. Examples static work are holding thethe hands above shoulder height, or holding d heavy load in the hand(s) forfor a period of time, for instance,instance, a chainsaw, a basket with plants or a bucket with water. Exaw~'~sExamn's ofof dynamicdynamic workwork areare ridingriding aa bicycle,bicycle, debarking a log with a Itlc. ..g-handled",-handled barkingbarking spade,spade, oror walkingwalking in the forest. When thethe work isis dynamic andand thethe supplysupply ofof andand needneed forfor oxygenoxygen and nutrients are in balance inin the muscle, the work can continue for a long time without accumulatedaccumulated fatigue.fatigue .

DD.. Blood circulation and respirationrespiration

Nutrients needed inin thethe musclesmuscles areare absorbedabsorbed by thethe bloodblood when itit passes throughthrough thethe liver,liver, andand thethe bloodblood isis oxygenatedoxygenated inin thethe lungs.lungs. It is the heart which pumps the blood out into the aorta (the(the great artery leading from the left ventricle of the heart). Blood pressure increases during heavy physicalphysical work.work. People with high blood pressure shouldshould be carefulcareful whenwhen engagedengaged inin heavyheavy physicalphysical activity,activity, otherwise the stressstress onon thethe heartheart maymay bebe tootoo great.great. Old people generally have higher bloodblood pressurepressure thanthan youngyoung people.people.

Whenwhen resting,resting, thethe heart pumpspumps betweenbetween 33 toto 66 litreslitres ofof bloodblood perper minute, but inin very physicallyphysically fitfit peoplepeople doingdoing heavyheavy muscularmuscular work it can pump over 3535 litreslitres perper minute.minute. The fit person's resting pulse raterate may be lessless thanthan 5050 beatsbeats per minute, while forfor thethe average person it is somewhere between 60 and 80 beats per minute.minute. - 12 -

When a personperson isis engagedengaged inin heavyheavy physicalphysical work, thethe pulse raterate will always increase,increase, asas wellwell asas oxygenoxygen consumptionconsumption inin thethe muscles.muscles. If untrained, thethe pulsepulse raterate will riserise more, andand faster,faster, thanthan ifif trained. It is therefore possible toto use thethe pulsepulse raterate asas aa relative measure of a person's fitness and also to evaluate how heavy the workload is.is. This will be discussed furtherfurther inin SectionSection 2.22.2 "Energy requirementsrequirements andand physicalphysical workload".workload".

Apart fromfrom providingproviding thethe musclesmuscles withwith nutrientsnutrients andand oxygen,oxygen, andand carrying away waste products, the blood also regulates the body temperature andand itsits water andand saltsalt balance.balance.

OXygenOxygen isis takentaken fromfrom environmental air toto thethe lungslungs during breathing from where it diffuses to the blood when the blood passes through the lungs. At thethe samesame time,time, carboncarbon dioxidedioxide isis emitted.emitted. The "aerobic"aerobic power", or thethe maximal oxygen consumption,consumption, isis thethe person's maximal capacity to consume oxygen in the working muscles during exhaustive exercise.

When thethe muscles'muscles' needneed forfor oxygenoxygen isis met,met, thethe workwork isis calledcalled "aerobic". This means that sugar (1)(1) together with oxygen (2) is converted intointo water (3),(3), carbon dioxide (4)(4) and mechanical energy plus heat (5),(5), asas follows:follows:

Aerobic work:work: ---> 6H 0 + CO + free energy CC66 H12 06 + 602 ---> 6H202 + CO22 +

(1) (2) ((3) 3) (4(4) ) (5)(5 )

When aa too-heavytoo-heavy physicalphysical activityactivity isis performed,performed, thethe supplysupply ofof andand requirement forfor oxygen are notnot inin balance.balance. The muscle will insteadinstead get the energy throughthrough "anaerobic"anaerobic processes".processes". When thethe work isis anaerobic, thethe smallsmall amount of oxygen storedstored inin thethe muscle is very quickly used up resultingresulting inin anan oxygenoxygen shortage.shortage. TheThe sugarsugar (1)(1) without oxygenoxygen isis convertedconverted intointo toxictoxic lacticlactic acidacid (2)(2) andand mechanicalmechanical energy plus heatheat (3)(3) asas follows:follows:

Anaerobic work: 2 free energy Anaerobic work: C6C6 H12 06 --->-> 2 CC33 H6 03 + free energy

(1)(I) (2)(2 ) ((3) 3)

Static work isis anaerobic and leads toto a raisedraised heart raterate and a higher consumptionconsumption ofof energyenergy comparedcompared toto dynamicdynamic andand aerobicaerobic work. Longer restrest pausespauses areare alsoalso neededneeded toto restorerestore thethe oxygenoxygen shortage.shortage. Static and anaerobic work is,is, therefore,therefore, uneconomic and shouldshould be avoided whenever possible.possible. The most commoncommon reasonsreasons forfor staticstatic workwork are poorly designed workplaces, tools and equipment.

2.2. Energy Requirements and Physical Workload

The consumptionconsumption ofof chemicalchemical energyenergy throughthrough thethe intakeintake ofof food,food, andand the metabolic expenditure ofof mechanical energy,energy, areare bothboth expressedexpressed inin kilocalories (kcal)(kcal) oror joulesjoules (J).(J). One kcalkcal isis equivalentequivalent toto 4.184.18 kJ.kJ. One kcal is the amount ofof heat requiredrequired toto raiseraise thethe temperaturetemperature ofof oneone kilogram of water by oneone degree centigradecentigrade fromfrom 14.514.5 toto 15.515.5 degrees.degrees. One kJ represents thethe energy involvedinvolved when physicallyphysically movingmoving aa oneone kilogramkilogram weight one meter by thethe forceforce of oneone Newton. The use of kcalkcal isis now beingbeing replaced with thethe joulejoule unit.unit. - 13 -

Metabolism

The term applied toto thethe chemical processes which are continuously going on in the cells for the cells' survival and activities is "metabolism" and has beenbeen discusseddiscussed brieflybriefly inin thethe precedingpreceding chapter.chapter. These processesprocesses cancan bebe illustratedillustrated asas inin FigureFigure 6.6.

NVTllIENTS

)

Figure 6.6. The term "metabolism" is used to describe the chemical processes which are continuously going on in the cells for their survival andand activities.activities. - 14 -

Basal metabolism

When not performingperforming any physical activity, but lyinglying down, with an empty stomach, there is still a minimum need for energy for "basal metabolism". This means that energy isis necessary forfor thethe maintenancemaintenance of life processes suchsuch as pumping blood, respiration,respiration, cellular metabolism, glandular*glandular* activityactivity andand regulationregulation ofof bodybody temperature.temperature. The basal energy requirementrequirement depends on body size, sex, age, body temperature, environmentalenvironmental temperature,temperature, andand pregnancy.pregnancy. It will vary between 4180-83604180-8360 kJkJ (1(1 000-2000-2 000000 kcal)kcal) forfor adults.adults.

Workwork energy In addition to the energy consumed for basal metabolism, the energyenergy requirement will riserise when performingperforming anyany kindkind ofof physicalphysical activity.activity. The increase will dependdepend onon howhow heavyheavy thethe workwork is.is.

It is possible toto measure, indirectly,indirectly, the consumption of energy by measuring thethe consumptionconsumption ofof oxygen.oxygen. Each litre of oxygen consumed by the body isis equivalent to 20.1 kJ (4.8(4 . 8 kcal) of energy, which is the "calorific"calorific value"value" ofof oxygen.oxygen. When calculatingcalculating thethe oxygenoxygen consumption, the difference of oxygen content between the inhaled (atmospheric) air and thethe exhaled air isis what hashas beenbeen used,used, andand thisthis value isis multiplied byby thethe volumevolume of exhaled air.air.

When discussing thethe physicalphysical workload itit isis sometimessometimes useful to categorize jobsjobs according to how much extra energy per 8-hour workwork day isis requiredrequired asas follows:follows:

< 4180 kJ (<« 1000 work calories) per 8-hour day ...... light work 4180-6688 kJ (1000-1600(1000-1600 work calories)calories) per 8-hour day ...... •... moderately heavy work 6688-8360 kJ (1600-2000(1600-2000 work calories)calories) per 8-hour day • ...... heavy work > 8360 kJ (>(> 2000 work calories) per 8-hour day very heavy work

These figuresfigures are very generalgeneral and theythey depend onon thethe person's aerobic capacity.capacity.

The figures apply toto men and itit isis suggested thatthat theythey be lowered by 25-30% forfor women.women.

Energy consumed forfor basal metabolism and activities outside working hours must be added soso as toto obtain thethe totaltotal energy consumptionconsumption per 24 hours.

By studying energy consumption itit isis possible toto learnlearn about the physical effort of the work. Knowledge about energy consumption is useful when, forfor example, comparing the efficiency of toolstools and work methods, for the scheduling of restrest pauses, and when assessing workers' nutritionalnutritional requirements.requirements. However, it will not provideprovide information on mental strain or other environmental factorsfactors affecting the worker.

* gland: an organ or collection of cells secreting and extracting certain substances fromfrom thethe bloodblood andand transformingtransforming themthem intointo newnew compounds.compounds. -- 15 -

Leisure and energy

Life does not consistconsist ofof restrest andand workwork only.only. Out-of-work activitiesactivities also requirerequire energy which is sometimes referredreferred to as "leisure calories". Fi~reFigure 7 sununarizessummarizes the different kinds of energyenergy requirements. T±'e e figure isis simplifiedsimplified andand couldcould givegive thethe impressionimpression that differences inin dailydaily energyenergy expenditureexpenditure areare duedue onlyonly toto work.work. This is not absolutely true and some people spend a considerable amount of energy on leisure. Also, many people spend their "leisure time" working within thethe informalinformal sector.sector.

-4- csi 5000 •'"0-a o o .~ .,,~ 4000 0- SrE •"o o 3000 v >­ oa '"a) 2000 •'"o -• •1. •'" 1000 o>

1000 1600 2000 3000 WorkWo rk calories calories moderate-moderare per 2424 hh LeveLevell of 1y Light ly IHeavyH eavy I very work heavy heavy I 1 4200 6700 8400 1260012600 kiloJouleskiloJoules per 2424 hh

Figure 7.7. Summarysununary of overall energy consumption of a man compared with his working consumption.consumption. Source: Hettinger inin GrandjeanGrandjean (1982).(1982).

Energy expenditure and physical workload

In Table 1 a number of physical activities, and the corresponding energy expenditure per minute, are listed, toto givegive anan ideaidea of how thethe workload may varyvary betweenbetween differentdifferent activities.activities. The figuresfigures shownshown should,should, however, be takentaken asas approximateapproximate only,only, asas theythey willwill varyvary dependingdepending onon thethe person's body size,size, sex,sex, age,age, fitness,fitness, workwork pacepace andand whatwhat toolstools andand workingworking techniques areare used.used. - 1616 --

Table 1.1. Energy expenditure inin forestryforestry work*work*

kcal**/min/65kcal**/ min/ 65 kgkg man Range Mean

WORK ININ FORESTRYFORESTRY NURSERY - hoeing 5.95. 9 - weeding 4.7 - carrying load of weeds and dumping 4.24. 2

PLANTING - digging drainage ditches with hand tools 8.0 - planting by hand 5.55. 5 -11.2 6.5 - planting by machine 2.8 - tractor driving-harrowing while sitting 3.4 - 5.45.4 4.64.6 - tractor dridriving-harrowingving-harrowing while standingstanding 5.6 - 7.57. 5 6.6

WORKING WITH AXEAXE --HORIZONTAL AND PERPENDICULAR BLOWSBLOiIS Weight of head blows/minblows/ min 1.25 kg 20 5.5 0.65-10.65-1.25. 25 kg 35 9.1 -- 10.610 . 6 9.8 2.0 kg 35 10.0

FELLING, DEBRANCHING, ETC.ETC. - felling 6.8 -- 12.712 . 7 8.68. 6 - debranching 5.25. 2 - 11.6 8.4 - debarking 5.25.2 - 12.0 8.08. 0 - splitting woodwood 8.6 - 9.1 8.8 - dragging firewood 7.8 - 9.8 8.8 - stacking firewood 5.1 - 6.26. 2 5.7 - carrying logs 9.9 - 14.414 . 4 12.1 - dragging logslogs 8.3 - 15.9 12.1

WORK WITH IN FOREST - saw 3.2 - carrying chainsaw 66.5. 5 - cross- by handsaw 6.4 - 10.5 8.6 - horizontal sawing byby handsaw 6.8 - 7.7 7.2 - cross-cutting by chainsaw 2.9 - 5.05.0 4.3 - horizontal sawing by chainsaw 3.6 - 6.46.4 5.45. 4

* Source:Source: AdaptedAdapted freely fromfrom Durnin,Durnin, J.V.G.A.J.V.G.A. andand Passmore,Passmore, R.R. "Energy workwork and leisure". Heinemann, London,London, 1967.1967.

** for kJ multiply by 4.18.4.18. - 17 -

The energy consumptionconsumption when working with a tool or aid, such as an axe, handsaw, shovel or wheelbarrow, will vary considerably depending on the type, design andand maintenancemaintenance ofof thethe tooltool oror aid.aid. Figure 8 shows an example of thisthis difference inin energyenergy expenditure per output of work, when using three typestypes ofof sawssaws forfor treetree fellingfelling (sal).(sal). From this study, which was carried out inin India,India, thethe bowsaw (Raker(Raker 2:1)2:1) was inin thethe given circumstances a more economical alternative than the two-man (Raker 2:1)2:1) andand the one-man crosscut saw (Peg-tooth) whenwhen comparing energyenergy expenditure perper squaresquare metre.metre.

12':;0.2 illC) Two-T"o- mon crosscut sawsaw (Raker(Raker 2:1)(n.7)2 - I)(n~71 illC) Bowsaw/Bowsow (Raker(Rok.r 2:1)2-1) (n'S)(n.8) C)G) 0ne-manOne-man crof.scutcro~cut saw(Pe9-tooth)(n'8)saw( Peg-tooth)(n'S)

kcoljminkcal/min cm2/mincm)'min kcal/mtkcoljm'

7,5 150I~O 1050 T

5-5 100 - 800 -

600- 25 ', 50

1+00- -1 123 123'iOO123 123 o o PhysiologicalPhysiologicol OutOutput put crfof EnergyEnorgy load Workwork QxplZnditurlZexpenditure pqrper 5q.sQ. M.m.

Figure 8.8. Comparison ofof threethree typestypes ofof sawsaw inin fellingfelling salsal treestrees inin India.India. Source: Hansson, Lindholm,Lindholm, BirathBirath (1966).(1966). -18 -

Figure 9 gives a further example from the same study, showing the significance of tooltool maintenance.maintenance. The mean value of energy expenditureexpenditure perper metre of sawn wood was 120% higher when using incorrectly maintainedmaintained .

Saw No.I-~No.1- 5.. LocallLaccll~ usedusod and maintainedmainlainod two-manl",a-man craooculcros3cut Soress~ (Pcross culcut sawoa", (R.s-tooth)(P<:l-tooth)

cm7minem 2/ mIn. kcal/m2kcal/m' 800 800 r

600000 600bOO r

400 400

200

123~5 b o Output crfof ",orkwork EnerSIdEnergy, expenditure"xp~nditure per sq.m. Figure 9.9. The significance ofof tooltool maintenance.maintenance. Source: Hansson, Lindholm,Lindholm, BirathBirath (1966).(1966).

It waswas shown in another study how it was possible by redesigning or adjusting a wheelbarrow's wheel-diameter, tyretyre pressurepressure (rubber(rubber tyres),tyres), height of handles above groundground level,level, andand distribution ofof thethe loadload betweenbetween the wheelwheel axle and handles to increaseincrease the loading capacity by 40% without increasing the physiological workload.workload.

Efficiency

Sometimes the metabolism inin thethe human body isis compared toto a combustion engine. This is because of the similarities between the two when it comes toto the efficiencyefficiency toto convertconvert chemicalchemical energyenergy intointo mechanical energy.energy. This is illustratedillustrated withwith twotwo diagramsdiagrams inin FigureFigure 10.10. - 19 -

INPUT: 100% Chemical Energy

Losses Losses

Heat 70%

in the statestate of:of:

evaporation

Exhaust gases 35%35% conduction

convection Cooling water 30%30% radiation Radiation 6%6%

Apparatus 4%4% otherOther losses 5% e.g. carbon dioxide,dioxide, urine

OUTPUT: 25% useful energy ' 25% useful energyenergy (maximal)(maximal)

A. Combustion engine B. Metabolism inin humanhuman body

Figure 10. The energy-converting efficiency of the metabolism in the human body comparedcompared toto aa combustioncombustion engine.engine. Source: IngeniarIngemar EileEile "Ergonomi"."Ergonomi". Hermods, 1973.1973.

When comparingcomparing thethe energyenergy consumptionconsumption (input)(input) withwith thethe measurablemeasurable mechanical energy (output),(output), itit isis evidentevident thatthat onlyonly aa smallsmall portionportion isis utilized. In the human body thethe heatheat losseslosses amountamount toto approximatelyapproximately 70%.70%.

If work is carried out inin thethe most efficient way, by using thethe large muscles in the legs,legs, inin dynamicdynamic movements andand with aa pacepace whichwhich allowsallows thethe muscles to work aerobically, thenthen itit isis possiblepossible toto obtainobtain 25%25% usefuluseful energy. Under less favourablefavourable conditionsconditions with entirely staticstatic efforteffort thethe efficiency will bebe zero.zero. Figure 11 gives some examples of the efficiency in different activities. - 2020 -

Silling Standing iCheelingKn~;ng Stooping 3-S%3-5% 8-10% 30-40%.3O-.qo~ 50-60%

Figure 11 Relative increaseincrease inin energyenergy consumptionconsumption inin differentdifferent postures.postures.

For example, it can be deduced fromfrom FigureFigure 1111 thatthat efficiencyefficiency cancan bebe considerably increased simply by avoiding kneeling or stooping positions whenever thisthis isis possible (e.g.(e.g. when fillingfilling plant pots with earth).earth).

Considering the number of workers suffering from undernourishment and at the samesame timetime having toto waste theirtheir scarcescarce energy because of poor work postures, the importanceimportance ofof workplace arrangements and tools permitting ergnomically favourablefavourable workingworking positionspositions isis evident.evident.

Body temperaturetemperature

The optimal temperature of inner organs of the human body is about + 37°370 8.S. It fluctuates from about + 36.536.5 C during thethe night toto aboutabout + 37.5 C during thethe day.day. It is lowest during the ea6lyeaoly hours ofof thethe morning. A variation ofof thethe temperaturetemperature betweenbetween ++ 3636 C and + 40°C400 C is within thethe normal range.range. The temperature varies between different parts of the body. Under normal comfortablecomfortable conditionsconditions itit is,is, foisfo example,example, only 0 o about + 30°30 C in the fingertipsfingertips and toes,toes, but about + 35 C in thethe trunk.trunk.

Heat production

At least 70% of thethe totaltotal inputinput ofof energy isis convertedconverted intointo heat as a result of metabolism inin everyevery livingliving cell.cell. When resting,resting, most ofof thisthis heat (70%) is produced in thethe bowels andand thethe centralcentral nervousnervous system,system, whichwhich havehave a high metabolism, andand inin thethe musclesmuscles (20%).(20%).

Whenwhen carrying out physical activity, thethe production of heat will increase, mainly inin thethe muscles.muscles. During very heavyheavy physicalphysical workwork itit maymay bebe ten times higher, or even more, compared toto when resting.resting.

Control of the heat balance

Basically, the human body followsfollows thethe samesame general physical lawslaws as any other object. The principle is that heat always flows fromfrom a warmer to a colder area. - 21 -

There is a centre inin the brain for the control of the mechanisms which regulateregulate thethe bodybody temperature.temperature. To maintain thethe temperaturetemperature of thethe body, particularly inin thethe innerinner organs,organs, the excess heat produced there must be removedremoved andand emittedemitted toto thethe environmentenvironment outsideoutside thethe body.body.

Most of thethe transporttransport ofof thethe internalinternal heat isis carriedcarried out by thethe blood. The heat is mainly emitted through the dilated blood vessels in the skin. From the skin the heat partly leaves by the "dry" way, which is by radiation and convection, a minor part also by conduction, and partly byby the "wet""wet" way -- byby evaporationevaporation ofof water.water.

Air velocity andand thethe difference inin temperaturetemperature between thethe air and the skin are thethe determiningdetermining factorsfactors forfor convection.convection. The decisive factor for radiation is the difference inin temperaturetemperature between the skin and the adjacent surfaces.surfaces. Conduction of heat takes place when there is direct contact with aa surroundingsurrounding medium.medium. From an ergonomic point of view, conduction is of less importance, apart from local conduction from/to the feet and hands.hands. Out of the total evaporation, 2/5 of the heat leaves by the exhaled air andand 3/53/5 byby thethe secretionsecretion ofof sweatsweat inin thethe skin.skin.

If the skin is heated, as, forfor example, when taking a hot bath, the heat transport will bebe thethe reverse.reverse.

The optimal surrounding temperaturetemperature for human beings, if naked, is 2828°C.0 C. When restingresting atat thisthis temperaturetemperature thethe heatheat producedproduced byby thethe metabolicmetabolic processes will be inin balance with thethe heat lost throughthrough convection,convection, radiation and evaporation.evaporation. About 75% leaves through convection and radiation and 25% throughthrough evaporationevaporation underunder suchsuch conditions.conditions.

The control of blood circulation and the secretion of sweat in the skin are the mostmost important heat-regulating mechanisms of the body in cases of an increased heatheat load.load. There are about two million sweatsweat glandsglands inin thethe skin. They are activated in a certain order, starting with the big surfaces on thethe legslegs andand thethe trunk.trunk. If the sweat evaporates from the skin this will coolcool down thethe skin.skin. When the whole body is wetted the cooling effect isis most efficient.efficient.

To enable an increasedincreased transporttransport of heat toto thethe skin,skin, thethe heart raterate and blood pressure will rise.rise. More blood will flowflow throughthrough the skin and lower priority is given to thethe blood supply to the muscles and digestive organs. This will leadlead toto aa reducedreduced performance andand efficiencyefficiency of thethe muscles and a reduction of . thethe digestive processes.

The effects of heat and other climatic factorsfactors on thethe human body and the capacity forfor work areare furtherfurther discusseddiscussed inin SectionSection 3.1.13.1.1 "Climate"."Climate". - 22 -

Heart rate

Oxygen consumption is a measure of energy consumption which, under certain conditions, has a linear relationship with the heartheart rate as shown wiwith th curve DD inin FigureFigure 12.12.

f Working under hot conditions Static muscular work Dynamic work involvinginvolving few rrusclesmuscles

Dynamic woworkrk involving genyrmny musclesrruscles

Energy consumption with z=a41111. increasing stresssstresss -

Figure 12. Increase in heart raterate associatedassociated withwith variousvarious typestypes ofof stress.stress. Source: Grandjean (1982).(1982) .

Sometimes, however, the oxygen (energy)(energy) consumption underestimates the stress on the heart, and thethe heart raterate risesrises fasterfaster than thethe oxygen consumption. This will happen when, forfor instance,instance, working inin a hot environment (see(see curvecurve A), when the work isis staticstatic (see(see curve B), or when only a few muscles are involvedinvolved inin dynamic work (see(see curve C). Of course,course, the combination of thesethese factorsfactors will increaseincrease thethe stressstress on thethe heart even more.

measuringMeasuring thethe heart raterate (pulse)(pulse) is,is, therefore,therefore, aa useful way ofof assessing thethe realreal workload.workload. It is also the simplest way toto assessassess thethe strain on thethe worker.worker.

When controlledcontrolled forfor factorsfactors suchsuch asas airair temperature,temperature, musclesmuscles used,used, type of work, consumption of food, coffee, etc., or smoking justjust before study there is a relationshiprelationship between workload, oxygen consumption, heart rate, lung ventilation andand bodybody temperature,temperature, asas isis shownshown inin TableTable 2.2. - 2323 -

Table 2. Metabolism, respiration, temperature and heart rate as indicators of workload.

Assessment Oxygen Lung Rectal Heart of workload consumption ventilation temperature rate Litres/min. Litres/min. °c°C Pulses/min.

"Very low"low" 0.25-0.3 6-7 37.5 60-70 (resting) "Low" 0.5-1 11-20 37.5 75-100 "Moderate" 1-1.1-1.5 5 20-31 37.5-38 100-125 "High" 1.1.5-2 5-2 31-43 38-38.5 125-150 "Very high" 2-2.5 43-56 38.5-39 150-175 "Extremely high"high" 2.4-4 60-100 over 39 over 175175 (e.g. sport)

Source: E.H. ChristensenChristensen inin GrandjeanGrandjean (1982).(1982).

2.3 Work Postures

Static muscular work, back disease and worn-out jointsjoints caused by poor work postures have already beenbeen mentionedmentioned inin Sections 2.12.1 andand 2.2.2.2. These and other problems relatedrelated toto work postures will be furtherfurther discussed inin this section.

A. Handling of loads

Lifting In forestry, manual lifting and carrying of loads isis very common but should be avoided or limited as much as possible, particularly when the load is heavy and/or has toto bebe liftedlifted fromfrom aa lowlow level.level. It is difficult to give figures for the optimal oror maximal weight of a loadload toto be lifted,lifted, as there are so many other factors to take into consideration, such as shape, size, handles, lifting aids and the frequency of the lifting. In any case, the lifting of too-heavy loadsloads must be avoided. Sometimes upper limitslimits have been set forfor practicalpractical purposes.purposes.

If lifting is unavoidable, all possible precautions should be taken to facilitate the work soso as toto preventprevent painful back problems which may cause lingering absenteeism.absenteeism.

If the lifting is to be done frequently, the workplace can be equipped with a lifting aid suchsuch as aa hoist or crane.crane. In permanent workplaces, thethe loadload cancan bebe placedplaced onon aa specialspecial ramp,ramp, soso asas toto allowallow manualmanual lifting from a convenient height. This should be at least 40 cmem above ground level.level. There should bebe sufficientsufficient spacespace forfor thethe feetfeet under thethe ramp, so that the workerworker can stand near the load when lifting.

If the load does not have handles, the worker may use a harness or rope. For example, when lifting logs fromfrom the ground, the arms can be extended by the use of hooks andand tongs,tongs, which will allowallow thethe backback toto bebe kept straight. SeeSee FigureFigure 13.13. - 24 -

Figure 13.13 . To allow the back to be kept straight when lifting a log from the ground, the arms can be extended by the use of hooks, tongs,tongs, etc.etc.

Much backback troubletrouble cancan bebe avoidedavoided byby thethe useuse ofof properproper liftinglifting techniquestechniques.. When liftinglifting with thethe backback bentbent forwardforward andand thethe legslegs straight,straight, as shown inin FigureFigure 14A,l4A, thethe pressure onon thethe lowerlower vertebraevertebrae will concentrate on onlyonly aa smallsmall partpart ofof thethe discs.discs. As thethe discs are very sensitive to uneven pressure,pressure, thethe riskrisk ofof injuryinjury willwill bebe great.great.

Instead, the lifting shouldshould bebe donedone with:with: a straight back inin an erect position the knees bent, and the feetfeet a bit apart and with aa goodgood foothold;foothold; as shownshown inin Figure 14B.l4B.

The pressure on thethe discs will inin this way be distributed evenly and the riskrisk ofof backachebackache willwill diminish.diminish.

In addition:

the load shouldshould bebe keptkept nearnear thethe centrecentre ofof thethe body.body. ToTo holdhold 1010 kg.kg. at a distance 80 cmem fromfrom thethe body isis equivalent toto thethe samesame load on the body as holding 5050 kg. near thethe body;

the body shouldshould bebe usedused asas symmetricallysymmetrically asas possible.possible. To lift in a twisted posture inin particular will increaseincrease thethe risksrisks of causing injuries toto muscles andand joints.joints. - 25 -

Figure 14. The distribution of the pressure on the intervertebral discs when lifting a loadload with bent back (A)(A) and with straight back (B).(5). - 2626 --

Osr,W24~4MAIM

10~

A B c D

Figure 15.15. The pressure on thethe disc between the thirdthird and fourthfourth lumbar vertebrae (in(in kg. per unit of surface) when lifting loads in different postures.postures. Source: Nachemson andand ElfstromElfstrom inin GrandjeanGrandjean (1982).(1982) .

It is not only pressure causedcaused by heavy loads but more often wear and tear on the discs fromfrom repetitiverepetitive harmfulharmful movementsmovements whichwhich causescauses injuries.injuries.

As has beenbeen statedstated before,before, oneone inin everyevery threethree personspersons willwill suffersuffer from back pain once during theirtheir lifetime.lifetime. The absenteeism causedcaused byby backback injuries is particularly high among workers engaged in physically active work as an unhealthy back will bebe more ofof aa hindrancehindrance forfor themthem thanthan forfor somebody whowho is not dependent on being physically mobile to carry out the job.

Carrying loads

Carrying of heavy loads isis staticstatic work which producesproduces locallocal muscular effects, such as fatiguefatigue duedue toto impariedimparied circulationcirculation andand lacticlactic acidacid accumulation and, eventually, underunder extremeextreme conditions,conditions, itit may produceproduce inflammation of thethe jointsjoints andand otherother injuries.injuries.

Carrying a load on the back inin a rucksackrucksack oror with aa harness designed for the purpose will decrease the physical strainstrain and energy consumption as compared with carryingcarrying itit onon thethe shouldershoulder oror inin oneone hand,hand, which givesgives aa high static load on thethe shouldershoulder oror arm.arm. - 27 -

Carrying loads using a yoke is usually less strenuous and less energy-consuming thanthan carryingcarrying itit byby otherother manualmanual means.means. A study showed that a person could carrycarry 2020 kg 4.54.5 km consuming 1045 kJ (250(250 kcal) if he used a yoke, as comparedcompared with only 3.93.9 kmkm when carrying it on thethe back.

The lever principle In the body, the skeleton bones serve as levers upon which the muscles work. To make use of levers also outside the body is particularly helpful when handlinghandling heavyheavy loads.loads.

When handling loadsloads manually, considerableconsiderable energy can be savedsaved and efficiency can be gained by thethe use of very simple and cheap tools and equipment with anan ergonomicergonomic design.design. Many injuriesinjuries willwill alsoalso bebe prevented,prevented, leading toto lessless absenteeism.absenteeism.

B. Standing or standing/Walkingstanding/walking

Many jobsjobs are carriedcarried out inin a standingstanding oror standing/Walkingstandingjwalking position.poSition. It may be the only possible way to perform a particular job, or at least the most ergonomic way.way. Very heavy physicalphysical work isis usually done inin aa standing positionpoSition so as to get enough muscular strength to carry out thethe work. If the work isis not physically heavy and thethe worker can move around with a freefree choicechoice ofof bothboth thethe movements andand thethe pace,pace, andand ifif thethe workerworker can sit down once in a while, the conditions are, from a physiological point of view, veryvery favourable.favourable. Light, dynamic work isis not,not, however,however, common in the forest andand forestforest industries.industries. In the forest, thethe dynamicdynamic work isis oftenoften tootoo heavy,heavy, andand inin forestforest industriesindustries manymany workersworkers havehave toto workwork in a more or less fixed standing position, coupled with repetitiverepetitive and often one-sided movementsmovements ofof thethe arms.arms.

When restrictedrestricted toto aa standingstanding positionposition thethe bloodblood circulationcirculation willwill decrease in thethe legslegs and causecause increasedincreased bloodblood pressurepressure inin thethe veins, which after somesome timetime causescauses pain.pain. It may also cause diseases suchsuch asas varicosevaricose veins (the(the veins become enlarged) ifif thethe personperson hashas toto standstand forfor longlong periods inin thethe job.job.

manyMany parts ofof thethe bodybody will bebe inin aa staticstatic statestate when standing,standing, whichwhich is tiring, particularly forfor thethe back.back. The strainstrain on the back can be considerably decreased ifif there isis enoughenough spacespace toto move oneone footfoot forward,forward, and in this way change thethe centre of gravitygravity ofof thethe body.body.

This isis not possible, however,however, ifif oneone footfoot hashas toto controlcontrol aa pedal,pedal, which will putput thethe entireentire bodybody weightweight onon thethe otherother leg.leg. The pedal maymay eveneven be placed well above floorfloor level, forcingforcing thethe operatoroperator alsoalso toto liftlift thethe weight ofof thethe legleg eacheach timetime thethe pedalpedal isis toto bebe pressedpressed down.down. Or the pedal may be placed tootoo farfar from,from, oror atat aa wrongwrong angleangle to,to, thethe placeplace wherewhere thethe hands areare occupied.occupied. The result will then be a twisted or one-sided work posture, which isis notnot onlyonly uncomfortableuncomfortable andand tiringtiring butbut alsoalso unhealthy.unhealthy. Figure 16 shows a worker in a somewhatsomewhat acrobatic posture when operatingoperating an electrical crosscut saw inin a plant. - 28 -

Figure 1616.. An operator of an electrical chainsaw inin a plywood plant in an uncomfortable andand dangerousdangerous posture.posture.

When thethe worker hashas toto workwork inin aa standingstanding position,position, atat leastleast therethere should always be a chair within easy reach,reach, to be used during pauses in the job.

C.c. sittingSitting or sitting/standing

Many jobsjobs couldcould bebe done,done, whollywholly oror partially,partially, inin aa sittingsitting oror sitting/standing position, after quite small changes of the workplace design.

A high stoolstool allowingallowing forfor aa half-sittinghalf-sitting postureposture cancan bebe aa suitablesuitable compromise which will provideprovide somesome relaxationrelaxation ofof thethe tensiontension inin thethe legslegs and thethe back.back. The reach will still be fairly good and it is possible to stand upup quickly when necessary forfor certain elements of the jobjob or forfor safety reasons (see( see FigureFigure 17).17) . - 29 -

Figure 17.17. A high stoolstool allowing forfor aa half-sittinghalf-sitting posture.posture.

The stool is,is, however, toto be seenseen as an emergency solution for the otherwise continuouslycontinuously standingstanding worker.worker. A regularregular sittingsitting position isis preferable ifif thethe jobjob doesdoes notnot requirerequire bigbig muscularmuscular effort.effort. A sittingsitting position will taketake awayaway muchmuch staticstatic work, providedprovided that:that:

the chair is of an appropriate height allowing the feet to rest on the floor with thethe kneesknees bentbent inin almostalmost aa rightright angle.angle. The height of the chairchair shouldshould thereforetherefore bebe adjustable;adjustable;

there is enough space forfor thethe knees under thethe ;

the chair hashas aa backrest;backrest;

the work object isis at the rightright height, soso as not toto expose thethe arms and shoulders to unnecessary static effort, and toto avoid sittingsitting with aa bentbent neckneck andand backback soso asas toto seesee thethe objectobject properly;properly;

the chair isis functional.functional. There isis no suchsuch thingthing asas thethe "ideal"ideal chair". The chair will only be ergonomically suitable ifif it functions well for thethe particular workerworker inin thethe particularparticular job.job. - 3030 --

D. workplaceWorkplace design and anthropometry

Workplace design

When planningplanning aa workplace therethere are a numbernumber ofof simplesimple rulesrules relatedrelated to workplace design which should be kept in mind, so as to protect the worker fromfrom uncomfortable, tiring,tiring, unhealthy and dangerous conditions.conditions. The first rule is that "no work posture is so good that it can be held for a long period of timetime without variation".variation". Below is a listlist ofof thethe veryvery basicbasic conditions either toto aimaim for,for, oror toto avoid:avoid:

To aim for:for:

a) a physically light and dynamic work which allows the worker to move freely andand:change change between standing/Walking and sitting positions;

b) a sittingsittin~sition position ifif thethe workwork isis lightlight butbut whenwhen thethe conditionsconditions under a) aboveve areare notnot possiblepossible toto achieve;achieve;

c) an appropriateappr0tfiiate chair design, taking intointo account the size of the worker, thee heightheight ofof thethe placeplace ofof thethe work objectobject andand thethe need for movements to thethe sideside or supportsupport forfor thethe armsarms andand back;back;

d) a support, e.g. a stool, to providerovide a half-sittinghalf-sittin positionsition when the work has to be partially doneone in1n aa standingstan 1ng position;pos1t10n;

e) a chair within easy reachreach for any pauses which may occur, for jobsjobs Whichwhich have toto~ be donedone inin aa standingstanding position;position;

f) sufficient space for comfortable andand safesafe movements;movements;

g) placing of work object, controls, displays,dis la s, etc., which are frequently used, within comfortable reach so as to avoid any awkward and tiring movements;

h) to havehave a clear and logical design and arrangement of displays so as to avoid mistakes.mistakes.

To avoid:

physically heavyheavy work;work; twisted, unsymmetrical,unsymmetrical, crooked, repetitive or fixed body postures; a combination ofof demandsdemands forfor precisionprecision workwork andand muscularmuscular force;force; -31.-- 31 -

static work e.g.:e.g.:

to maintain aa highhigh levellevel ofof efforteffort forfor 1010 secondsseconds oror more;more; to maintain aa moderate efforteffort forfor oneone minuteminute oror more;more; to maintain a slight effort (about(about one third of maximum force) for four minutes or more;

Common examplesexamples ofof suchsuch effortsefforts are:are:

bending thethe back eithereither forwardsforwards oror sidewayssideways frequently;frequently; holding thingsthings inin thethe arms;arms; holding thethe armsarms stretchedstretched outout horizontally;horizontally; holding thethe armsarms aboveabove shouldersshoulders height;height; putting thethe weight onon one legleg while thethe other works a pedal; standing inin oneone place forfor longlong periods;periods; pushing and pulling heavyheavy objects;objects; sitting erect without backback support;support; bending thethe neckneck excessivelyexcessively backwardsbackwards oror forwards;forwards; applying an unnatural graspgrasp ofof handhand gripgrip oror tools.tools.

(Adapted freely from Grandjean, E., 1982).

The solution may not always be as simple as indicatedindicated here, and a deeper analysis of the problem may be needed. If aiming to apply ergonomic principles when planning and organizing work, purchasing tools and equipment, etc., this will probably resultresult in a significant reductionreduction of occupational accidents and diseases, absenteeism and labour turnover and energy consumption, andand anan increaseincrease inin workwork efficiency.efficiency.

Anthropometry

To design and construct tools,tools, machines and workplaces which will fit the workerworker requires knowledge of measurements and motions of the bodyparts which are decisive inin thethe particularparticular job.job. This study isis known as "anthropometry"."anthropometry" . When tryingtrying toto fitfit e.g.e.g. thethe toolstools toto thethe worker withwith thethe helphelp ofof anthropometric data, the enormous variations in body size between races,races, men and women, andand eveneven betweenbetween individualsindividuals ofof thethe samesame sexsex andand racerace have to be taken into account.

To design a workplace toto fitfit thethe average worker will inin many cases have unacceptable consequencesconsequences forfor eithereither thethe tallertaller oror thethe shortershorter persons or both. This isis illustratedillustrated inin FigureFigure 18.18. -32-- 32 -

Figure 18.18. To design a workplace to fit the average workerworker will in many casescases have unacceptable consequencesconsequences for either the taller or thethe shortershorter persons,persons, oror both.both.

Obviously, the workplace must in some cases be designed with the taller workers inin mind andand inin otherother casescases thethe shortershorter ones.ones. It is forfor instance easier toto provideprovide aa shortshort personperson withwith anan aid,aid, suchsuch asas aa lowlow stoolstool to rest the feet on, than it would be to make a hole under the desk for the person with long legs so as to provide sufficient space for the legs under the desk.

As allall people areare different,different, thethe workplace shouldshould preferably be adjustable to fit workers ofof variousvarious size.size. InIn somesome casescases thisthis cancan bebe done,done, but very oftenoften itit isis notnot possible.possible.

Manufacturers of tools, machines and equipment in industrialized countries design their products using anthropometric data of people from their own countries.countries. The products may, however, be sold to and used by people inin otherother countriescountries ofof muchmuch differentdifferent bodybody size.size.

In forestry in developing countries the application of anthropometric data would above all be ofof use inin casescases of locallocal manufacture ofof toolstools and equipment, for the design of workplaces in forest industry and when purchasing machinesmachines andand toolstools fromfrom otherother countries.countries. workingWorking techniques

Mostmost of the heavy physical work in forestryforestry is carried out in standingjwalkingstanding/Walking or squatting postures, and preferably by moving the whole body so as to make use of thethe big muscles inin thethe body. In some tasks such as sawing with a handsaw, planting with a plantingplanting hoe, debarking with a spade, or cutting with an axe,axe, thethe properproper workingworking techniquetechnique isis toto useuse wide,wide, rhythmic and swinging body movements and the strong muscles of lower limbs as much asas possible.possible.

In the technique of a flywheel the kinetic (motive)(motive) energy of an object inin motion isis utilized.utilized. This principle cancan also bebe usedused inin manualmanual work, forfor example when throwingthrowing aa heavyheavy objectobject fromfrom a lowerlower levellevel toto a - 33 - higher one.one. If the object is first set into a swinging motion andand thenthen atat the right moment it is let loose, it will continue in its upward movement by itself, savingsaving thethe worker'sworker's energy.energy.

Another exampleexample isis cuttingcutting withwith anan axe.axe. If pulling the weight of thethe arms and the axe down in the cutting movement by using the force of gravity on the body and axe, the resultresult is a powerful blow without overstraining the arm muscles.

2.4 NutritionNutri tion

Nutrition isis concernedconcerned with thethe foodfood we eateat and how thethe body uses it.it. Food is anything which will nourishnourish usus whenwhen takentaken intointo thethe body.body. The lack of food contributes toto lowerlower resistanceresistance to disease and leadsleads toto higher rates of accidents andand absenteeism,absenteeism, asas wellwell asas aa lowerlower workwork output.output.

Energy value

It is essential to know how much energy a worker requiresrequires to be able to carry out a particular jobjob whenwhen discussingdiscussing thethe worker'sworker'S foodfood intake.intake. The energy content of thethe foodfood eaten by the worker has a direct effect on the capacity toto carrycarry outout muscularmuscular work.work. If the job requires, for instance 8,360 kJ (2,000(2,000 kcal) inin addition toto thethe approx. 8,360 kJkJ (2,000(2,000 kcal) needed in the basic metabolism and forfor off-work activities, the total daily requirement will be 16,720 kJkJ (4,000(4,000 kcal.).kcal.). If the food intake provides only 12,540 kJ (3,000(3,000 kcal), thisthis will affect the person's working capacity, as only 4,1804,180 kJ (1,000(1,000 kcal) will remainremain available for the job.job. The worker will cope with thethe situationsituation either by working at a slower pace or by reducing the effective working time,time, by taking more frequentfrequent and longer pauses, oror aa combinationcombination ofof these.these. If only 50 percent of the energy needed for the jobjob is available, itit isis evident that thethe output will also be only 5050 percent.percent.

If the person does not adjust the work output to the available energy, the result will be a loss of body weight. Therefore, to adjust isis a biological necessity forfor survival, and has nothing to do with low motivation oror laziness.laziness. The energy expenditure andand intakeintake dodo not,not, however,however, have to be in balance each day, but over a period of time.

It is not only the amount of energy which is of importance and which will affect thethe worker's healthhealth andand capacitycapacity toto carrycarry outout physicalphysical work, but also the nutritive valuevalue ofof thethe food.food. There are six main categories of nutrients, which areare allall necessarynecessary forfor nourishingnourishing thethe body:body: to build up and maintain tissues, to supply energy, and to regulateregulate body processes. They are:

11.. Carbohydrates, whichwhich areare thethe majormajor sourcesource ofof energy.energy. Carbohydrates are normally needed inin thethe greatest quantities oror inin greatergreater quantities thanthan thethe others.others. They are usually foundfound inin thethe cheapest foodstuffs. Examples ofof foodfood richrich inin carbohydratescarbohydrates areare rice,rice, maize, cereals, potatoes, cassava, tapioca,tapioca, andand breadfruit.breadfruit. Some of these alsoalso containcontain protein.protein. Cassava contains very little protein, however. - 34 -

Sugar is another source of carbohydrates.carbohydrates. It is, however, often comparatively more expensive thanthan otherother sources.sources. Pure sugar gives only so-calledso-called "empty"empty calories", providing no other nutrients than the energy itself, but as the body converts sugar veryvery quickly into energy readyready to be used, it can be important for workers engaged in very heavy physicalphysical work.work. Sugar is, however, harmful toto thethe teeth,teeth, causing dental caries,caries, whichwhich affectaffect manymany forestforest workers.workers.

The energy value ofof carbohydratescarbohydrates isis ca.ca. 1717 kJkJ (4(4 kcal)kcal) perper gram.gram.

2. Fats and lipids, which have the highest energy value, ca. 38 kJ (9 kcal)kcal) per gram. Fats are important sources of energyenergy and are particularly essential for persons engaged in heavy physical work and who thereforetherefore requirerequire largelarge quantitiesquantities ofof energy.energy. Fat provides some of thethe energy inin thethe dietdiet withoutwithout makingmaking itit tootoo bulky.bulky. Fats also stay longer in the stomach than carbohydrates or protein, and give prolonged satiation.satiation. Common fatfat sourcessources areare oils,oils, butter,butter, margarine, lardlard andand nuts.nuts.

3. Protein, which has thethe samesame energyenergy valuevalue asas carbohydratescarbohydrates -- ca.ca. 17 kJ (4(4 kcal)kcal) perper gram.gram. The rolerole of protein isis toto buildbuild upup andand maintain thethe muscularmuscular tissue.tissue. Besides being necessary as a body builder, proteinprotein isis needed forfor thethe formationformation of essentialessential bodybody compounds such as enzymes, hormones and antibodies, and for the regulation of the water balance. Protein will eventually provideprovide energy, ifif carbohydratescarbohydrates andand fatsfats areare insufficient.insufficient. This is,is, however, aa misusemisuse ofof expensiveexpensive andand valuablevaluable protein.protein.

Sources of animal protein include milk, eggs, fish, poultry and meat. Vegetable protein isis suppliedsupplied mainly by beans and other leguminous crops, which are cheaper and are the major dietary sources of protein for the bulk of the labour force in developing countries. The quality of protein in the diet is determined by its digestibility andand aminoamino acidacid pattern.pattern.

The human body must be providedprovided with protein daily. Generally, a sufficient protein intake for adults is 0.75 gram per kg body weight perper day.day. Adolescents needneed moremore proteinprotein thanthan adults.adults.

The intakeintake of protein differs aa lotlot betweenbetween countries,countries, depending on availability andand socio-culturalsocio-cultural andand economiceconomic factors.factors. People in several developing countries have a very low protein intake. Sometimes thisthis lacklack of proteinprotein isis copedcoped with byby means ofof a metabolic adaptationadaptation toto thethe lowlow intake.intake. By adaptation aa decreasedecrease of the breakdown ofof body protein will occur,occur, soso asas toto facilitatefacilitate the maintenance of an equilibrium betweenbetween protein intakeintake and protein breakdownbreakdown atat thethe lowerlower intake.intake. In order not toto disturb this delicate state of balance, persons who have adapted to low intakes will avoid heavyheavy andand prolongedprolonged muscularmuscular efforts.efforts. If these persons are put on heavy physical work, theythey must firstfirst forfor somesome time be provided with a diet richrich inin proteinprotein andand energy.energy. - 3535 -.-

4. Minerals, which are necessarynecessary forfor thethe body's normal functioningfunctioning and growth. Examples are calcium and phosphorus, whichwhich are found in the bones andand teeth.teeth. Calcium is also necessary forfor normal functioning of thethe nerves.nerves. Iron is a constituent of thethe bloodblood haemoglobin, which transportstransports oxygenoxygen inin thethe blood.blood. Iron deficiency may causecause anaemia.anaemia. There is evidence that iron-deficiencyiron-

The sources of minerals areare milk,milk, eggs,eggs, cheese,cheese, meat,meat, fish,fish, shell-fish and vegetables.vegetables.

Minerals dodo notnot havehave anyany energyenergy value.value.

5. Vitamins, which are needed inin smallsmall quantities as regulatoryregulatory substancessUbstances forfor life processesprocesses andand goodgood health.health. Deficiency of certain vitamins will cause diseases, for instance, lack of vitamin A will affect thethe eyeseyes (in(in severesevere cases even causing blindness); cardiac, nervous and neuromuscular changes will occur due to beriberi, which isis causedcaused by vitaminvi tamin BlB (thiamin)(thiamin) deficiency. Of course, these diseases will also affect the person's work efficiency.efficiency .

Fats are carriers of thethe fat-solublefat-soluble vitaminsvitamins A,A, D, E and K The main sources forfor thethe water-soluble vitamins C and B-complex are fruit and vegetables,vegetables, which should preferably be eaten raw or only lightly cooked so as not to destroy vitamin C. Vitamin C is particularly importantimportant asas itit improvesimproves the body's capacity also to absorb other nutrients fromfrom food.food.

The requirementrequirement for thethe amount of vitamins does not vary with the heaviness of thethe work.work. The only exception is vitamin B which will be needed inin bigger quantitiesquantities byby aa personperson engagedengaged inin heavyheavy work.work. vitamin B deficiency isis commoncommon inin thethe FarFar East.East. This can partly be relieved by using undermilled, parboiled or enriched rice as the major staple food insteadinstead of thethe generally more appreciatedappreciated white rice. Brown rice has a superior nutritional value compared to white ricerice inin carbohydrates,carbohydrates, calcium,calcium, phosphates,phosphates, iron,iron, potassiumpotassium and also inin vitamins.vitamins. In addition, the fibre content of brownbrown ricerice is much higher thanthan thatthat ofof whitewhite rice.rice.

Vitamins dodo notnot havehave anyany energyenergy value.value.

6. Water,water, which isis aa majormajor constituentconstituent ofof everyevery cellcell inin thethe body.body. Water isis indispensableindispensable forfor aa numbernumber ofof reasons:reasons: itit isis aa solvent,solvent, aa lubricant and a transporter of other nutrients and metabolic was ~~ products, as well asas assistingassisting inin regulatingregulating thethe bodybody temperature.temperature. It is recommended forfor adults toto consume 1 litre of water forfor every 4,180 kj (1,000(1,000 kcal)kcal) inin thethe diet.diet. Most of thisthis will be coveredcovered by the food which containscontains aa lotlot ofof water.water. The need for water is individual and is very dependent on the raterate of perspiration. Heavy physical work andand highhigh temperaturetemperature thereforetherefore considerablyconsiderably increaseincrease the need forfor water.water. This will be further discussed in sectionSection 3.1.1. "Climate"."Climate". - 36 -

Waterwater losseslosses shouldshould bebe replacedreplaced byby safesafe drinking water (boiled(boiled if necessary). Replacing moderate'moderate waterwater losseslosses partly by teatea andand coffee can be recommendedrecommended in cases when the water is not safe to drink without having beenbeen boiled.boiled. Liquids should be takentaken not only at meal times or when thirst is felt, but more frequently, as thirst underestimates thethe body'sbody's needneed forfor water.water.

7. AlcoholAlcohol.. Alcohol consumption isis harmful and should be strictly prohibited beforebefore or during workingworking hours.hours . Alcohol affectsaffects thethe functioning of the brain, decreases the speed of reaction and has aa tiring effect.effect. A personperson under thethe influenceinfluence of alcohol may cause accidents andand isis aa riskrisk toto him:-him- oror herselfherself asas wellwell as to workmatesworkmates.. Alcohol itselfitself has littlelittle nutritionalnutritional value,value, and also dehydrates the body.

It is important thatt hat the diet be varied and well-balanced so asas to prevent undernourishment (which(which meansmeans aa lessless thanthan optimaloptimal statestate of health and well-being and lack of energy resultingresulting from the consumptionconsumpti on of inadequate amounts of food),food ), and malnutrition,malnutrition, (which(which means a relative deficiencydeficiency oror excessexcess ofof oneone oror moremore nutrients).nutrients).

Undernourishment notnot onlyonly affects health and working efficiency, but may cause mental changeschanges as well,well, suchsuch asas depression coupledcoupled with a lack of drive and initiative.initiative.

Economic factorsfactors

There are many factorsfactors toto be considered when discussing measures for improving the nutritionalnutritional statusstatus ofof workers.workers. The first are the economic factors.

The worker'Sworker's wage can easily be compared with the cost of an adequate diet, calculated fromfrom thethe locallocal foodfood prices.prices. This will give an indicationindication as to whether the earnings are sufficient to cover the worker's and any dependentsdependents'' dailydaily diet.diet. However, thethe budgetbudget hashas alsoalso toto allowallow forfor otherother expenses suchsuch asas housing, clothes,clothes, schoolschool feesfees and transport.transport. Studies in developing countriescountries have shownshown casescases where workers inin thethe lowlow wage brackets, engaged inin heavy physical work, do notnot earn enoughenough toto provide an adequate diet, even forfor themselves.themselves. TheirTheir onlyonly possibilitypossibility toto keepkeep themselves fitfit forfor work isis forfor basicbasic foodstuffsfoodstuffs toto be grown by themthem or by their families.families.

In other cases,cases, nutritiousnutritious foodsfoods areare simplysimply notnot available.available. This is often the case forfor forestforest workers stayingstaying atat thethe worksite forfor a period of weeks or even longer.longer. They may be restrictedrestricted toto foodfood which can be stored safely inin the forest,forest, often inin aa hothot andand humidhumid climate,climate, without any storagestorage facilities. These may be rootcrops,rootcrops, maize and ricerice and other dried or canned foods.foods. This diet may be supplemented with whatever edibles the workers can findfind inin thethe forest,forest, suchsuch asas freshfresh roots,roots, fruit,fruit, nuts and, inin exceptional cases, birds, game oror fish.fish.

Whenwhen wage levelslevels areare insufficient,insufficient, thethe workers shouldshould bebe enabledenabled toto produce their own foodfood near thethe forestforest campcamp oror thethe village. Besides thethe provision of appropriate land,land, thethe working hourshours may also have toto be scheduled so as to allow sufficient timetime forfor thesethese activities.activities. - 37 -

Employers whowho have recognized the relationship between food and workwork efficiency have started workers' feeding prograrranesprogrammes and have established canteens or non-profit-making storesstores atat thethe workplace.workplace.

To provide, either freefree of charge or subsidized, a meal or substantial snack which is readyready to be eaten by the worker at or near the workplace, isis of course easier toto arrange inin concentrated large-scale forest operations than forfor workers scatteredscattered overover widewide areas.areas. A lotlot cancan bebe done, however, by very simple means, toto improveimprove the food situation also for isolated forest workers. This isis toto a great extent a matter of organization. Work can be scheduledscheduled and organized so as to allow timetime during working hours for one worker toto prepare an adequate meal forfor thethe rest of the group. An alternative isis toto hire a local person toto catercater forfor the group.group. Fresh andand variedvaried food can frequently bebe brought to the workplace byby thethe useuse ofof transporttransport suchsuch asas loglog trucks.trucks. When part of thethe food is provided by the employer it should cover not only the necessary energy intake, but should inin addition be composed in such a way thatthat all nutritional needsneeds areare met.met. BesidesBesides simplysimply providingproviding adequateadequate foodfood toto thethe workers, thethe objectiveobjective shouldshould bebe toto improveimprove eatingeating habits,habits, toto stimulatestimulate food production and to teach nutrition to the whole population. Forest enterprises, particularly inin remoteremote areas,areas, maymay alsoalso benefitbenefit fromfrom startingstarting agricultural andand aquacultural productionproduction forfor thethe feedingfeeding ofof workers.

Socio-culturalSocia-cultural factorsfactors

Apart fromfrom economic factorsfactors andand thethe availabilityavailability ofof food,food, socia-culturalsocio-cultural factors also have a major influence on eating habits. Food has symbolic values and cancan bebe used forfor expressingexpressing social,social, economic, emotional, religiousreligious andand culturalcultural relationships.relationships. The way toto select,select, prepare and consumeconsume foodfood depends toto aa greatgreat extentextent on thethe rolerole food plays inin aa givengiven situation.situation. The nutritional value of food isis obviously nil untiluntil itit isis eateneaten byby thethe worker.worker. It is therefore necessary to consider local habits when providingproviding foodfood or when teachingteaching nutrition,nutrition, soso that food is nutritional, but alsoalso acceptable and palatable fromfrom thethe worker's pointpoint ofof view.view.

Distribution ofof meals

The nutritional value ofof foodfood dependsdepends notnot onlyonly onon itsits compositioncomposition andand quantity, butbut onon thethe distributiondistribution ofof thethe mealsmeals asas well.well. Particularlyparticularly with heavy physicalphysical work requiringrequiring largelarge quantitiesquantities ofof food,food, itit willwill bebe necessary toto distribute thethe intakeintake overover preferablypreferably fourfour toto fivefive mealsmeals perper day, soso asas not toto disturb thethe digestivedigestive processes.processes. Ideally, at leastleast oneone quarter ofof thethe daily energyenergy requirementrequirement shouldshould bebe takentaken atat breakfast.breakfast. After each meal both thethe bloodblood sugarsugar levellevel andand thethe efficiencyefficiency ofof thethe muscles will increaseincrease sharply.sharply. It will thereafter fallfall steadilysteadily asas timetime passes. After threethree toto fourfour hourshours itit willwill reachreach aa veryvery lowlow level,level, whichwhich isis often accompanied by symptomssymptoms ofof fatigue.fatigue. If a small meal or a substantialsubstantial snack is taken every two hours thethe very low level will never be reached.reached. The worker will staystay onon aa higherhigher andand moremore eveneven levellevel ofof bloodblood sugarsugar andand efficiency throughoutthroughout thethe wholewhole day.day.

Analysis ofof accidentaccident recordsrecords andand humanhuman errorserrors havehave alsoalso shownshown aa distinct increasedincreased occurrence justjust beforebefore lunchlunch breaksbreaks andand atat thethe endend ofof the working day.day. If aa heavy meal is taken without allowing sufficient time to elapse afterwards for the digestive processes this will also leadlead to decreased efficiency.efficiency. - 38 -

Planning thethe distribution of food intake and restrest pauses is one very important measure toto preventprevent accidents.accidents. To distribute the food intakeintake over 5 meals per day (3(3 main meals and 2 snacks) is ideal for health and efficiency. Here also, local habits havehave toto bebe takentaken intointo consideration.consideration. But whatever thesethese habitshabits are,are, thethe worker shouldshould be encouraged to eat a substantial breakfast before work and never to work the whole day without at least oneone mealmeal break.break.

Apart fromfrom thethe nutritionalnutritional necessitynecessity ofof mealtimes, theythey alsoalso have a social value which shouldshould notnot bebe overlooked.overlooked.

When workers eateat onlyonly onceonce oror twicetwice perper day aa normal work output cannot be expected.expected. TheThe worstworst casecase isis whenwhen oneone mealmeal onlyonly perper dayday isis eaten,eaten, after work. Under suchsuch conditionsconditions physicalphysical workwork isis inadvisable.inadvisable.

2.5. Fatigue

Everybody will knowknow intuitivelyintuitively andand fromfrom experienceexperience what isis meant by fatigue. When describingdescribing oror tryingtrying toto definedefine fatiguefatigue itit isis possiblepossible toto make a very longlong listlist ofof differentdifferent typestypes ofof fatigue.fatigue. The chainsaw operator may think of fatiguefatigue inin termsterms of pain inin thethe back, arms and hands caused by static effort when handling a heavy chainsaw, by working inin a bent posture and by the effectseffects ofof vibration.vibration. The tractor driver may describe a feeling of general fatigue causedcaused by thethe noise, vibration and heat inin the cab, and the supervisor may be stressedstressed and tiredtired as a resultresult of tootoo many conflicting demands fromfrom chiefs,chiefs, colleagues and workers and of long hours of travelling onon dirtydirty roads.roads. The manager may have too great responsibilities or boring meetings, and thethe clerk may be mentally tired due to concentrated calculations,calculations, and the stress fromfrom knowingknowing that any errors he makes maymay havehave far-reachingfar-reaching consequences.consequences. Somebody may also be tired after a day with tootoo little or tootoo monotonous work, and so on.

A veryvery generalgeneral definitiondefinition ofof fatiguefatigue wouldwould bebe "weariness"weariness fromfrom bodilybodily or mental exertion".

In many casescases thethe feelingfeeling of fatiguefatigue isis toto be seenseen as a wholesome function and oneone way ofof thethe bodybody toto protectprotect itselfitself fromfrom overstrain.overstrain.

Provided one getsgets thethe needed rest,rest, itit cancan bebe aa ratherrather pleasant feeling to be tiredtired afterafter aa day'sday's work.work. To avoid an unhealthy accumulation of fatigue, it is necessary to allow forfor timetime to recoverrecover inin every 24-hour cycle. Most of thethe recoveryrecovery takestakes place during sleepsleep atat night.night. Short and longer rest pauses during the work day may also be necessary forfor maintaining thethe balancebalance betweenbetween restrest andand effort.effort.

Fatigue causescauses errorserrors andand accidentsaccidents atat thethe placesplaces ofof work.work. Many of these can be avoided if the workers are given sufficient restrest pauses, and if the workwork is planned and organized inin such a way as toto avoid an accumulation ofof fatigue.fatigue.

If fatigue isis accumulated over a longlong period due toto insufficientinsufficient daily rest,rest, thethe personperson will suffersuffer fromfrom chronicchronic fatigue.fatigue. This is very often accompained byby symptomssymptoms ofof illnessesillnesses suchsuch asas headachesheadaches andand digestive problems.problems. Mental instabilityinstability and liabilityliability toto depression areare otherother commoncommon consequences. Increased absenteeism and accident ratesrates will eventually be the result.result. - 3939 -

In Figure 19 examples are given of factors causing fatigue, symptoms of fatiguefatigue andana consequencesconsequences which may followfollow ifif a person does not get sufficient daily rest.rest.

Fatigue is a very complex phenomenon with no direct ways of measuring it. It is, however, possible to quantify it indirectly by measuring different indicatorsindicators of fatiguefatigue such as quantitative and qualitative performances, electrical activity inin thethe brain, and subjective feelingsfeelings of fatigue.

2.6. Rest Periods and SchedulingScheduling of Working Hours

If accidents, illnesses, discomfort and low efficiency caused by accumulated fatigue at work are to be prevented, there must be possibilities toto recoverrecover duringduring thethe day.day. There are several ways toto getget some of the necessary restrest apart fromfrom prescribing scheduled pauses of different lengthlength andand frequency.frequency. For example, when unavoidable staticstatic effort located in only a few muscles is the main reasonreason for being tired, the most efficient way to recoverrecover is not to sit down and simply do nothing but instead toto carrycarry outout somesome dynamicdynamic movements.movements. This will improveimprove thethe circulation of blood, which will redressredress the balance of oxygen and nutrients in the muscles and removeremove accumulated wwasteaste products. In this physically active way the recoveryrecovery will be faster compared to passive resting.resting. preferablyPreferably the work should be organized in such a way that a sufficient amount of dynamic efforts is a natural part of the work.

In other cases, whenwhen fatigue is caused by a physical overstraining ofof the entire body, a complete rest either sitting or lying down will be necessary.

Reasons forfor restrest pausespauses duringduring thethe day:day:

Pauses during the day are needed forfor a number of reasonsreasons of which the most importantimportant areare asas follows:follows: a) static work - to restore thethe balance in the muscles of oxygen and nutrients and to remove waste products, particularly lactic acid; b) heavy physical work - to recoverrecover respirationrespiration and circulation; toto restore energyenergy and to avoid a low level of blood sugar by spreading out the intake of food; also to removeremove lactic acid or pay thethe oxygen debt; c) standing work - to restorerestore the concentration of blood inin thethe legs and feet and decrease thethe bloodblood pressurepressure inin thethe veins;veins; d) work inin hot climateclimate - toto coolcool downdown thethe body,body, toto replacereplace waterwater losseslosses regularly; e) when exposed toto vibration - toto limitlimit exposureexposure time;time; f) when exposed toto high soundsound levelslevels -- toto getget restrest inin silencesilence (see(see forfor more details sectionsection 3.2.2.3.2.2. "Noise");"Noise"); 1

Examples of FACTORSFACTORS ExampExamplesl es of SYMPTOMS Examples ofof EFFECTSEFFECTS causingcausing fatiguefatigue of fatiguefatigue if worker isis depriveddeprived ofof restrest

A. Physical environment: temperature,temperature, Objective symptoms:symp toms: lighting, noise,noise, vibration,vibration, llocalocal muscular pain

elevation,e l eva tion, lacklack ofof oxygenoxygen . lack of or impairedi mp aired attention, perception and alertnessa l ertness Effects:

. increased reaction timetime . errors Physical and . mentalmental workload: . visvisualual fatiguefatigue accidents InIncreased:creased: static work, heavyheavy physical work,work, . yawningyawn ing chronic fatiguefatigue Absenteeism andand monotonous work, socially isolatedisolated LabLabourour Turnover work'work,, concentratedconcentrated mentalmental work,work, --P work overstrainingove r st r aining thethe eyes SymEtomsSymptoms of chronicc hroni c Subjective symptoms:symptoms: fatigue: to feel:feel: unwillingness to work - bored depression C. Nutrition: undernourishment, - unwilling toto makemake anyany iillnesses,l lnesses, suchsuch as:as: ~ deficiency of water, alcoholalcohol kind of efforteffort - headaches cocomsumption,msumption, digestive processes - postural discomfortdiscomfort - stomachstomach painspains after foodfood intakeintake weary - heartheart problems - drowsy reduced resistance - sleepy to disease in general - irritatedirritated D. Health:Hea lth: disdiseases,eases, fever,fever, pains,pains, handicaps

E. Psychological troubles:troubles: anxiety,anxiety, confconflicts,licts, obligationsobligat i ons

F. CCircadianircadi an rhythm:rhythm: nightnigh t and sshifthift work

Figure 19. Diagram of examples of factors causing fatigue, symptomssymptoms ofof fatiguefatigue anda nd effectseffects whichwhich will eventually resultresult fromfrom insufficientinsufficient rest.rest. - 41 - g) repetitive and boring work - toto breakbreak monotony;monotony; h) isolated work - toto provide forfor socialsocial contacts;contacts; i) dangerous work -- toto preventprevent accidentsaccidents causedcaused byby fatigue.fatigue.

Studiesstudies have shown that it makes good economic sense to take well-planned restrest pauses, as theythey have a positive effect on performance. The improvedimproved performance will compensate more thanthan enough forfor thethe lost working time.time.

Different kinds ofof restrest pauses Generally speaking,speaking, itit isis preferable toto letlet thethe workers controlcontrol thethe workpace themselves soso thatthat theythey can take _Ea!uEa.!natural _ _ _ pa~s~spauses_ _ when theythey feel the need.

It is particularly advantageous if the worker can freely change to other activities, suchsuch as maintenance of toolstools and machines, or consulting with workmates andand supervisors.supervisors. The worker can inin such cases carry out this kind of lightlisht activity when in need of a lightlight rest,rest, as an alternative to ceasing wóikwork entirely.entIrelY.- "A change of work isis oftenoften asas goodgood asas aa rest"rest" isis a generally acceptedaccepted truth.truth. For oldold workers,workers, whowho have impaired capabilities to cope with peaks in the physical workload, the freedom of controlling their own pauses and workpace can be decisive whether they will be able to gogo onon with theirtheir jobs.jobs. IfIf thethe workwork includesincludes veryvery heavyheavy elements,elements, e.ge.g.. carrying of logs, the work should be organized in such a way that continuous duration of such elements isis as short as possible, and lighter work isis done inin between,between, soso thethe peak ofof strainstrain isis keptkept lowerlower andand thethe needneed for recovery also.also.

Veryvery oftenoften thethe workersworkers getget opportunitiesopportunities toto restrest duringduring thethe dayday because of thethe nature ofof thethe work, itsits organization,organization, oror ratherrather lacklack ofof organization. A machine breakdown may, forfor example, lead to long periods of passively waiting forfor thethe arrival ofof sparespare partsparts andand thethe repairer,repairer, and the repairrepai r work toto bebe done.done. These types of ~rk=iEf.!u~n~edwork-influenced pa~s~spauses may, or may not,not, bebe anan efficient efficient way way of of resting, resting, dep6-énaiEg-oTa depenoing on whetnerTati ther they Thy occuroccur at the moment the worker needsneeds aa restrest oror not.not.

When itit isis neitherneither possiblepossible toto taketake naturalnatural pausespauses nornor toto restrest byby doing light work andand alsoalso no work-influenced pausespauses cancan be expected,expected, thenthen the managementmanagement should have prescribed scheduled restrest pausespauses.. The length and frequencyfrequency of of these these pauses-wili pauses-wIll 3efoerid-ori oePend-on -6a number oroT ractorsTactors such as physical workload, climaticclimatic conditions,conditions, workers' nutrionalnutrional status,status, physicalphysical fifitness tness and age, andand thethe lengthlength ofof thethe workingworking day.day. Scheduling of restrest pauses

Generally, thethe firstfirst partpart ofof anyany restrest pausepause isis farfar more efficientefficient inin terms of recuperationrecuperation thanthan thethe latterlatter part.part. Therefore, takingtaking many shortshort pauses is a more effficient way of preventing anan accumulationaccumulation ofof fatiguefatigue compared to a fewfew but longer pauses - eveneven when thethe lengthlength ofof thethe shortshort pauses taken together isis thethe same as thethe longlong pause.pause. Many investigationsinvestigations have shown that restrest pauses tendtend to increaseincrease outputoutput ratherrather thanthan toto decreasedecrease it. - 4242 -

If 50 percent ofof aa person'sperson's maximalmaximal workingworking capacitycapacity isis required,required, which isis common inin heavy physical work in forestry,forestry, thethe time needed for rest will be about 2020 percentpercent ofof thethe totaltotal workingworking time.time. This means thatthat aa break of aboutabout tenten minutesminutes perper hourhour shouldshould bebe provided.provided. If the work isis lighter the pauses will bebe shortershorter oror lessless frequent.frequent. If the work requiresrequires about 75 percent of thethe worker's maximal capacity (which(which is extremely heavy work), thethe timetime forfor restrest pausespauses hashas toto increaseincrease toto 6060 percent.percent. To solvesolve the problem of heavy physical work and poor workingworking conditions by means ofof extra long or frequentfrequent restrest pausespauses shouldshould alwaysalways bebe thethe lastlast wayway out.out. Considering that restrest pauses more often than not are unproductive, it will be more efficient to change thethe work so as to reducereduce the needs for restrest pauses to thethe minimum.

Even when the work isis lightlight andand comfortablecomfortable therethere will,will, however,however, always be a need for shorter breaks, as no work posture is so perfect that it is possible to remain the same during long periods of time withoutwithout increasing discomfort. Even during sleep a changechange ofof postureposture isis needed,needed, and more frequentlyfrequently ifif thethe bedbed isis uncomfortable.uncomfortable.

For an eight-hour working day it is also advisable to have a longer break ofof aboutabout 1515 minutes minutes in in the the morning, morning, and and often often also also in thein theafte-rn-cicii. afternoon. Pir-Eicularlyparticularly ifif thethe workwork isis heavyheavy there willwill be a need toto spreadspread outout thethe intake of food over the day so as to avoid overloading the digestive organs with onlyonly oneone heavyheavy meal.meal .

An additional meal break of about three quarters of an hour or an hour shouldshould also also be be iimravidd-7. provIded-:­ It is necessary to allow forfor about 1515 minutes toto elapse afterafter eatingeating aa moremore substantialsubstantial mealmeal forfor thethe digestivedigestive processes.

If the workwork is physically heavy or dangerous or the worker is old or unfit, some scheduledscheduled pausespauses areare essential.essential. There isis otherwiseotherwise aa risk,risk, when the pauses are only optional, thatthat the workers may decide to work throughout the day without stopping,stopping, to be able toto leave work earlier. Whenwhen work isis paidpaid onon aa piece-ratepiece-rate agreement,agreement, thethe workersworkers maymay putput inin longlong hours without sufficientsufficient breaks.breaks. This will lead toto accumulated fatigue,fatigue, low efficiency and increasedincreased accident rates.rates. Physically heavy work inin a hot climate requires special considerationsconsiderations which are discussed furtherfurther inin Section 3.1.1 Climate. Working hours per day

It is a common mistake to believe that there is a linear relationshiprelationship between work output and thethe length of the working day, as isis illustratedillustrated in Figure 20, curvecurve A.A. ExperienceExperience has shown that after somesome hourshours thethe outputoutput pe~ourper hour will start to fall,fall, illustratedillustrated by curvecurve B. In many casescases thethe output per hour is lower throughoutthroughout the day, because thethe worker will automatically adjust toto aa lowerlower workwork pace.pace. This is often necessary toto prevent overstraining because of lack of energy, illustratedillustrated by curve C. - 4343 -

WORK OUTPUTOUTPuT

A

B ~--

c

1

Figure 20. The relationrelation between the number of working hours and work output. A. indicatesindicates a linearlinear relation,relation, which is an unrealistic assumption.assumption. B. and C. indicateindicate whatwhat happenshappens under actualactual workingworking conditions.conditions.

Instead of frequently calling for overtime work, it would be more efficient to employ additionaladditional workers.workers. Another reasonreason forfor avoiding excessive overtime is that it leads to higher absenteeism caused by illness and accidents.

Workingworking days per week andand annualannual leaveleave Similar effects as have been described above have also been shownshown when changingchanging thethe numbernumber ofof working days.days. At leastleast one restrest day per week should be provided, not only for reasonsreasons relatedrelated to safety, health and efficiency, but alsoalso forfor socialsocial reasons.reasons. The same reasonsreasons hold goodgood forfor the need for some annualannual leave.leave. It should therefore be a policy toto avoidavoid payment forfor leaveleave which hashas notnot been takentaken byby thethe worker.worker.

Night or shift work

Night oror shiftshift work isis veryvery unusualunusual inin forestforest operationsoperations inin developing countries.countries. It is more common inin wood industries.industries.

Night andand shiftshift workersworkers usuallyusually complaincomplain ofof disturbeddisturbed sleepsleep duringduring the daytime. partlyPartly this is attributed to noise, which is usually greater during thethe day thanthan atat night.night. Other factors,factors, accordingaccording toto manymany workers,workers, are the feelings ofof restlessnessrestlessness when tryingtrying toto sleepsleep duringduring thethe daytime,daytime, and that daytime sleepsleep isis notnot refreshingrefreshing enough.enough. It has been shown that on average, daytime sleepsleep isis distinctly shortershorter thanthan night-timenight-time sleep.sleep. Most night and shift workers will, therefore,therefore, suffersuffer fromfrom anan accumulatedaccumulated deficiency of sleepsleep oror "sleep"sleep debt". The quality of daytime sleep isis also impaired. - 4444 --

Both mental and physiological functions such as weariness,weariness, production of adrenalin (a(a hormone which isis sometimessometimes called "stress hormone"), heart rate, blood pressure, respiratoryrespiratory volume,volume, bodybody temperaturetemperature andand digestion,digestion, show characteristic fluctuationsfluctuations overover aa 24-hour24-hour cycle.cycle. This isis calledcalled thethe circadian rhythm.rhythm. According to thethe circadiancircadian rhythmrhythm thethe readinessreadiness for work isis at its peak during thethe forenoonforenoon andand afternoon.afternoon. Thereafter, it becomes poorer andand declines even more at night,night, eventually reachingreaching its lowest point in the early morning hours (between(between 22 andand 44 o'clock).o'clock).

Lower productivity and more frequent accidents and errors are consequences toto be expectedexpected duringduring nightnight work.work. The conditions surroundingsurrounding the workeworkerr at night are, however,however, usually so different from daytime conditions that any comparisoncompar ison of performance and accidents must be made with reservations.reservations. Examples of factors whichwhich often varyvary considerably between night and day are the number of people at work (fewer(fewer at night); workpace (slower(slower at night);night); work taskstasks (many(many dangerous jobsjobs suchsuch as maintenance and repairrepair areare onlyonly carriedcarried outout inin thethe daytime); and supervision (fewer(fewer supervisorssupervisors atat night).night). These are factors which of course have a significant impact on efficiency and safetysafety,, and may cocoverver upup ill effects of disturbeddisturbed bodybody rhythmsrhythms amongamong thethe workers.workers.

It is wellwell known tthathat night and shift workers commoncommonlyl y suffer from bad health.health. Many have toto givegive upup shiftshift workwork forfor thisthis reason.reason. workersWorkers who remain on night shift can,can, therefore,therefore, bebe regardedregarded asas aa "positive"positive selection"selection" of those having good healthhealth andand greatgreat adaptability.adaptability. Due to lack of other job alternatives or because night work provides monetary incentives, many workers on night shiftshift secretlysecretly suffersuffer fromfrom bad health.health.

Common ailments among night and shift workers are ulcers, nervous disorders, stomachstomach troubles, intestinalintestinal disorders and chronic fatigue.fatigue.

Over a period of years, people do not usually become accustomed to night work, but, on thethe contrary,contrary, theythey become increasinglyincreasingly liableliable toto different diseases.diseases. Older workers with no previous experience of night and shift work should not bebe engagedengaged inin suchsuch work.work .

Closely related to physical health isis social well-being. In many cases, complaints among shift and night workers regarding problems related to their social life are even more frequent than those regarding physical health. These problems mainly concern familyfamily life, child care, social isolation from friends and relatives, and limited or no participation in group activities.activities.

Night and shiftshift work shouldshould alwaysalways bebe avoidedavoided whenever possible.possible. If unavoidable, a great effort shouldshould be made toto minimize thethe disadvantages itit imposes upon the workers.

2.7 Mental Workload andand Stressstress

Stress can be defined as "the"the state of physiological and mental arousal, which is caused by an imbalanceimbalance between perceivedperceived environmental demands, and the individual's perceived capacitycapacity toto meet thosethose demands".demands". Stress, then, occurs when an individualindividual becomesbecomes badly matched toto thethe envienvironment. ronment. -45-- 45 -

Both psychological and physiological functions are affected by stress. Examples ofof "direct""direct" measures of stressstress are heart rate,rate, heart raterate variability, levels of adrenalin and noradrenalin ("stress("stress hormones") in the blood or inin thethe urine.urine. Disturbances of some of the functions may lead to psychosomatic disease (physical(physical disease which has a mental origin), and heart and blood vessel diseases.diseases.

Stress factors (stressors)(stressors) In any job,job, there are a large number of environmental sources of stress such as the characteristics of the job itself, interpersonal relationships at work, the role of the worker in the workplace (e.g.(e.g. as a supervisor), "climate" and structure of the workwork organization, and problems associated with thethe contacts between the organization and thethe outside world (e.g. workingworking in a logging company which has poorpoor relationsrelations withwith thethe locallocal population may causecause stress).stress).

In the following section, attention will be focussed on stressors related to thethe jobjob itself.itself. Examples of job-related stressors are to have too muchmuch oror too little work, time pressure and deadlines, too many or difficult decisions toto make; fatiguefatigue from physical strainstrain and from physical factors in the workwork environment such as noise, excessive travel, long working hours, copingcoping withwith changeschanges atat work, andand costscosts ofof makingmaking mistakesmistakes (monetary or dismissal).

Where therethere hashas beenbeen increasingincreasing mechanizationmechanization andand automationautomation inin forest industries, as well as the tendencytendency to divide a jobjob task into as many simple and limitedlimited operationsoperations asas possible,possible, jobsjobs havehave becomebecome narrow,narrow, specialized and repetitive.repetitive. In forest operations suchsuch as fellingfelling andand transport this is not so much of a problem as inin the wood-processing industries such as , veneer and plywood plants or pulp and paper mills.

The content of jobsjobs inin thethe latterlatter industriesindustries isis often prescribed inin detail and allowsallows littlelittle discretion.discretion. Sometimes the worker carries out only a single operation on a small part of the total end product, and at a pace predetermined by thethe speedspeed ofof aa conveyerconveyer belt.belt. Consequently,Consequently, thisthis givesgives thethe worker little or no controlcontrol overover howhow thethe tasktask isis performed.performed. TheThe jobjob hashas become monotonous andand repetitive.repetitive.

Both field studies and laboratorylaboratory experiments havehave shownshown thatthat monotonous and repetitiverepetitive work underunder industrialindustrial conditionsconditions produceproduce badbad physiological and psychological symptoms.symptoms. A studystudy fromfrom aa sawmillsawmill demonstrated thatthat a group ofof sawmillsawmill workers whowho hadhad jobsjobs whichwhich were monotonousmonotonQUS and repetitive,repetitive, butbut atat thethe samesame timetime demandingdemanding muchmuch responsibility,responsibili ty, secreted much more adrenalin (a(a "stress-"stress- hormone") than other groups ofof sawmillsawmill workers.workers. The workers also had a higher incidence of psychosomatic disease andand moremore absenteeism.absenteeism.

under-utilizedUnder-utilized physicalphysical andand mentalmental capacitiescapacities characterizecharacterize aa statestate which is called "underload","underload", while "overload""overload" meansmeans havinghaving tootoo muchmuch toto dodo or doingdoing a job which is too difficult (quantitative(quantitative or qualitative overload). Both underload andand overloadoverload situationssituations relaterelate toto stressstress symptoms. On the other hand aa moderate workload, which isis when thethe demands of the jobjob most closely match thethe capabilitiescapabilities ofof thethe worker,worker, will givegive thethe least stress and thethe highesthighest efficiency.efficiency. -- 4646 --

2.8 Individual Characteristics ofof thethe Worker

In the description inin previous sectionssections ofof thethe differentdifferent aspectsaspects ofof the worker and the work, the workers have sometimes been referred to without consideringconsidering individualindividual differencesdifferences inin theirtheir capabilities and limitations. In this section, somesome ofof thethe mostmost importantimportant individualindividual characteristics ofof thethe workersworkers willwill bebe discussed,discussed, namely:namely: age,age, bodybody size,size, and sex.sex.

A. Age

Age affectsaffects aa numbernumber ofof factorsfactors ofof importanceimportance forfor bothboth thethe physicalphysical and mental workingworking capacity.capacity.

Old personspersons

Some aspects of the working capacity decrease progressively with age due to:to:

a lower maximalmaximal oxygenoxygen intakeintake oror aerobicaerobic capacity;capacity;

a decreased massmass ofof muscles.muscles. The peak for muscular power inin both men and women isis reachedreached betweenbetween thethe age of 2525 and 3535 years. Older people havehave considerablyconsiderably lowerlower muscularmuscular power.power.

a decreased adaptabilityadaptability toto environmentalenvironmental heat;heat;

a decreased adaptabilityadaptability toto changedchanged sleepingsleeping pattern;pattern;

impaired eyesight due to: a) less elasticity of the lens leading to impaired accommodation of the eye; b)b) needneed for aa higher lighting level;

an impaired hearing capacity, particularly the hearing of high frequencies; an impaired speed of mental operations and reaction time because the reflexes need a longer timetime toto passpass throughthrough thethe nerves;nerves;

an impaired capacity to remember over a longer time what is recently learned. There is, however, only a small reduction, if any, in the capacitycapacity forfor immediateimmediate memorization.memorization.

All thesethese may appear asas aa depressingdepressing picture,picture, butbut therethere areare redeemingredeeming features as well. The amount and variety of experience and memories will increase with age.age. In manymany situations this willwill compensate for the declined physical and mental capacity.capacity. Older people may for some time therefore be able toto maintain thethe samesame performanceperformance asas youngyoung people.people. Some people also age physically and mentally slowerslower thanthan thethe average.

TheThe dayday willwill come, however,however, whenwhen the physical workingworking capacity has declined to a level at which no heavy work shouldshould be done. The old worker should then preferably be transferred to a job which is physically light but still requiresrequires experience.experience. The old worker can for instance provide experienceexperience and some degree of leadership and stability to groups of younger workers. - 47 -

To transfer an old worker to a job withwith the task of handling a new machine may not be advisable ifif thethe worker has no previous experience of machines, even ifif thethe rationalerationale isis to provide a physically lighter job.job. The old worker may encounter difficulties in learning how to operate the machine safelysafely andand properly.properly.

It is further very important for older workers to have the freedom to work in their individual rhythmrhythm and taketake pauses when needed. The peaks of physical workload should be avoided, as they may be the decisive reasonreason why the old worker cannotcannot staystay onon thethe job.job.

In most western countries the age of about 40-50 years is regarded as the age at which thethe workingworking capacitycapacity startsstarts toto decline.decline. For many workers in developing countries, who suffersuffer from undernutrition, disease and a hot climate, this stagestage maymay bebe reachedreached muchmuch earlier.earlier.

Recuperation timetime after diseases and accidents isis also longer forfor an old person compared toto aa youngyoung one.one.

Young persons

very young persons also callcall forfor specialspecial attention inin their working life. Most countries have lawslaws andand standardsstandards regulatingregulating thethe minimum age for employment inin industry.industry. The age of 15 is a commonconunon minimum requirement for industrial employment, with a stricter requirement for the age of 18 if the work is physically heavy, dangerous, or involves the operation of machines. Additional standardsstandards regulcting,regul~ting, for example, thethe maximum number of working hours per day or week, shift or night work, or maximum weight to be lifted and carried, alsoalso existexist inin severalseveral countries.countries. The rationale for this special treatment of adolescents is to protect the young worker from occupational diseases andand accidents.accidents. To overstrain thethe body before it isis fully grown by doing heavy physical work may cause permanent injuries. The back inin particular shouldshould bebe sparedspared fromfrom harmful liftinglifting andand carryingcarrying ofof heavy loads.loads.

It takes time to develop strength, skill and experience and it must be accepted thatthat during thisthis timetime thethe youngyoung worker cannotcannot produceproduce thethe samesame as an experienced and skilledskilled adultadult worker.worker.

Young workers should not be put under production pressure as theythey may take risks which can cause accidents, due to lack of experience and skill. They should be given extra closeclose guidanceguidance andand supervisionsupervision when trainingtraining forfor any jobjob involvinginvolving risks.risks.

To enforce strict lawslaws andand standardsstandards forfor thethe young workers andand toto give a thorough introduction to the job,job, with much emphasis on safety aspects and working techniques,techniques, isis aa wise policy which will paypay well.

Young workers need much guidance and understanding which inin many cases can be provided by mixing older and young workers inin the samesame crew.

B. Body size

The problems relatedrelated toto differences inin body sizesize betweenbetween races,races, sexessexes and individuals when designing workplaces, tools and machines have already been mentioned in Section 2.3. "Work"Work Postures". - 4848 -

There is some evidence from limited studies in a few countries that there is a close relationshiprelationship between body weight and the capacity to carry out heavy physicalphysical work.work. An earlyearly studystudy carriedcarried out inin IndiaIndia (1966)(1966) gives an example of thisthis relationshiprelationship by showingshowing thatthat a group of IndianIndian forest workers, whose weight was only about 70%70% of Scandinavian forestforest workers' weight, had a performance of muscular work which was correspondingly also about 65% of what thethe Scandinavian workers could perform.

Most literatureliterature and researchresearch reportsreports onon ergonomics are fromfrom studiesstudies carried out onon peoplepeople fromfrom westernwestern countries.countries. When referringreferring toto "the"the average worker" inin thesethese studies thisthis usually means a male worker, about 25-30 years old,old, andand withwith aa bodybody weightweight ofof 6565 kg.kg. As the average body weight is, in general, lower in many developing countries, resultsresults from western countriescountries areare notnot alwaysalways applicableapplicable toto workers fromfrom otherother partsparts ofof the world. c.C. Sex

In westernwestern countries the average woman has a 25% lower body weight than the average man.man. Her physical working capacity is correspondingly 25-30% lower.lower. In many developing countries thisthis relationshiprelationship is,is, however,however, not the same.same. Many countries have specialspecial lawslaws forfor thethe employment of women inin industry. In particular, special attention should be given to women who are pregnant oror areare breastbreast feeding.feeding. They must not be exposed toto harmfulharmful chemicals, air pollution, night work, heavy physical work, or liftinglifting and carrying of heavyheavy burdens.burdens. Women with smallsmall childrenchildren maymay oftenoften needneed special working hourshours andand arrangementsarrangements forfor childchild care.care.

There are many examples of specialspecial laws,laws, arrangementsarrangements andand standardsstandards said to be for the protection of women in general being abrogated under conditions when the women are needed to maintain industrial production, for example, during or justjust after a war which occupiesoccupies thethe men.men. When thethe lawslaws are introduced again they may serve more as a tool to keep women outout ofof thethe better-paid jobsjobs inin industry.industry.

In general, workingworking conditions which are unhealthy and dangerous for the female worker are equally bad for the male worker. The goal should therefore be to improve working conditions so as to fit as many persons as possible whether theythey areare men, women, young,young, old,old, largelarge oror small.small.

2.9 Socio-cultural Aspects

In most of what has been said soso farfar thethe ideaidea has been thatthat all human beings have similarsimilar basicbasic needs, requirementsrequirements andand limitations.limitations. In the last section (2.8)(2.8) mention was made of some of thethe factorsfactors which, inin spitespite of all the similarities, make itit necessary toto givegive specialspecial considerationconsideration toto certain groups of workers, such as old workers, pregnant women, and very young workers.

Other aspects which often also have toto be considered are thethe socio-cultural and economiceconomic aspects.aspects. For example, habits, beliefs, traditions, religions and socio-economic conditions may differ fromfrom one area to another inin one and thethe samesame country.country. Individual workers or small groups of workers may have a divergent socio-culturalsocio-cultural background.background. In many - 4949 - cases this will not causecause anyany particularparticular problemsproblems atat thethe placeplace ofof work.work. In other cases,cases, itit may be necessarynecessary toto pay much attention toto thethe consequencesconsequences at thethe planning stagestage ofof anyany kindkind ofof forestforest operation.operation. The list of examples could be very long,long, butbut mention will be made only of a fewfew with direct ergonomicergonomic implications.implications.

It is not unusualunusual that the forest workerworker is bothboth a wagewage earner andand the cultivator of a smallsmall piecepiece ofof land.land. The combination ofof gettinggetting somesome food at little expense from private agricultural work, and some necessary cash as a wage earner might very well be the optimal way of survival. If eight hours per day of regularregular work .inin the forestforest isis introducedintroduced inin thisthis kind of society, itit may interfereinterfere with the farmingfarming activities. The workers may then have to buy more, or all,all, ofof thethe needed foodstuffsfoodstuffs at thethe market. This might affect thethe nutritional intakeintake of both the workers and theirtheir familiesfamilies..

Another example, which alsoalso hashas toto dodo with nutrition, isis different eating habits.habits. workers may have thethe habit of takingtaking only a cupcup of coffeecoffee or tea inin thethe morning, before work, and waiting until evening forfor thethe main meal. As aa consequence,consequence, theirtheir capabilitycapability toto carrycarry out heavy physicalphysical work in the forest will be noticeablynoticeably impaired.impaired. Their productivity, safety and health will suffer.suffer. It should then be a task for the employer to influence the workers toto adoptadopt betterbetter eatingeating habits.habits. A solution might be thethe provision of a free meal during thethe firstfirst half of the working day. This would bebe aa veryvery goodgood investmentinvestment inin manymany developingdeveloping countriescountries regardlessregardless ofof what kindkind ofof eatingeating habitshabits thethe workersworkers have.have.

Other habits may be difficult oror impossibleimpossible toto influence.influence. For example, those habits which are based on religiousreligious beliefs, suchsuch as longlong periods of fasting, or the refusalrefusal toto removeremove a very special headgear inin order to wear aa safetysafety helmet.helmet.

Often thethe cultural values areare notnot soso explicitexplicit as inin thethe examplesexamples mentioned above.above. This can be illustratedillustrated by thethe followingfollowing quotation regarding the interplay of cultural values among Filipino workers: "Values like utang-na-loob (debt(debt of gratitude) to theirtheir employer, thethe strongstrong kinship system or family ties and thethe bahala-na (come-what-may(come-what-may or faith-in-God) attitude might explain whyWhy thethe workers are contented with their working and livingliving conditions".conditions". (Operational efficiency, work studystudy and ergonomics inin forestry.forestry. ILO, 1986).

It is beyond the scope of this publication to elaborate the unlimited socio-cultural aspects which have toto be considered inin forestforest management inin various societiessocieties around thethe world.world. The message is rather to rememberremember the importance of the socio-cultural and economic aspects inin general. They may play thethe decisive rolerole inin whether aa projectproject becomesbecomes aa failurefailure oror aa success.success. - 50 -

3. WORKINGOORKING ENVIRONMENT

3.1 Biological andand Physical FactorsFactors

3.1.1. Climate

Most forestryforestry work isis done out of doors, with very limited possibilities ofof protectingprotecting oneselfoneself againstagainst thethe weather.weather. From an ergonomic point of view the most important climatic factors are: extreme temperatures; high relativerelative humidity; strong wind, heavy rain and snow. When?hen oneone hashas toto workwork underunder unfavourableunfavourable climaticclimatic conditionsconditions it cannot be expected that the same performance will be reachedreached as when the working environmentenvironment isis optimal.optimal. To cease work, or adjust working methods, when thethe wind is too strong or the rainfallrainfall tootoo heavy,heavy, soso asas toto allowallow thethe work toto bebe carriedcarried out safelysafely is often more readilyreadily accepted than to take the same precautions because of extreme temperaturestemperatures andand humidity.humidity.

Hot climate Normally itit isis easiereasier toto preventprevent discomfortdiscomfort arisingar1s1ng fromfrom lowlow thanthan from high temperatures. The hot, or hot and humid, climate creates the biggest climaticclimatic problemsproblems inin many developing countriescountries andand will therefore be given moremore spacespace inin thisthis presentationpresentation thanthan thethe coldcold climate.climate.

Generally, thethe severe stress on the body causedcaused by heat is overlooked, particularlyparticularly when combinedcombined with humidity.humidity. This isis most probably due toto aa lacklack ofof knowledgeknowledge regardingregarding thethe hazardoushazardous effects of heat stress. Heat stress isis not only a problem forfor forestforest workers inin a hot climate but forfor forestforest firefire fightersfighters asas well.well.

Withwith somesome knowledgeknowledge ofof thethe internalinternal heatheat production,production, howhow thethe heatheat balance inin thethe human body isis controlled,controlled, andand howhow man isis affectedaffected by thethe climate, preventive measures couldcould bebe takentaken soso asas toto provideprovide somesome protection indirectly.indirectly. These measures could be of different types, such as adjustment of thethe working timetime schedule,schedule, workingworking methods,methods, clothing,clothing, availability ofof drinkingdrinking waterwater andand shelter.shelter.

In Section 2.2. "Energy"Energy Requirements and PhysicalPhysical Workload" the mechanisms which regulateregulate thethe bodybody temperaturetemperature werewere discussed,discussed, particularlyparticularly the importanceimportance ofof sweating.sweating. A commoncommon problem inin thethe tropicstropics isis thatthat when the relative humidity ofof thethe airair isis high,high, lessless sweatsweat cancan evaporateevaporate andand thethe cooling effect will thereforetherefore bebe impaired.impaired.

Another importantimportant factorfactor toto consider,consider, besidesbesides temperaturetemperature andand humidity of thethe air, isis air velocity. In a hot and humid environment airair movements will increaseincrease thethe evaporationevaporation ofof sweat.sweat. If the air temperature is lower than the temperature of the skin, the wind will also cool the skin by convection, and therebythereby reducereduce thethe amountamount ofof sweating.sweating. - 51 -

Air temperaturete~rature affectsaffects convection.convection. TheThe easiesteasiest wayway toto measuremeasure airair leipre--r-ata-&temperature Is- Is-withwith an anordinary ordinary thermometer, thermometer, which, which, however, however, shouldshould bebe screened if placed nearnear anyany radiation.radiation. Digital and electronic thermometersthermometers are also available.available.

Air humidity.humidity. HighHigh airair humidityhumidity reducesreduces thethe evaporationevaporation ofof sweatsweat andand thusthus -Ccas-EiTiffeiconstitutes a thermal stress forfor the worker.worker. It can be measured with a psychrometer. A psychrometer consists of twotwo thermometers and a device to ensure ventilation of thethe thermometersthermometers at a minimum air velocity. The first thermometer isis an ordinary one measuring the "dry""dry" temperature. The other thermometer isis surroundedsurrounded by a wet wick, generally made from muslin, and gives thethe "wet""wet" temperature.temperature. The difference betweenbetween bothboth thermometersthermometers is determinant forfor thethe humidity.humidity.

Air velocity affectsaffects bothboth convectionconvection andand evaporation.evaporation. It is usually measured-wIthite-isTard-with anan anemometer.anemometer. Air velocityvelocity isis generallygenerally difficult toto measure because ofof itsits rapidrapid fluctuctionsfluctuctions inin intensityintensity andand direction inin time.

Radiant temperaturetemperature isis aa resultresult ofof thethe differencesdifferences inin surfacesurface temperaturetemperature eetweenbetween Wa-c-eiit-safaces.adJacent-surfaces. It can be measured with a blackblack globeglobe thermometer, which is an ordinary thermometer placed in the centre of a black globeglobe mademade ofof thinthin copper.copper.

Climate indexindex

There have been many attempts to solve the problem of how best to combine thethe measurements ofof thethe different variables mentioned above,above, aimingaiming at having only one figurefigure forfor indicatingindicating thethe actualactual strainstrain any particularparticular combination hashas onon thethe humanhuman body.body.

oneOne of thethe most generallygenerally acceptedaccepted ofof manymany existingexisting indicesindices isis thethe WBGT (wet(wet bulb-globebulb-globe temperature)temperature) index.index. What most indices fail toto consider is thethe metabolic raterate of thethe human being.

Work

Whenwhen thethe climate isis very unfavourable (hot,(hot, humid,humid, lowlow airair velocity)velocity) and/or the work is tootoo heavy forfor thethe body toto dissipate thethe excess heat,heat, thethe heart raterate will increase and eventually thethe body temperaturetemperature will rise.rise.

In Table 3 below a simplified example illustrates how air temperature and air humidity affect the working capacity. - 52 -

Table 3.3. Relation between work capacity, air temperaturetemperature and air humidity.humidity.

AirAir AAirir WorkWo rk capacitycapac ity hhumidityumid i t y ttemperatureempera ture overover resting levelleve l

o 11007.00% 25oC2s e (77oF)(7 7° F) 17 kJkJ/min/ min (4 kcal/min)kcal / min) 0 11007.00% 330oC0 e (86oF)(86° F) 6 kJ/min ((1.51.5 kcal/min)kc al / min)

11000/,00% 335°Csoe (95°F)(9SoF) 0 kJ/minkJ/ min

Source: Guide to Safety andand HealthHealth inin ForestryForestry Work,Work, ILO,ILO, Geneva.Geneva. Fourth ImpressionImpression 1979.1979 .

As shownshown inin thethe tablet able itit isis possiblepossible toto performperform quitequite heavyheavy work when thstho temperature isis aboutabout 250C250 C andand thethe humidityhumidity reachesreaches 100100 perper cent.cent. At 35 CC andand the same humidithumidity,y, the body cannot dissipate any more excessive heat than what isis producedproduced whenwhen resting.resting. The alternative will be an accumulation of heatheat inin thet he body.body.

Most people will startstart feelingfeeling sick when thethe body temperaturetemperature risesrises and will automatically slow down their work pace. The lower work intensity which can sometimessometimes bebe seenseen inin countriescountries with aa hothot climateclimate isis thusthus not a sign of laziness, but a physiologically reasonablereasonable way to cope with the strain.

If this werewere not done the temperature would continue to rise until it could no longer be controlled and the person would collapse. When discussing workload itit isis thereforetherefore necessarynecessary notnot onlyonly toto discuss energyenergy expenditure, but alsoalso toto taketake thethe climateclimate intointo account.account.

Replacement of water losses

When sweating,sweating, thethe bodybody willwill loselose considerableconsiderable volumesvolumes ofof water. TheThe water has toto be replacedreplaced continuouslycontinuously soso asas notnot toto causecause dehydrationdehydration of thethe body. The concentration ofof saltsalt inin thethe bodybody regulatesregulates ourour thirst.thirst. Thirst, however, may be insufficientinsufficient toto covercover thethe losseslosses ofof liquid,liquid, especiallyespecially inin heavy work.

Inadequate replacementreplacement of water can be discovered by simplysimply checking for weight losses.losses. A reducedreduced weightweight ofof 1-21-2 perper centcent causedcaused byby water losseslosses will lead toto an impairedimpaired working capacity.capacity. For each per cent dehydration of body weight, body temperaturetemperature will riserise aboutabout 0.2°C0.20 C andand thethe pulsepulse raterate will riserise aboutabout 1010 beats/Min.beatsjrnin. If the body weight decreases by fivefive perper cent there isis a riskrisk of exhaustionexhaustion andand collapse.collapse. preferably,Preferably, the water should be replacedreplaced by drinking smallsmall quantities severalseveral timestimes perper hour.hour. Sometimes 5-6 litres per work shift,shift, oror eveneven more,more, cancan bebe required.required. Sweating also means a lossloss ofof salt,salt, which hashas toto bebe replaced.replaced. Water and salt can be supplemented by drinking 0.10. 1 perper centcent saltedsalted water ifif largerlarger quantities of water have toto bebe replacedreplaced and thethe saltsalt containedcontained inin foodfood isis insufficient.insufficient. It should be observed that the salt should be taken together with liquid.liquid. -

- 53 -

Heat stress disorders

Heat reactionsreactions areare broughtbrought aboutabout byby bothboth internalinternal andand externalexternal factors and willwill not only result in physiological reactions but in psycho-physiological reactionsreactions as well, which may affect the working capacity and increase thethe riskrisk of accidents. The mental performance may decrease and behavioural disturbances inin thethe formform of aggression, hysteria and apathy, or lossloss of normal social inhibitionsinhibitions might occur.

In the following, three major conditions are discussed according to their causes, symptoms and treatment, namely: heat cramps, heat exhaustion and heat stroke.stroke.

Elderly persons, overweight persons, alcoholics, chronic invalidsinvalids and small children are in general more susceptible to heat reactionsreactions thanthan others.

A. Heat cramps

Heat cramps occur when therethere isis aa deficiency of both water andand salt,salt, e.g. if the person has been sweating heavily and drinks large volumes of water but with nono compensationcompensation forfor thethe saltsalt loss.loss. It is characterized by painful spasmsspasms inin thethe skeletalskeletal muscles. The legs and abdomen areare likelylikely toto be affected first.first.

First-aid treatment includes the following:

1. Give the victim sipssips of salt water - one teaspoonfulteaspoonful of saltsalt perper glass - half a glass every 15 minutes, overover a period of aboutabout oneone hour.

2. Exert pressure with your hands on thethe crampedcramped muscles, or gentlygently massage them, to help relieverelieve spasm.spasm.

Heat cramps are often anan early stagestage ofof heatheat exhaustion.exhaustion.

B. Heat exhaustion

Usually heatheat exhaustionexhaustion isis causedcaused byby eithereither waterwater lossloss (pisoS a lacklack ofof salt, or both. The body temperature can be normal or about 38 C.c. The victim is very weak and sufferssuffers fromfrom nausea,nausea, dizziness,dizziness, andand perhapsperhaps headache and cramps.cramps. The body tries toto loselose heat by excessive pooling of blood in the capillaries of thethe skin.skin. This reducesreduces the blood supplysupply toto thethe vital organs, such as brain, heart, andand lungs.lungs.

The skin becomes whitewhi te oror pale,pale, coolcool andand clammy.clammy. The person may faint if standing, but will probably regainregain consciousness if his head isis lowered and the blood supplysupply toto thethe brain isis improved.improved.

First-aid measures includeinclude thethe following:following:

1. Give the victim sips of salt water - one teaspoonfulteaspoonful of saltsalt perper glass - half a glass every 15 minutes, over a period of aboutabout oneone hour. - 5454 -

2. Have thethe victimvictim lielie downdown withwith feetfeet somewhatsomewhat raised.raised.

3. Loosen clothing.clothing.

4. Move the victim toto aa coolercooler environment or intointo thethe shadow and apply a cool, wet clothcloth andand fanfan thethe victim.victim.

5. Afterwards thethe victimvictim shouldshould restrest forfor severalseveral daysdays andand notnot bebe exposedexposed to abnormally highhigh temperatures.temperatures.

Dehydration exhaustion is a form of heat disorder which may occur after several days ofof work inin thethe heat.heat. If water losses are not replacedreplaced daily, progressive dehydrationdehydration cancan severelyseverely reducereduce work capacity.capacity.

c.C. Heat stroke

Heat stroke isis thethe mostmost seriousserious ofof heatheat disordersdisorders andand maymay bebe fatal.fatal. Heat stroke occurs when thethe body'sbody's heat controls fail.fail.

The symptoms areare hot,hot, redred andand drydry skin.skin. The temperature isis about 41°41 0 C and rising. The pulsepulse isis rapidrapid andand strong.strong. There may be signssigns of brain disturbances, suchsuch as mental confusion, delirium, convulsionsconvulsions or unconsciousness. Heat stroke is an immediate medical emergency and the mortality raterate isis high. First-aidFirst-aid treatmenttreatment shouldshould alwaysalways be initiatedinitiated immediately without waiting forfor transporttransport toto aa medicalmedical facility.facility.

First-aid treatmenttreatment includesincludes thethe following:following:

1. Cool the body quickly. H~ver,Horver, preventprevent overchillingoverchilling onceonce thethe bodybody temperature falls belowbelow 3939 C.C.

Whenever a person's bodybody temperaturetemperature reachesreaches 400C,400 C, thethe followingfollowing first-aid measures shouldshould bebe taken:taken:

- Undress and soaksoak thethe victim continuouslycontinuously with coldcold water oror rubrub with alcohol, oror placeplace himhim inin coldcold waterwater untiluntil thethe temperaturetemperature isis lowered.lowered.

- Increase evaporation andand convectionconvection byby fanning.fanning.

- Do not givegive thethe victimvictim stimulants.stimulants.

- Treat for shockshock (according(according toto first-aidfirst-aid andand emergencyemergency treatment).treatment).

Prevention of heat stress disorders

A hot and humid environment, with lowlow airair velocity, resultsresults inin aa limited evaporation ofof sweat.sweat. It is then necessary toto avoid excessiveexcessive heatheat stress by facilitating the performance of heavy jobsjobs as much as possible. The solution is preferably not to decrease the number of working hours per day, but to reduce the physical workload, or increaseincrease periods of rest,rest, or when possible organize forfor workwork inin aa coolercooler placeplace duringduring heatheat peaks.peaks. - 5555 -

Examples ofof howhow toto fitfit thethe jobjob toto thethe workerworker withwith regardregard toto heatheat are:are: scheduling of working hours, provision of shelter, availability of drinking water (and(and salt):salt):

1. Provide shelter whenever possible, e.g.e.g. inin nurseries so as to protect workers againstgiiisE the direct raysrays of thethe sunsun during work, oror makemake useuse of natural shade,shade, e.g. in natural forestforest leave a few wide-crowned trees as sheltershelter forfor loadingloading areasareas andand futurefuture plantingplanting activities.activities.

2. Allow frequentfrequent restrest periodsperiods toto allowallow thethe bodybody temperaturetemperature toto decrease, prefeaBliipreferaoly iinael: linaer shadeshade nearnear thethe worksite.worksite.

3. Make suresure thatthat drinkingdrinking water isis alwaysalways available.available. The workers should bebe encoUia-ijeaencouragea to-drinkIo-dY-iiik small small quantities quantities frequentlyfrequently..

4. Organize thethe work patternpattern soso thatthat thethe heaviestheaviest work cancan bebe carriedcarried out inin thethe eaT1-1-7early mornIng TmoTnin-§ while while the the air air is is cooler, cooler, and and changechange toto lighter work inin thethe heatheat ofof thethe day.day. In extreme conditions changechange toto one single session with work only in the early morning or split session with work in the morning and later afternoon.

To some extent it is also possible to improve the worker's fitness for work in a hot climate throughthrough proper clothing,clothing, acclimatization and physical fitness.fitness.

- Clothing

Clothes will have another functionfunction andand designdesign inin a dry climateclimate with or withoutwithout considerable radiantradiant heat, thanthan inin a hot and humid climate, e.g.e . g. inin thethe rainforest.rainforest.

First, clothes shouldshould protect against thethe solarsolar radiantradiant heat butbut should not reduce evaporation and convection by isolation.isolation. Loose-fitting clothes, in bright colours, are usually recommended.recommended . The material should be lightweight. When carrying out heavy work itit may, however, be better to wear thinthin andand close-fittingclose-fitting clothes,clothes, whichwhich willwill bebe quicklyquickly soakedsoaked withwith sweat, and thereby increase the cooling by evaporation.

If the radiant heat load is lowlow thethe principle isis toto wear as littlelittle clothing as possibe.possibe. When working inin thethe forestforest or handling chemicals inin the nursery, etcetc.,. , clothes are, however, necessary for protection. Particularlyparticularly inin a hot and humid climateclimate thisthis maymay reducereduce thethe working capacity considerably and increaseincrease thethe riskrisk ofof heatheat stress.stress.

By making suitablesuitable clothesclothes available,available, thethe employeremployer cancan helphelp thethe worker toto adaptadapt himself,himself, asas farfar asas possible,possible, toto weatherweather conditions.conditions.

- Acclimatization

Through physiological processes a person will also adapt toto work under heatheat stress.stress. These processess areare calledcalled acclimatization.acclimatization.

The most importantimportant way forfor thethe bodybody toto givegive offoff excessexcess heatheat isis byby sweating. During the first weeks and especially thethe firstfirst twotwo toto fourfour days of work inin a hothot climateclimate thisthis abilityability willwill increase.increase. The degree ofof acclimatization willwill thusthus bebe inin relationrelation toto howhow muchmuch thethe personperson sweats.sweats. - 5656 -

The increased raterate of sweating seems to occur whenwhen the sweat glands have got "trained""trained" toto startstart sweating.sweating. The sweat will also have aa lowerlower salt concentration when acclimatized.acclimatized. Acclimatization isis also accompanied by decreased pulse raterate and body temperature at a given work load inin a hot climate.

After a break inin thethe work of about twotwo weeks the acclimatization will already bebe lost.lost. This should be considered whenwhen e.g. a workerworker starts workwork again after a period of vacation or sick leave, and thus full production cannot be expected duringduring thethe firstfirst week.week.

- Physical fitness

A physicallyphysically fitfit personperson hashas aa well-developedwell-developed circulationcirculation capacity,capacity, asas well as anan increasedincreased bloodblood volumevolume andand startsstarts toto sweatsweat atat lowerlower bodybody temperature, which areare essentialessential factorsfactors inin regulatingregulating bodybody temperature.temperature. The process of acclimatization isis also faster for the fit person than for the unfit.

Health problems inin thethe cardiovascularcardiovascular systemsystem or kidneys are supposedsupposed to decrease tolerancetolerance toto heat.heat. Overweight persons seem also to be more frequent victims of heatheat stressstress disorders,disorders, suchsuch asas heatheat stroke.stroke.

Cold climate and snow

The other extreme which generally causes inconvenienceinconvenience toto thethe forestforest worker isis a cold climateclimate particularlyparticularly inin combinationcombination with snow.snow. Chainsaw operators, inin particular, suffersuffer fromfrom thethe cold,cold, which provokesprovokes thethe symptomssymptoms of vibration-induced white fingersfingers (see(see SectionSection 3.2.33.2.3 'Vibration")."Vibration").

AsA$ alreadgalreadl mentioned,mentioned, thethe optimaloptimal airair temperaturetemperature forfor aa nakednaked humanhuman being isis ca.ca. 2828 C.C. When thethe airair temperaturetemperature isis lowerlower thethe bodybody willwill loselose heat by convection and radiationradiation toto thethe environment.environment. To decrease thisthis transfer of heat thethe peripheral bloodblood vessels, particularlyparticularly inin thethe fingersfingers and toes, contract soso asas toto reducereduce thethe blood flow.flow. In this way the isolating effect of thethe skinskin cancan increaseincrease upup toto sixsix times.times. Another effecteffect is an increased metabolism caused by an automatic shivering of the skeletal muscles. As the mechanical efficiency will be zero percent, heat production isis high.high. The metabolism may in this way increase threethree toto four times compared toto thethe basalbasal metabolism.metabolism.

The usual way to protect oneself against the cold when working isis to wear proper clothing.clothing. The work shouldshould alsoalso bebe organizedorganized soso asas toto avoidavoid allall unnecessary w8rk~rk inin open areasareas when therethere isis wind. The 800linggooling effecteffect isis the same at 0 C and an air velocity of 55 m/sec,mVsec. as atat -8 CC andand nono wind atat all. Neither very lightlight nornor veryvery heavyheavy physicalphysical workwork shouldshould bebe carriedcarried outout in very cold weather,weather, but an optimal physical activity should be maintained. Work inin deepdeep snowsnow shouldshould bebe avoided.avoided.

Clothing

Air isis a poor conductorconductor ofof heatheat andand thereforetherefore anan excellentexcellent isolator.isolator. Most of the efficient isolatorsisolators consistconsist of material which enclosesencloses airair inin small chambers.chambers. This isis alsoalso thethe principleprinciple forfor clothes.clothes. The isolating - 57 - capacity of a cloth depends on its thickness, whichwhich normally meansmeans the thickness of the layerlayer ofof air.air. Between different layers of clothcloth therethere isis also enclosed air.air. More layers will therefore increase the resistance to thermal transfer fromfrom thethe body.body .

3.1.3.1.2 2 Topography

This section will deal with thethe particular problems relatedrelated to work at high altitudes, on steepsteep slopes and in remote work places where timber has toto be transportedtransported longlong distancesdistances toto reachreach roads,roads, waterways or railways,railways, and also to work atat aa longlong distancedistance fromfrom dwellingsdwellings andand socialsocial services.services.

High altitude

Aerobic powerpower isis diminisheddiminished atat aa highhigh altitudealtitude duedue toto reducedreduced oxygenoxygen pressure inin thethe inhaledinhaled air.air. Reduced aerobic power means a decreased physical working capacity.capacity.

When aa person livingliving atat seasea levellevel moves toto aa higherhigher altitudealtitude his maximal intake of oxygenoxygen will decrease by about 5%5% or more atat about 2,000 metres above seasea level.level. At 3,000-3,5003,000-3,500 m.m. itit willwill bebe reducedreduced byby 10-15%.10-15%. At 4,0004,000 m.,m. , thethe aerobicaerobic capacitycapacity isis reportedreported byby bebe reducedreduced byby aboutabout 30%.30% . Individual variation is,is, however,however, considerable.considerable. Gradually one will acclimatize and thethe reductionreduction will be only about half. The problem willwill remain for forestry workers who occasionally have to work at high altitudes, whilst stillstill livingliving at lowlow altitudes.altitudes. ForestForest work which isis already very heavy under normal conditions will be extremely heavy forfor these workers, who are not adapted toto thethe higher altitude.altitude.

Another problemproblem maymay occuroccur whenwhen thethe workwork isis carriedcarried outout inin aa hothot climate and at aa lowlow airair pressure.pressure. Up toto about 3,0003,000 m,m. aboveabove seasea levellevel the air pressure should not have any major influence on heat stress,stress, but the competition between the demands for oxygen and heat transportationtransportation will be bigger when the oxygen concentration decreases (Axelson,(Axelson, 1979).

Steep slopesslopeS and difficult terrain

Workingworking onon steepsteep slopesslopes andand inin difficultdifficult terrainterrain willwill veryvery oftenoften increase energy consumption considerably, particularly ifif one has to carry heavy loads suchsuch as heavyheavy tools,tools, oror pullpull winch cables.cables.

Special tools and equipment may be needed, suchsuch as:as:

- Planting hoes with a shorter handle when planting on steepsteep slopes.

- Seedlings should preferably be carried inin a back pack insteadinstead of in baskets carriedcarried byby hand.hand.

- Footwear with a good grip~rip should be used when working on steepsteep slopes or ifif thethe soilsoil isis slippery.slippery.

There are many additionaladditional risksrisks when working onon steepsteep slopesslopes with animals such as horses, donkeys, mules and oxen forfor carryingcarrying oror skiddingskidding timber or loads.loads. When used forfor dangerous work inin suchsuch terrainterrain thethe animalsanimals must be well-trained andand good-temperedgood-tempered andand onlyonly ledled byby experiencedexperienced men.men. A safe distance from animal-hauled loads shouldshould be maintained. - 58 -

When working with tractorstractQrs onon steepsteep oror roughrough terrain, therethere isis a riskrisk of overturning backwards oror sideways.sideways. Often this kind of accidentaccident isis fatalfatal and shouldshould bebe preventedprevented byby allall possiblepossible means.means. Only experienced tractortractor drivers with technicaltechnical knowledgeknowledge and skill shouldshould be employed on dangerous work, such as driving on steepsteep slopes,slopes, particularly when the ground surface is slippery or loose andand when drivingdriving withwith heavyheavy loads.loads.

If the tractor has a cab or frame strong enough to resist destruction when overturning, thethe driver's chanceschances of survival will increase considerably. Many accidents could also be avoided by daily checks and regular maintenance of brakes.

Other particularly riskyrisky jobsjobs onon steepsteep slopesslopes or roughrough terrainterrain when special attention to safety matters isis called for are: felling timber downhill, the use of winches, installationsinstallations for hoisting and haulage, and timber chutes.chutes. Only experienced supervisorssupervisors andand workersworkers shouldshould havehave thethe responsibility of carrying out the mostmost dangerous activities; good-quality material andand equipmentequipment shouldshould bebe used;used; safetysafety checkschecks and maintenance shouldshould be regular and frequent; winches and cables must be clearly marked for maximum loads,loads, andand safetysafety regulationsregulations atat thethe workplace shouldshould bebe strictlystrictly followed.

The operations must be soso planned thatthat nobody is working inin dangerous zones, e.g. no worker should work downhill from other workers when there is the risk of material rollingrolling oror slidingsliding down.down.

Many operations requirerequire communicationcommunication between the workers, but due to long distance or poorpoor visibility thethe communicationcommunication maymay bebe obstructed.obstructed. Where thisthis problem isis not solvedsolved byby radioradio communication,communication, signalssignals byby motion of arms and hands and soundsound signalssignals byby whistle oror horn are common.common. Many fatal misunderstandings can be avoided if a clear, simple signalling system known by all workers isis employed.employed. No workers should be engaged inin such operations before theythey are familiarfamiliar with thethe practicalpractical use ofof thethe system.system.

There are many additional difficulties and risksrisks to foreseeforesee and prevent when working onon steepsteep andand roughrough terrain.terrain. But it isis beyondbeyond thethe scope of this publication toto gogo intointo furtherfurther details.details.

Workwork in remoteremote areas

Many forestryforestry operationsoperations involveinvolve transporttransport overover longlong distances.distances. workersWorkers have toto move toto remoteremote logginglogging oror plantingplanting areas daily, weekly or for longer periods. When workers livelive closeclose toto thethe worksite itit isis commoncommon for them to useuse a considerable part of their working day for walking between their dwellings and places ofof work. This is not only time-consuming but also requiresrequires aa lotlot ofof energy.energy. It is common, asas well,well, to travel on timber lorrieslorries not equippedequipped oror adaptedadapted forfor passengerpassenger transport. Many serious accidents occur during suchsuch transport.transport. In Section 6.1 "Working"Working and LivingLiving ConditionsConditions ofof ForestryForestry Workers inin General" problems relatedrelated to stayingstaying inin remoteremote areasareas andand inin campscamps will bebe dealt with in more detail.

Heavy timbertimber fromfrom remoteremote logginglogging areasareas hashas toto bebe hauledhauled inin roughrough terrain to main roads,roads, waterways oror railways.railways. The riskrisk of accidents isis high when setting heavy loads suchsuch as logslogs inin motion under conditionsconditions which - 59 - are difficult to control.control. Plenty of strenuous manual work isis required,required, sometimes with thethe helphelp ofof animals.animals. The particular problems connected withwith transport and loading will be further discussed in Section 6.5 "Transport and Loading".Loading".

Also seedlingsseedlings mustmust bebe transportedtransported toto remoteremote plantingplanting areas. More about plantation work cancan bebe foundfound inin Section 6.3 "Planting"Planting ActiActivities".vi ties" .

3.1.3 Harmful plants,plants, wood,wood, animals,animals, snakes,snakes, insects,insects, infections, etc.etc.

Anybody spendingspending much timetime working inin thethe forestforest will probablyprobably encounter some problems inin termsterms ofof injuries,injuries, infections or allergic reactions due to contact with plants withwith thorns and splinters, poisonous plants, insectsinsects andand sometimessometimes eveneven animals.animals. The type of problem will vary greatly with the climate, vegetation, conditions of livingliving and standard of hygiene.

Because thethe conditionsconditions vary soso much between different regionsregions only the very general or very severesevere problems will be discussed inin thethe following.

In general, workers living in the same area as they are working are familiar with the local conditions and know how to discriminatediscri~nate between harmful and harmless plants, animals, etc. and how toto behave inin case of insury. workersWorkers fromfrom other regionsregions oror with an urban backgroundbackground havehave toto learn this and adaptadapt toto thethe locallocal conditions.conditions.

A. Harmful plants and wood

Not much has been written about thethe effects on forestryforestry workers of harmful plants, eithereither inin termsterms ofof injuriesinjuries fromfrom splinters,splinters, sharpsharp edgesedges andand thorns or allergic reactionsreactions fromfrom contactcontact withwith harmfulharmful plants.plants.

Problems may arise when workers with no ruralrural background, or fromfrom other regions,reg10ns, are recruited.recruited. Special attention should then be given to these workers so that they become aware of the risksrisks and are able to recognize the plants, the symptoms of illness and learn about simple treatment. The supervisor may keep specimens and drawings accessible for the workers.

The most efficient way toto learnlearn toto recognizerecognize aa plant isis toto seesee itit inin its natural environment.environment. Drawings oro~ photographs, although they are poor substitutes, are widely used.used. The drawingsdrawings should not only show the morphology and colours ofof thethe plant,plant, butbut alsoalso itsits naturalnatural surroundings.surroundings. Important seasonal changeschanges shouldshould alsoalso bebe illustrated.illustrated.

In addition,addition, there should be a list of all the harmful plants, fruits and berries inin thethe area.area. Poisonous mushrooms, berries and fruits are easily mistaken forfor edibleedible ones.ones.

Around forestforest villagesvillages andand campscamps oror otherother areasareas wherewhere workersworkers (and(and their families) congregate, poisonous plants should, ifif possible, be destroyed. If they are burned, this should be done in an isolated place and contact with thethe smokesmoke shouldshould bebe avoided,avoided, asas toxictoxic fumesfumes maymay develop.develop. - 60 -

Most reactionsreactions fromfrom contactcontact withwith poisonouspoisonous plantsplants areare allergic.allergic. The reactions are characterized by itching,itching, redness,redness, rash,rash, headachesheadaches andand fever.fever. Sometimes blisters andand swellingswelling willwill occur.occur. The victim may bebe illill forfor several days, oror eveneven longer.longer. The symptoms normally appear within aa fewfew hours, but may be delayed upup toto 24-4824-48 hours.hours. Exposed skin should be carefully washed with plentyplenty ofof coldcold water.water. Clothing and toolstools which have been in contact with the poisonous plants should be washedwashed withwith soap andand water.

Very commoncommon typestypes ofof injuriesinjuries amongamong forestryforestry workersworkers areare cuts,cuts, puncture wounds, scratches or abrasions, due toto touching or handling stingingstinging plants,plants, or plants whichwhich break into sharp splinters and edges oror have thorns.thorns.

well-fittingWell-fitting clothing of stoutstout material with ends of trousers and shirtsleeves tied over shoes and gloves, or long gloves or leggings will protect the worker fromfrom accidentalaccidental contactcontact inin areasareas withwith harmfulharmful plants.plants. The first-aid kit should have forceps forfor the removalremoval of splinters and thorns. When pruning and cuttingcutting thornythorny trees,trees, suitablesuitable toolstools are also essential in order toto avoidavoid injuries.injuries.

In sawmills, veneeveneerr industries, , etc., residue of resin sap and other constituents of wood can cause allergic reactions after touching or breathing. Susceptible workersworkers should be transferred to jobs withwith asas little contact with thethe wood asas possible.possible. Workplaces shouldshould bebe wellwell ventilated.

Exposure to toxic wood and wood dust isis further discussed in Section 6.7 "Wood"Wood Processing".processing".

B. Animals

Domestic animals A number ofof animalsanimals areare used inin forestryforestry forfor dragging andand carryingcarrying loads, e.g. horses,horses, mules,mules, donkeys,donkeys, camels,camels, oxen,oxen, buffaloesbuffaloes andand elephants.elephants. There is a great riskrisk of accidents occurring ifif thethe animals areare notnot treatedtreated with care.care. Only patient and calm persons with experience should be employed toto taketake carecare ofof andand workwork withwith thethe animals.animals. Even well-trained and good-tempered animals can be spoiled inin aa shortshort timetime ifif treatedtreated badlybadly by a nervous and unbalanced person, and may thusthus createcreate dangerous situations.situations.

It should always be kept in mind to stay in a safe position and keep a line of retreatretreat when near animals soso as toto avoid being pushed against a wall, or toto bebe inin thethe way ofof suddensudden movementsmovements ofof thethe feetfeet oror headhead ofof thethe animal. Particularly when the animal isis annoyed by insects and heat, its movements will bebe unpredictable.unpredictable.

It takes considerable time, effort and experience to train animals for the difficult andand hazardoushazardous taskstasks whichwhich areare commoncommon inin forestforest work.work. After lay-offs thethe animalsanimals shouldshould bebe approachedapproached withwith muchmuch carecare andand patiencepatience when used inin workwork again.again. Harnesses, saddles,saddles, bridlesbridles andand otherother aidsaids shouldshould be adjusted forfor both thethe worker andand thethe animal,animal, andand thesethese aidsaids shouldshould bebe kept inin goodgood condition.condition. Reins must never be wrapped around the wrist or body but held firmlyfirmly inin thethe hands.hands. - 61 -

When the animals are tethered,tethered, too much slack shouldshould be avoided as the animal might otherwise get entangled or come into contact with hazardous objects suchsuch asas barbedbarbed oror looseloose wires.wires. As far as possible, the animals should be protected fromfrom insects.insects.

Many domestic and wild animals spread diseases to men, such as brucellosis, tularaemia,tularaemia, spottedspotted fever,fever, malaria and rabies.rabies. The means of transmitting infection varies for the different diseases and could, for example, be through direct contact,contact, bites fromfrom insectsinsects or fromfrom thethe animal itself, or consumption ofof infectedinfected food.food. Cleanliness isis alwaysalways oneone important preventive measure. Wildwild animals

Large wild animals in the forest are generally rare and seldom create problems forfor forestforest workers.workers.

Monkeys and apes cancan sometimessometimes be dangerous, and theirtheir behaviour isis often unpredictable. They can give nasty bitesbites ifif irritated.irritated. There isis a risk ofof infection in all animal bites,bites, andand therethere isis alsoalso aa riskrisk ofof tetanus.tetanus. Most monkeys andand apes cancan bebe rabidrabid andand soso itit isis unwiseunwise toto enticeentice themthem toto visit campsitescampsites byby feedingfeeding them.them.

Rabies

Rabies is an infectious disease caused by a number of animals inin most parts of the world. Primarilyprimarily itit isis transmittedtransmitted byby dogs, butbut severalseveral otherother animals can be affected andand spreadspread it,it, forfor exampleexample cats,cats, cattle,cattle, rats,rats, bats, mice, martens, foxes,foxes, wolves, skunkskunk andand deer. Rabies is caused by a virus inin thethe salivasaliva ofof thethe diseaseddiseased animal.animal. The virus can only enterenter thethe human body throughthrough the brokenbroken skin,skin, lipslips and conjunctivae.conjunctivae. The virus can be present in a dog's salivasaliva twotwo daysdays before thethe dogdog showsshows anyany symptomssymptoms ofof rabies.

The virus will easily bebe destroyeddestroyed byby light,light, heatheat andand disinfectantsdisinfectants when outside thethe rabidrabid animalanimal oror onon inanimateinanimate objects.objects. It is therefore notnot necessary toto destroy clothing,clothing, etc.etc.

The firstfirst symptomssymptoms appearappear twotwo toto fivefive weeks afterafter infection.infection. The animal may change its behaviour entirelyentirely and may display unprovoked aggression. Later it will develop partialpartial paralysis, havehave difficulties inin drinking andand will staggerstagger about.about. CompleteComplete paralysis,paralysis, convulsionsconvulsions andand deathdeath will followfollow within aa fewfew days.days.

If bitten by an animal suspected of being rabid,rabid, the victim shouldshould wash thethe wounds immediately,immediately, withwith copiouscopious amountsamounts ofof soapysoapy waterwater oror detergent, soso asas toto removeremove asas muchmuch asas possiblepossible ofof thethe rabiesrabies virus.virus. Movements shouldshould bebe avoidedavoided untiluntil afterafter medicalmedical carecare hashas beenbeen obtained.obtained. Medical advice shouldshould alwaysalways bebe soughtsought asas soonsoon asas possible,possible, asas therethere isis nono cure once thethe finalfinal symptomssymptoms appear.appear.

-Snakes - - Most people have a fearfear of snakes, but on the wholewhole they cause few problems toto forestforest workers.workers. Mostly, snakessnakes seekseek covercover whenwhen disturbed.disturbed. They usually onlyonly attack when touched,touched, troddentrodden on,on, oror whenwhen theythey cannotcannot escape. - 62 -

Bites fromfrom even thethe most venomous snakes do not usually resultresult in deathdeath.. The mortality has been estimated at less than 10%, mainly because the snake is very seldom able to inject the full dose of venom. Venoms from different snakessnakes affectaffect thethe victim inin differentdifferent ways, suchsuch as effects on the nervous system, on the circulatory system, destruction of red blood cells and disturbance ofof thethe bloodblood clotting.clotting. Snake bites normally occur on the limbs, especially onon thethe feetfeet andand legs.legs.

In areas with poisonous snakes the workers should wearwear high boots oror leggings and thethe workingworking groupgroup shouldshould bebe equippedequipped withwith aa snakesnake bitebite kit.kit. The employer shouldshould havehave anti-snake bitebite serumserum available.

When working inin thethe forestforest oneone hashas toto watch where toto tread,tread, especially inin placesplaces where snakessnakes couldcould bebe resting,resting, forfor exampleexample among rocksrocks and logs,logs, underunder timbertimber stacks,stacks, oror hiddenhidden byby foliage.foliage. Stacked material such as shouldshould onlyonly be moved with an appliance,appliance, e.g.e.g. aa bar, and never with bare hands.hands.

Some poisonous snakessnakes livelive inin treestrees and may attack men passing underneath, which isis anotheranother reasonreason alwaysalways toto wear aa safetysafety helmet inin thethe forest. Some knowledge of first-aid treatmenttreatment isis an advantage when someone is bitten by aa snake.snake. If possiblepossible,, the snake shouldshould bebe killedkilled andand identifiedidentified as poisonous oror harmless.harmless. A careful examination of the bite may also answer that question: marks of twotwo rowsrows ofof contiguouscontiguous teethteeth indicateindicate thatthat it waswas a harmless snake; two fang marks may indicate that the snake was poisonous. Sometimes there is only one fang mark, and sometimes three to four, depending onon howhow manymany ofof thethe fangsfangs havehave penetratedpenetrated thethe skin.skin.

If bitten by a poisonous snake, treatment isis urgent and first aid should be given.given. The first-aidfirst-aid treatmenttreatment aimsaims atat reducingreducing thethe blood circulation throughthrough thethe bite, soso asas toto slowslow downdown thethe absorption ofof venom.venom. The victim shouldshould restrest and not move thethe involvedinvolved bodybody part.part. The involvedinvolved part should be inin a loweredlowered position, ifif possiblepossible belowbelow thethe levellevel of thethe heart. The bite shouldshould be washed thoroughlythoroughly with soapsoap and water, or whatever liquid isis available. DoDo notnot rub.rub. Apply a slightlyslightly constricting bandage about 5-105-10 cmem above thethe bite,bite, betweenbetween thethe bitebite andand thethe victim's heart. The bandage should be snug but not tootoo tight.tight. Do not give the victim alcohol oror morphine.morphine.

In general, it is not recommendedrecommended to make incisionsincisions followed by suction.suction. Often the incisionsincisions will be a bigger problem forfor the victim than the bite itself.itself. It is betterbetter to take the victim to a hospital as soon as possible for an anti-venom injection.injection.

§c~r£i~n~,_s£i~e!s_~d_l~e£h~sScorpions, spiders and leeches There are different speciesspecies ofof scorpions.scorpions. SomeSome cancan bebe dangerous.dangerous. Their sting, by thethe tail,tail, rarelyrarely causescauses death, butbut most oftenoften nausea,nausea, vomiting, abdominal pain, shock,shock, convulsionsconvulsions andand sometimessometimes coma.coma. In a scorpion area itit isis good habit toto "knock-out""knock-out" thethe shoesshoes beforebefore wearing them. The scorpions are usually concealed under stonesstones and fallenfallen branches etc. during thethe day.day. - 63 -

Most spiders have poison glands, but very few are dangerous. The spider-like tarantulas give bites which are not poisonous, but result in severe wounds.

Leeches areare oftenoften aa problemproblem forfor forestforest workers,workers, especiallyespecially inin dampdamp forests,forests, near streams, or inin marshy areas.areas. Even when workers wear trousers, puttees and laced high boots, thethe smallsmall landland leechesleeches may findfind their way to thethe skin. The bites do not give a sensationsensation of pain but will often bleed for some time.time. Because the bites may cause sepsis they should be treated with care.

If the leech is dragged or pulled from the skin its suction apparatus may bebe leftleft andand causecause inflammationinflammation andand suppuration.suppuration. To get thethe leechleech off,off, salt or vinegar cancan bebe applied.applied. A hot needle or lighted cigarette may also help.

Rubbing an insectinsect repellentrepellent on thethe legslegs and clothes will prevent thethe leeches fromfrom biting.biting.

Insects

Several diseases, particularly inin warmwarm climates,climates, are spread by different insects.insects. The insectinsect can either play thet he rolerole of a direct carriercarrier of thethe disease: fromfrom man toto man,man, oror fromfrom animalanimal toto man;man ; oror itit cancan bebe thethe host inin which thethe causalcausal organismorganism multipliesmultipli es oror undergoesundergoes certaincertain developments.

The direct transfer can be mechanical, e.g.e .g. the causal organism can adhere toto thethe insect'sinsect's legslegs oror otherother partsparts ofof thethe body.body. The insectinsect cancan then infect,infect, e.g.e .g . thethe food.food. In the following table some importanti mportant andand common diseases and thethe insectsinsects spreadingspreading themthem areare listed.listed.

Table 4.4. Some examples of insectsinsects andand thethe diseases theythey may spread.spread.

Insects Diseases Mosquitoes: Anopheles Malaria,malaria, Tularemi Culex Filariasis Aedes Yellow fever, Dengue fever

Flies Loa-Loa African sleepingsleeping sicknesssickness (trypanosomiasis) by tse-tse flies Sandfly fever, Dysentery

Ticks Relapsing fever,fever, Tick typhustyphus

Fleas Plague (from(from ratrat toto man)man)

Mites Scabies, itch, scrub typhus fever

Lice Epidemic typhustyphus fever,fever, Relapsing feverfever - 64 -

One of the most important diseases among forest workers in many developing countries,countries, particularlyparticularly inin thethe tropics,tropics, isis malaria.malaria. Malaria isis caused by certain mosquito species belonging to the tribe of the night-flying Anopheles.Anopheles. Since the late seventies the incidence ofof malariamalaria has increased dramatically due toto thethe parasite becoming resistantresistant to many preventive medicines.medicines.

The malaria parasite The parasite is transferred

is transferred~ransferred byby ~oto the~he next person to~o the mosquito stingsting repeat the cycle

6

The parasite penetrates into the liverliver

\

The parasite penetrates intointo thethe redred blood corpuscles wherewhere itit multiplies toto such an extentex~en~ that~ha~ the~he blood corpuscles burst, releasing poison intointo thethe bloodstream and causing feverfever andand shiveringshivering fitsfits

Figure 21.21 . The three phases of the life cyclecycle of thethe malaria mosquito. - 65 -

The victim will havehave feVerfever forfor somesome days, which occurs when thethe redred cells burst and releaserelease theirtheir parasites (see(see the life cycle of the malaria parasite inin FigureFii*re 21).21). Anaemia will followfollow thethe repeatedrepeated lossloss of haemoglobin. frethe spleen will enlarge when taking care of the rupturedruptured red cells. The victim may recover, die or survive but withwith a number of parasites leftleft inin thethe bodybody causingcausing illill health.health.

The symptoms of malaria are more or lessless thethe same as for many other fevers inin thethe tropics.tropics. It is, however,however, easy to identify the malaria parasite byby microscopicmicroscopic bloodblood tests.tests. The parasite can then be killed in the blood by anti-malarial drugs.drugs. The anti-malarial drugs can also be used as prophylaxis. Other preventive measures are: to use protective clothing between dusk and dawn, which isis thethe timetime when thethe anophelineanopheline mosquitoes usually bite.bite. The use of insect repellents and a mosquito net over the bed when sleepingsleeping areare otherother measuresmeasures whichwhich maymay bebe taken.taken.

Of allall thethe diseasesdiseases spreadspread byby insectsinsects whichwhich troubletrouble many forestforest workers, onlyonly malariamalaria hashas beenbeen brieflybriefly discusseddiscussed here.here. There are many other diseases spreadspread by insects,insects, not soso widespread or commoncommon asas malaria, but which are nevertheless aa seriousserious problem,problem, locallylocally or regionally.regionally. Forest workers, and otherother staff,staff, shouldshould thereforetherefore be aware ofof andand havehave knowledge about preventive measures and simplesimple treatment.treatment.

Infections

Infections and poor health are common among forest workers in many developing countries, and thethe reasonsreasons areare several.several. Living conditions areare usually poor with insufficientinsufficient sanitary andand hygienehygiene facilities,facilities, thethe dietdiet often lacks proteins andand vitamins, and thethe calorificcalorific contentcontent isis generallygenerally low, the drinking water may be contaminated,contaminated, medical servicesservices areare veryvery often poor, if any, and clothing inappropriate.inappropriate. Many diseases areare endemicendemic to the tropics.tropics. Forest workers may continously be suffering from poor health, which certainly will affect theirtheir efficiencyefficiency and work output,output, andand cause frequent absenteeism.absenteeism.

Common infectionsinfections among forestforest workers are:are: fevers,fevers, e.g.e.g. malaria;malaria; respiratory tract infections, e.g. coughs, colds,colds, tuberculosistuberculosis andand throatthroat infections; intestinal infections and skinskin infections,infections, e.g. boilsboils andand stingsting worm; and otherother diseases,diseases, e.g.e.g. tetanustetanus andand tropicaltropical ulcers,ulcers, resultingresulting fromfrom sometimes trivial injuries, suchsuch as abrasions andand cuts.cuts.

Reservoirs, sources and ways of transmission of infections

Infection . !e~eEV~irs,reservoirs, see Figure 22, are man, animals or soil.soil. The reservoirs willwill aboveabove 5.1-1all serve serve asas aa guaranteeguarantee forfor survivalsurvival and multiplication inin suchsuch aa wayway thatthat thethe causalcausal organismorganism cancan bebe transmittedtransmitted toto an appropriate host.host.

Sources of infections are man and animalsanimals which will excreteexcrete thethe causalcausal-oi.g5nism,- organIsm, andand contaminatedcontaminated objects,objects, food, water, air,air, etc.etc.

Waysways ofof transmissiontransmission areare forfor exampleexample directdirect physicalphysical contactcontact betweenbetween the infected person (or(or animal) and thethe nonIiTafcTa;-117.1dircInon=infectea;-indIrect contactCoaact when the causal organism is spread via contaminated objects-oTobjects-or a lhIrahira Person. - 66 -

The length of time thethe different causal organisms can survive outside the host vary considerablyconsiderably -- from,from, forfor example,example, aa fewfew hourshours toto somesome months.months. Good hygiene, particularly hand-hygiene, is an essential preventive measure. Other means of transmissiontransmission areare via~i~ water,~a!eE,_f~09 food or~r_b1o~. blood.

Examples ofof diseasesdiseases spreadspread byby drinkingdrinking waterwater andand foodfood areare typhus,typhus, paratyphus and amoebicamoebic dysentery.dysentery. A disease,disease, suchsuch asas schistosomiasisschistosomiasis (or(or bilharzia) is spread by worms in the water when bathing, or walking on wet grass. It may cause skin, liverliver oror kidneykidney problems.problems.

The causal organism cancan also be carried by a vector, such as ~~~i!o~sLmosquitoes, !l~e~flies and~n3 ticks.!i~k~. For certaincertain diseases diseases Ih-6 the-1,7e-c-t-45r-ais-o- vector-also servesserves as the reservoirreservOIr andand notnot onlyonly asas aa carrier.carrier.

Finally, air isis also a transmitter of infections, and then the infection isis spreadsped either either by by dustdust oror aerosol.aerosol. Preventive measures would be toto keepkeep aa sufficientsufficient distanCe-ol. distance-or -fhiciligh througn Isolating Isolating thethe sourcesource of infection fromfrom susceptiblesusceptible persons.persons.

, , Reservoir Sources of Ways ofof transmissiontransmission infection a) man 1. Contact b) animals Blood && excretions a) direct c) soil from the reservoirsreservoirs b) indirect

2. Vehicle a) water (or(or soil)soil) b) food c) blood and blood products

3. vectorVector (insects such as mosquitoes, flies,flies, ticks)

4. Air a) aerosol b) dust

Figure 22.22. Reservoirs, sources of infection and different ways of transmission ofof infections.infections. Below is a listlist of thet he commoner diseases,diseases, with theirtheir causescauses andand commentscomments onon prevention,prevention, etc.etc. An estimate of theirtheir frequencyfrequency isis alsoa lso included.included.

DiDiseasesease FrFrequencye quency Cause Comments

AnaeAnaemiamia ComCommonmon Poor nutrition. Folic acidac id destroyed byby prolongedprolonged Education in nutritionnutrition coocooking.king . Lack of protein. Malaria: Destroys folicfolic acid reserves.reserves. Eradication of malariama l aria Blood loss:l oss: HookwormHookworm andand otherother parasites.parasites . Proper didisposals posal of faeces - hookwormhookworm droppeddropped inin faeces eentersnters through thet he feetfeet of passers-bypassers- by

DiaDiarrhoear rhoea Very commoncommon BacillBacillarya ry dysentery:dysentery : ContaminatedCo ntam ina ted water andand Proper latrines,latrines, washingwa s hing handshands iindeednd eed Amoebic dysentery:dysentery: food, flies.f lies . BoilingBoi ling drinking waterwate r FoodFood poisoning: poisoning : Keeping cooked foods,foods, Education inin care ofof andand cookingcooking foodfood reheating. TypTyphoid:hoid: Infected water supplies, direct Proper latrines,latrines, washing handshands contamination of foodfood byby hands.hands. Boiling drinking waterwater For all:a ll : Washing uncooked fruitfruit and vegetablesvegetables in cocontaminatedntaminated water.

Guinea CornCommonman IngIngestionestion ofof infectedinfected cyclopscyc l ops (water(water flea).flea). If worm dies or isi s brokenbroken duringduring extraction,extraction, worm Rupture of skins kin and emergenceemergence ofof adult worm severe inflamation of thet he tissuestissues (cellulitis),(cellulitis), '".... 12-18 mmonthsonths aftera fter infection.infection. Worker septicaemiasept i caemia or infectiveinfective arthritis cancan result.result. incapacitatedincapacitated when wormworm becomesbecomes adult.adu l t. Tetanus isis aa well-known complicationc omplica tion ofo f guineAguine,a worm

Hypertension Very commoncommo n Two types - the usualus ual type is benign; causecause Never exceed thethe legall ega l limitlimit forfor headhead loads,loads, in.women,in 'women, unknunknownow n butbu t it is thoughtthought that thethe carryingca rrying particularlypa rtic ularly forfor youngyoung peoplepeople fairly of head loadsl oads isis aa causativecausative factor.factor. (V(Verye r y common inin seseriousrious in young men in latel ate teens or early 20's)20's) men

MaMalarial aria Endemic - AnophelesAnopheles mosquito bitesbites infectedinfected humanhuman andand Spraying ofof workers' houses,houses , drainingdraining ofof aallll workers carries thet he diseasedisease on.on . stagnantstagnant water.water. Regular useuse ofof quininequinine drugs.drugs. affected

Muscular Fairly ClimateClimate isis anan importantimp or tant factor.factor. Lumbago andand Damp clothesc lothes shouldshould notnot bebe worn;worn; whenwhen home,home, diseases commoncommon general backache causedcaused byby climatec limate andand lifting.l ifting. changechange toto drydry clothes.clothes. Emphasis on correctcorrect methods ofof lifting.lifting.

. .. / ... Disease Frequency Cause Comments o Ochnocerciasis Fairly commoncommon inin A chronic non-fatal disease caused byby aa Occurs mainly fromfrom 10°-20°NlOo_20 N inin West Africa,Africa, tropical Africa nematode carried byby thethe simuliumsimulium fly.fly. in the savanna areas & Central and Fibrous nodules appearappear onon thethe skin.skin. Also Avoid bites and control thethe vectorvector South America causes blindness.blindness.

Respiratory Very common CClimatelimate encourages these diseases andand tract indeed, esp.esp. ttropicalr opical rain forest isis ideal.ideal. infection sinusitis and bronchitis

ScSchistomoniasishistomoniasis Common A blood fluke which enters throughthrough thethe skinskin Also aa cause ofof anaemiaanaemia throughthrough bloodblood lossloss inin (Bilharzia) while victim is immersed inin infectedinfected water. stool and urineurine Sources: water infected by contaminated Prevention: Non-contamination of water. faeces and urine.urine. Certain streamsstreams andand LimLimitedi ted time inin and then a very briskbrisk rubrub downdown ppoolsoo l s are known reservoirs.reservoirs. There are many with a roughrough toweltowel ofof alla ll bodybody surfacessurfaces others. Health education a­ TetanusTetanus Endemic Clostridium tetani.tetani. Reservoir isis inin Of importanceimportance toto forestryforestry workersworkers whowho areare CO infected animals andand man.man. liable to punctures andand other wounds and I Immediate source of infection:infection: soil,soil, may well be inin infectedinfected areasareas dust, animal and human faeces.faeces. Prevention: Anti-tetanusAnti-tetanus toxoidtoxoid andand treatmenttreatment Enters thethe body throughthrough injury,injury, oftenoften ifif wounds contaminated with soilsoil oror faecesfaeces trivial.

Tropical Common Abrasions andand cuts.cuts. Abrasions should be cleanedc l eaned andand coveredcovered asas ulcers soon as possiblepossible (provision(provision ofof goodgood diet,diet, washingwashing facilitiesfacilities andand first-aidfirst-aid servicesservices hashas abolished tropical ulcersulcers fromfrom labourlabour forcesforces of well-run estates)estates)

Tuberculosis Very common Infection spread by droplets andand Health education: coughingcoughing coveredcovered -- avoidanceavoidance contaminated dustdust andand byby coughing,coughing, of spitting.spitting. Treatment ifif chestchest complaintcomp l aint spitting and poor housing (over-crowding(over-crowding -- suspected. Massive eradicationeradicat i on veryvery difficultdifficult all oneone room).room).

Source: Oseni and Ward, 19721972 inin FAO,FAO, 1976:1976: HarvestingHarvesting man-mademan-made forestsforests inin developingdeveloping countries.countries. - 69 -

3.2 Technological and Organizational Factors In Section 3.13.1 "Biological"Biological and Physical Factors", the focus was on factors which mainly originateoriginate fromfrom naturenature itself.itself. In this section, man-made factors,factors, which areare ofof greatgreat importanceimportance forfor thethe working environment in forestry, will bebe dealtdealt with.with. In particular, the harmful physical effects of different commoncommon technologiestechnologies suchsuch asas thethe noise andand vibration from will bebe described.described. The work organization isis (not(not inin all,all, but in many cases)cases) aa resultresult ofof thethe chosenchosen technology.technology. At least it is never independent of thethe technology.technology. The organizational factorsfactors will,will, however,however, be only briefly discussed, primarilyprimarily when thethe organizationorganization ofof work could be seen as an example ofof aa preventivepreventive measuremeasure againstagainst healthhealth problems.problems.

3.2.1 Design, use and maintenance of toolstools and machines In Section 2, mention was made of the importanceimportance of appropriate design, working techniquestechniques andand maintenance of toolstools asas aa means ofof reducingreducing physical workload and energyenergy requirementsrequirements as well as avoidingavoiding staticstatic work postures.

Starting with the design, the first requirementrequirement should be a design which isis bothboth safesafe andand efficient.efficient. There should not bebe obviousobvious risks of accidents andand work-related diseases,diseases, oror unnecessaryunnecessary fatigue.fatigue. We can take the simple example ofof a wooden handle ofof aa tool,tool, e.g.e.g. anan axe oror a planting hoe.hoe. To avoid accidentsaccidents thethe followingfollowing shouldshould bebe considered:considered:

. the handle should be fitted to the axehead or inin such a way that it does not fallfalloff off duringduring work;work;

the handle should have a knob at the end so as to give a better grip and toto avoidavoid slipping;slipping;

the material should be strong enough to stand the stress and not break easily.easily.

To avoid static work, uncomfortable work postures and inefficiency:inefficiency:

the shape of thethe handle shouldshould fitfit thethe gripgrip ofof thethe humanhuman hand,hand, e.g.e.g. have an ovaloval shape;shape;

the handle shouldshould absorb shocksshocks which arisearise whenwhen thethe axeaxe hitshits thethe tree or thethe hoehoe thethe ground.ground. With an S-shapeS-shape thethe shocksshocks will onlyonly bebe partly transmittedtransmitted toto thethe handshands or wrists;

the length and weight ofof thethe handlehandle shouldshould bebe appropriateappropriate forfor thethe type of work toto be done andand toto thethe heightheight ofof thethe worker.worker •

•4 1 - 70 -

1 , i- i e

Figure 23. An ergonomic design of an axe handle: the S-shape will help to absorb shocks, the oval shape will fit the grip of thethe hand, the knob at the end will prevent slipping,slipping, and the lengthlength will be appropriate forfor thethe particularparticular user.user. --71-71 -

Tools also havehave toto bebe usedused inin thethe proper way using thethe correctcorrect working technique.technique. ThisThis willwill bebe discusseddiscussed furtherfurther inin SectionSection 5.2.1.A,5.2.1.A, Appropriate technology.technology.

The samesame appliesapplies toto maintenance.maintenance. A tool which is both ergonomically designed andand usedused byby thethe workerworker withwith thethe correctcorrect working technique,technique, will still be a poor tooltool ifif poorlypoorly maintained.maintained. A bowsaw with a bladeblade which isis not sharpened,sharpened, oror isis sharpenedsharpened inin thethe wrong way, will requirerequire much more of the worker's energy and time thanthan a well-maintained saw, when doing the same amount ofof work.work. In many cases a poorly maintained tooltool willwill increaseincrease accident risksrisks andand healthhealth problemsproblems asas well.well.

It will not be possible toto go intointo detail concerning the design, use and maintenance ofof thethe various tools,tools, machines oror otherother equipmentequipment used inin different forestryforestry activities.activities. The intention at thisthis stagestage isis toto stressstress the importance of these aspects and to recommend further studies and training inin thethe subject.subject. Good books on maintenance of toolstools exist, for instance, referencesreferences 5757 andand 22.22.

3.2.2 Noise

The development ofof technologytechnology usedused inin forestryforestry hashas beenbeen accompaniedaccompanied by an increased number of noise sourcessources and higher noisenoise levels.levels. In many countries, where mechanized logginglogging methods have been introduced,introduced, noisenoise isis looked upon as one of thethe big problemsproblems inin thethe working environmentenvironment forfor forest workers.

The harmful effects ofof noise areare relatedrelated not onlyonly toto aa physiologicalphysiological loss of hearing, but toto increasedincreased accident riskrisk as well asas psycho-physiological effects.effects.

Individual reactions to exactly the same noise can vary between individuals depending on theirtheir different attitudes toto thethe particular soundsound source. No matter whether thethe soundsound isis appreciated oror not,not, itit maymay causecause aa loss of hearing when the level isis tootoo high and exposure tootoo long.long. Therefore it is necessary to make objective measurements of thethe noise toto know whether it is harmful or not and when preventive measures shouldshould be taken.

Sound

Sound is a mechanical disturbance propogated asas aa longitudinallongitudinal wave motion inin air or another elasticelastic oror mechanicalmechanical media,media, suchsuch asas waterwater oror steel.

Noise

In the following the definition used inin ILO Convention No. 148148 (1977)(1977) concerning the protection of workers against occupational hazards inin the working environment due toto noise,noise, vibrationvibration andand airair pollutionpollution willwill bebe used:used: "the term "noise" covers all sound which can resultresult inin hearing impairmentimpairment or be harmful toto health or otherwiseotherwise dangerous". -72-- 72 -

A.Ou/e.rOule_r- ear

Figure 24,24. The human ear.ear.

The human ear Organs forfor hearing and balance areare locatedlocated inin thethe human ear.ear.

The sound waves are caught by thethe outer ear (Fig.(Fig. 24A)24A) andand traveltravel through the auditory canal.canal. This canal is the inner part of thethe outer ear and ends with thethe earear drumdrum (Fi(F~. g. 24B).24B). The waves start to vibrate the ear-drum. From the ear-drum t e vibrationsvi rations are led to the three amplifying ear-bones: hammer,hammer, anvilanvil andand stirrupstirrup (Fi (Fi g.. 24C).24C). The vibrations pass through toto thethe cochleacochlea (Fi(Fig. g. 24D).240). TheluidThe fluidf in the cochlea affectsaffects thethe hair-cells. There are more tthan an 20,000 hair-cells and they are the beginning of thethe auditory nervenerve (Fig.(Fig. 24E).24E). The auditory nervenerve transmitstransmits the signals to the brain and the brain interpretsinterprets them as sounds.

When thethe hair-cellshair-cells areare exposedexposed toto veryvery strongstrong movementsmovements theythey mightmight be damaged - temporarilytemporarily oror permanently.permanently. HowHow noisenoise affectsaffects thethe humanhuman beingbeing will be discussed later,later, butbut firstfirst somethingsomething will bebe saidsaid aboutabout thethe physical characteristics ofof sound.sound.

Physical Characteristics ofof SoundSound

There are two basic characteristics ofof sound,sound, namely:namely: soundsound pressurepressure level, and frequency oror pitch.pitch.

Pressure - - - - Sound propagates as wave motions, e.g. inin thethe air. TheThe airair particlesparticles nearest to thethe soundsound sourcesource are firstfirst setset inin motion.motion. The motion is then spread to air particles further away fromfrom the source. In this way therethere will be small and regularregular fluctuationsfluctuations ofof thethe airair pressure,pressure, whichwhich willwill affect thethe ear-drum.ear-drum. - 7373 -

These fluctuations ofof thethe airair pressure are called "sound"sound pressure" and can bebe measured.measured.

To measure the soundsound pressure itit isis essential to describe thethe soundsound level. The measure for sound pressure (Pascal, PalPa) does not, however, give the idea of how variations of thethe sound level are experienced by the human ear. Hearing follows a logarithmic curve of intensity,intensity, which isis thethe case also for many other physiologicalphysiological sensations.sensations. Therefore a logarithmic unit, thethe decibel (dB)(dB) hashas beenbeen devised.devised.

The number of decibels gives the sound pressure level, comparedcompared to a reference level, zerozero dB.dB.

The scale isis logarithmic.logarithmic. A soundsound with anan intensityintensity 1010 timestimes stronger than 9hepe referencereference levellevel isis saidsaid toto bebe 1010 dB.dB. AtAt 9090 dBdB thethe soundsound pressure isis 1010 = 1,000,000,000 (one(one thousandthousand million) timestimes strongerstronger thanthan the lowest audible level.level. The logarithmic scale raisesraises problems when adding or subtracting different soundsound pressurepressure levels.levels. For example, if the number of noisenoise sources is doubled, the pressure level will rise by +3 dB. If the number is increased 10 times, thethe pressurepressure levellevel willwill riserise byby +10+10 dB.dB. Consequently, if a machine's soundsound pressure levellevel isis doubled fromfrom anan original 70 dB, itit will countcount 7373 dB - not 140 dB.

Regardless of thethe initialinitial soundsound pressurepressure level,level, aa change'change ofof e.g.e.g. 33 dB will havehave thethe samesame effecteffect onon howhow thethe humanhuman earear experiencesexperiences thethe sizesize ofof thethe change. An increaseincrease ofof 1010 dBdB givesgives thethe subjectivesubjective impressionimpression ofof approximately a doubling of thethe soundsound pressure level.level. Loudness is,is, however, a function of both intensityintensity of thethe soundsound andand thethe frequencyfrequency (the(the number of vibrations per second).second).

Frequency

The number of fluctuationsfluctuations perper secondsecond ofof thethe airair pressurepressure givesgives thethe pitch of the sound, and isis expressed inin herz (Hz).(Hz). (Previously itit was given inin cycles/sec.)cycles/sec.)

Frequencies between 16-20,000 Hz are the normal hearing range.range. The human ear, when normal,normal, cancan detectdetect soundssounds withinwithin thatthat range.range. Frequencies below 2020 Hz are called infrasound, and above 20,000 HZ,Hz, ultrasound.

Normally, a sound isis aa mixture ofof many frequencies,frequencies, andand cancan bebe classified as wide-band (incorporating(incorporating a wide rangerange of frequencies),frequencies), oror narrow-band (incorporating(incorporating onlyonly aa fewfew frequencies).frequencies). The combination of frequencies isis known asas thethe spectrumspectrum ofof thethe sound.sound. A sound of a certain volume isis experiencedexperienced byby thethe humanhuman earear asas lessless loudloud whenwhen thethe frequencyfrequency isis low.

Sound pressure levels areare measured inin dB, andand soundsound levelslevels areare measured inin dB(A), dB(B) oror dB(C).dB(C). The indices A, B and C show for which frequencies the sound pressure level has been weighted. It is weighted by the use of a filter on the measuring instrument,instrument, filteringfiltering outout certaincertain frequencies. When measuring noisenoise atat workplaces, thethe (A)(A) filterfilter isis used,used, measuring thethe noise inin aa similarsimilar wayway toto howhow itit affectsaffects thethe humanhuman ear.ear. The ear is,is, as mentioned earlier, lessless sensitivesensitive toto certaincertain frequencies.frequencies. - 7474 -

The volume in dB(A) and the effect on human beings of SOMEsome commonCOIlU1\on sounds are shown inin TableTable 5.5.

As shownshown inin TableTable 5,5, thethe thresholdthreshold forfor pain, with normal hearing, is in the range of 110-130 dB. Pain is not, however, a sufficient warning signal to avoid damage toto hearing. The critical level for hearing damage, when exposed 8 hours a dayday for several years, isis 8585 dB(A).dB(A). Exposure to levels below 85 dB(A) will rarely lead toto lossloss ofof hearing.hearing. At 8585 dB(A),dB(A), hearinghearing maymay bebe damaged.damaged. For an estimated level of 90 dB(A) or more, damaged hearing is to be expected from a daily exposure timetime of 8 hours or less.

It is not possible "to get used to" noise, in the sense that a high noise level will notnot bebe harmfulharmful inin thethe longlong term.term. Ears must be protected against noise, otherwise a loss of hearing will result.

Effect of Noise on Human Beings

Noise may affect human beings inin a number of different ways, and not only their hearing capacity.capacity. The effects cancan be divided intointo threethree groups:groups: (a) effects on hearing capacity - temporarytemporary or permanent effects (b) effects on other parts of thethe body - direct or indirectindirect effects (c) mental and socialsocial effects - effects on safety and efficiency.

(a) Hearing loss depends on the intensityintensity of the noise, the frequency value and the duration of exposure

Hearing loss is the difference between the audibility threshold and the standard referencereference zero at each frequency as defined in International standardStandard ISO 389-1975.389-1975. Impaired hearing isis when thethe hearinghearing lossloss exceedsexceeds aa designated criterioncriterion - commonlycOIlU1lOn1y 2525 dB,dB, averagedaveraged fromfrom thethe thresholdthreshold levelslevels at 500, 1,0001,000 andand 2,0002,000 Hz.Hz.

When hearinghearing lossloss isis thethe resultresult ofof prolongedprolonged exposureexposure toto noise,noise, thethe hair cells inin thethe innerinner ear have beenbeen damaged, andand thethe injuryinjury isis broadlybroadly speaking irreversible.

The hearing loss can also be the resultresult of very intense,intense, or explosive sounds. In such cases the eardrum can rupture. The structures of the middle andand innerinner earear cancan alsoalso bebe damaged.damaged. The hearing loss can also be temporary; a-so-calleda·so-called noise-induced temporary thresholdthreshold shift.shift. A loss of hearing may occur fromfrom exposure toto intense noise but the hearing capacity recoversrecovers after a period of time spent in silence. The extent of the hearing recoveryrecovery varies, individual differences andand thethe typetype ofof exposureexposure areare factorsfactors affectingaffecting thethe recovery.recovery. - 75 -

Table 5.5. Sound levels and examples of noise sources andand the effects on human beings.

Sound level Example of source of noise Effects on man inin dB(A)

o0 Threshold for hearing 10 Rustling of leaves 30 Whispering 50 Low conversation 60 Normal conversation 70 Private carcar SpeechrnaskingSpeechmasking

80 Loud shouting - 1 metre Threshold for physical discomfort

90 FramesawFrarnesaw Damaged hearing (at 8 hrs exposure daily)daily)

100-110 Chainsaw Damaged hearing (at(at ca.ca. 11 hrhr -- ca. 4 min. dailydaily exposure)exposure)

110-130 Propeller , wood Threshold of pain for chipping machine normal ears

above 130130 Risk of mechanical damage - 7676 -

(b) Effects on other parts of the body

Throughout thethe animal kingdomkingdom thethe sensesense of hearing isis primarily an awake system. This basic function still remains also in human beings.beings. WhenWhen steepening the acoustic sense isis a most effective awaken from sleep. Laboratory tests have shown that noise also affects the autonomous nervous system. Examples of such effects are: raised blood pressure, increased pulse rate,rate, constrictionconstriction ofof capillarycapillary bloodblood vessels, increasedincreased muscular tension and dilationdilation ofof pupils.pupils. The intestinesintestines and endocrine glands are also affected. These reactions are relatedrelated toto stress.stress. They are examples of reflex responsesresponses aiming at preparing the organism for facing a possible danger by being readyready forfor fight,fight, flightflight oror defence.defence. TheseThese reactionsreactions areare also influenced byby socialsocial andand culturalcultural factors.factors.

(c) Mental and socialsocial effects and effects on safetysafety and efficiency

otherOther effects thanthan reflexreflex responsesresponses of thethe autonomous nervous systemsystem and loss of hearinghearing areare moremore difficult toto prove.prove. Effects such ,as fatigue,fatigue, annoyance, non-specific healthhealth disordersdisorders andand effectseffects onon mentalmental healthhealth areare aso influenced byby social,social, culturalcultural andand subjectivesubjective factors.factors. The factors will affect individualindividual reactionsreactions toto thethe samesame noise.noise. Not only isis thethe levellevel of sound important,important, butbut alsoalso otherother characteristicscharacteristics suchsuch asas thethe content,content, e.g. whether thethe soundsound providesprovides aa message oror not;not; ifif itit isis predictablepredictable oror unexpected; and ifif itit isis aa steadysteady oror non-steady-statenon-steady-state noise.noise. Noise with negligible smallsmall fluctuationsfluctuations ofof levellevel duringduring thethe periodperiod ofof exposureexposure isis steady. A non-steady-statenon-steady-state noisenoise shiftsshifts significantly,significantly, e.g.e.g. fluctuatingfluctuating noise, intermittentintermittent noisenoise oror impulsiveimpulsive noise.noise. In particular, impulsive noise (i.e.(i.e. noise of very shortshort duration, atat aa levellevel significantlysignificantly aboveabove the background noise andand separatedseparated byby shortshort intervals)intervals) shouldshould bebe takentaken intointo account asas beingbeing harmful.harmful.

When thethe noisenoise levellevel hindershinders communicationcommunication betweenbetween workmates,workmates, itit willwill lead to socialsocial isolationisolation atat work.work. Investigations have shownshown that a reductionreduction ofof noisenoise isis commonlycommonly accompanied by a decrease inin errors,errors, andand anan increaseincrease inin production.production. The effects on efficiency are,are, however,however, difficult toto measuremeasure andand maymay varyvary withwith the situation, and subjectivesubjective uncontrolleduncontrolled factors.factors. Generally, noise is more disturbing, eveneven atat lowerlower levels,levels, when performingperforming aa mentalmental activityactivity rather than physical work.

Noise cancan alsoalso interfereinterfere withwith speech.speech. When the speech level exceeds the noise level by 1010 dB therethere will bebe nono interference.interference. When the difference isis less,less, thethe voicevoice mustmust bebe raised,raised, whichwhich isis tiringtiring andand maymay leadlead to misinterpretation. When thethe noise levellevel isis soso highhigh thatthat warning shoutsshouts or signals are masked itit cancan leadlead toto accidents.accidents. l - 77 -

Noise controlcontrol

The general principle forfor noise control isis thatthat preventive measures should be borne inin mindmind alreadyalready atat thethe designdesign stagestage ofof aa workplace,workplace, machine, tooltool oror equipment.equipment. To make corrections afterwardsafterwards isis usuallyusually moremore expensive, less efficient and may even raiseraise new problems in the production process.

The followingfollowing areare somesome waysways ofof control:control:

Eliminate or minimize noisenoise production by choosingchoosing alternative methods, designs,designs, equipmentequipment andand materialsmaterials (e.g.(e.g. useuse aa bowsawbowsaw insteadinstead of a chainsaw whenwhen treestrees havehave smallsmall diameters).diameters). Before purchase, thethe noise level requirementsrequirements shouldshould be discussed with manufacturers.

Prevent propagation, amplification and reverberationreverberation of noise. Many noise sources, suchsuch as motors inin operation, not only produceprOduce airborne noise, but thethe noise cancan spreadspread throughout thethe whole building, by taking different paths.paths. Such noisenoise sources should be installed withwith vibration-damping bases,bases, isolatedisolated fromfrom thethe floorfloor andand walls. The prevention of propagation of air- and structure-bornestructure-borne noise should be taken intointo account inin thethe planning and design of buildings, and in the spacing andand distributiondistribution ofof workplaces.workplaces. For example, noise sources which are unavoidable may be placed inin an isolatedisolated roomroom or area to minimize thethe number of workers exposed toto them.them. Prevention of noise propagation shouldshould be done near thethe sources.sources. The noise may be enclosed,enclosed, completelycompletely oror partially.partially. Sound barriers,barriers, sound-absorbing linings or panels inin thethe ceiling may be installedinstalled to reduce part ofof thethe noise,noise, itsits reflectionreflection andand echoecho effects.effects.

A person working near aa noise sourcesource isis mainly affected by thethe noise coming direct fromfrom thethe source.source. Therefore, thethe mostmost efficientefficient wayway ofof reducing thethe noisenoise isis atat thethe sourcesource itself.itself.

Adequate maintenance ofof machinesmachines andand equipmentequipment maymay alsoalso reducereduce thethe noise levellevel considerably.considerably.

When all effortsefforts toto controlcontrol noisenoise byby usingusing alternativealternative techniquestechniques andand methods, appropriateappropriate designdesign ofof buildingsbuildings andand equipmentequipment andand properproper installation and maintenance of machines, fail,fail, or ifif thesethese methods are not applicable,applicable, thethe workersworkers needsneeds constantlyconstantly toto wearwear earear protectors, andand thethe durationduration ofof exposureexposure toto noisenoise shouldshould be~limited. limited.

The latterlatter twotwo alternativesalternatives areare thethe onlyonly meansmeans ofof protectionprotection forfor chainsaw operators.operators. Today, all chainsaws have noise levelslevels which farfar exceed 8585 dB(A).dB(A). This situation is likely to continue inin thethe foreseeable future.

The length ofof timetime ofof exposureexposure cancan bebe limitedlimited byby modifyingmodifying thethe workwork organization and applying job-rotationjob-rotation andand job-enlargement.job-enlargement. A silentsilent environment should also be maintained during breaksbreaks fromfrom work andand atat mealtimes. - 78 -

Audiometry -- MeasuringMeasuring andand AssessingAssessing ofof Hearing:Hearing:

As already stated, the human ear is more sensitive to sound levels of certain frequencies.frequencies. It is most sensitive in thethe 1,000-4,000 HzHz range. This is also the most importantimportant frequency inin interpreting human speech.speech. A critical factorfactor inin interpretinginterpreting speechspeech isis the correct perception of thethe consonants.consonants. Consonants are pitched at higher frequencies than the vowels, which are mostly pitched below 1,000 Hz.Hz.

It may take up to 10-15 years toto developdevelop hearinghearing damage,damage, unlessunless thethe damage has been caused by, for example, an explosion or riflerifle shot near the ear. In the early stages of deafness caused by industrial noise, only the hearing of higher frequencies (in(in the 4,000 Hz range) is affected, and the individual will hardly noticenotice thethe lossloss ofof hearing.hearing. Itit can, however, be measured. If the daily noise exposure continues, the progressive loss of hearing will eventually reach the lower critical frequencies. Difficulties in understanding a conversationconversation willwill occuroccur inin thethe 300-3,000300-3,000 HzHz range.range.

The technique forfor measuring hearing - how the ear and brain perceive sound - is called audiometry.audiometry.

Regular audiometric examinations shouldshould bebe ca~riedcavied outout amongamong workersworkers exposed to daily high-level noise.noise. The purposes ofof'audiometric audiometric examinations are:are:

- to identify individualsindividuals showingshowing signssigns ofof hearinghearing loss;loss; - to get a screening of the hearing status of the workforce and its changes overover time;time; - to assess thethe effectiveness ofof noisenoise controlcontrol measures.measures.

The audiometric measurements should preferably be part of a noise control programme and include detailed noise surveys of all workplaces as well asas individualindividual noise dose measurements (dosimetry).(dosimetry). Assessment of noise conditionsconditions may leadlead toto different measuresmeasures being taken, applying engineering or administrative methods; provisionproviSion of ear protectors and informationinformation toto exposedexposed workers.workers.

3.2.3 Vibration

vibration,Vibration, like noise, isis thethe transmissiontransmission of mechanical energyenergy fromfrom sources of oscillation. When talkingtalking about "vibrations""vibrations" one usually means oscillation of suchsuch aa frequencyfrequency and amplitude thatthat itit isis perceptible with thethe sensesense ofof feeling.feeling.

Vibrationvibration is described byby itsits accelerationacceleration (m/s2(m/s2),), itsits frequency (oscillations per second = Herz (Hz))(Hz» andand typetype ofof vibration,vibration, e.g.e.g. sinus vibration.

Vibrations transmitted toto thethe humanhuman body are generally divideddivided intointo two groups: whole body vibration or local vibration (mainly(mainly hand-arm vibration), mainly depending on thethe point of transmissiontransmission toto thethe body and the frequencyfrequency ofof vibration.vibration. It is, however, often difficult toto distinguish where the border isis between thethe twotwo groups.groups.

The effects of vibration onon man cancan vary fromfrom feelingfeeling slightlyslightly sicksick (e.g. seasea sickness,sickness, travel sickness) to severe physical injuries (vascular spasm, back trouble).trouble). The problems may start after even a short period of exposure. Vibrations with different frequenciesfrequencies cause resonanceresonance phenomena inin different parts of thethe body.body. - 79 -

Head Ca 25 71z ,Eyeeye bd/l 5 30-QOHz30-qo Hz Shoulder- -4/-5-Hz- Chest SpInalSpina/ caMHzca 10 Hz column~/1I",n --- 10-IZHz10-12Hz PlaphragntPiarhra!lm 10-tZHZW-12. itiz

Abc/omezii 4 Hz 1-land}/qncl 6V-20050-ZOO HzHz --I-

LegsLe9S --1---- varyingvan,ing~'" Away z ca 2Z Hz '.j,lVil" 1/, lie_nibent kn-sknees 10lo more"'on! away'!'on :zo2o Hzliz ,.,i'" SiewighéSlra'9"{ LegsLegs

Figure 25.25. Frequencies for resonanceresonance inin different parts of thethe body inin Zz direction. - 80 -

Whole Body Vibration

At higher frequencies thethe vibration will causecause moremore severesevere disturbances. The disturbances are oftenoften groupedgrouped inin thethe followingfollowing way:way:

- discomfort (physical(physical and/orand/or psychological)psychological) - disturbances of functional capabilities - injuries (reversible(reversible and/or irreversible)irreversible)

Besides the physiological disorders vibration may also lead to tiredness andand lowerlower workwork output.output.

The nature and magnitude of the effects depends mainly on the vibration's frequency,frequency, intensityintensity and direction, on the duration of exposure, body posture and part of body inin contact with the sources of vibration.

Wholewhole bodybody vibrations may affectaffect aa sittingsitting oror standingstanding person throughthrough the buttocks and feet,feet, e.g. while operating a tractor or standing on a vibrating floorfloor or foundation, forfor instanceinstance inin a .

Vibrations betweenbetween 1-201-20 HzHz areare particularlyparticularly disturbing and tiringtiring and these are also the frequencies which dominate inin vehicles and industry.industry.

The vibration will then pass through the whole body, with almost no lessening ofof intensity.intensity. This regardless of the vibration's point of application onon thethe body.body. Frequencies of 4-54-5 HzHz andand 8-128-12 HzHz alsoalso causecause resonance phenomena which makemake themthem particularlyparticularly harmful.harmful.

In forestry, machine operators frequently complain about back and neck troubles inin connectionconnection withwith wholewhole bodybody vibrations.vibrations. Other common complaints are pain in the chest and stomach, muscle cramps and breathing difficulties.

Exposure to whole body vibrations also affects the centralcentral nervous system and may disturb the metabolic processes and also increaseincrease energy losses of thethe organism.organism. High levels of whole body vibration may also damage internal organs.organs. Even sight may bebe affected.affected.

Hand-ann-vibrationsHand-arm-vibrations

Hand-arm vibrations are high-frequency vibrations transmittedtransmitted toto the worker fromfrom powerdrivenpowerdriven handtools.handtools. In forestry this refersrefers toto chainsaws.chainsaws.

The vibrations affect thethe tactiletactile sensesense of thethe fingersfingers andand hands. The phenomenon is known as "vibration-induced"vibration-induced white finger"finger" - VWF, with symptoms similar to Raynaud's phenomenon and Traumatic Vasospastic Disease - TVD.

The small intricate blood vessels inin thethe skinskin contractcontract andand thethe blood cannot circulate.circulate. This causes a discolouring of thethe fingersfingers and may also result in a temporary loss of thethe sense of touchtouch inin the fingers.fingers. Other types of vibration effects are injuredinjured nerves. This will appear as numbness and tingling feelings, often during thethe night. Bones, joints and even muscles cancan bebe affected.affected. Bone injuries appear as small hollows in the bones of thethe fingers,fingers, andand thethe injuriesinjuries inin jointsjoints andand sinewssinews appearappear asas inflammations. Often it will taketake several years before thethe injuriesinjuries appear. - 81 -

The initial symptoms are trivial,trivial, starting with tingling and/or numbness in thethe fingertips.fingertips. Later on, occasional blanching, withwith numbnessnumbness and pain, will occur inin one or more fingers, particularly during cold weather. In the later stages these attacks occur frequently, also when it is not cold.cold.

The attacks during later stages are accompanied by a reducedreduced ability to hold and control any object, such as working tools or the steering wheel of a car. Most individualsindividuals reachingreaching thethe laterlater stages have toto give up any job or activity involvinginvolving vibratingvibrating hand-heldhand-held tools.tools. In extreme cases ulceration may occur atat thethe fingertips,fingertips, sometimessometimes accompanied byby gangrene.gangrene.

Usually the first signsign of white fingersfingers occurs after regularregular exposure to vibration for an extended period of time (from(from weeks to many years)years).. Investigations show big individual differences in sensitivity, and that smoking habits may havehave anan influence.influence.

These symptoms can be graded according to a special scale shown below, for symptoms of Raynaud's phenomenonphenomenon after Taylor andand PalmearPalmear (1975).

VWF CONDITION OF DIGITS WORK AND INTERFERENCE STAGE oO No blanching of digits No complaints.complaints.

Ot Intermittent tingling No interferenceinterference with activities

Intermittent numbness Ii 0n Intermittent numbness " " " " " Blanching of one or more fingertips with or without tingling and numbness ii" " " " "

2 Blanching of oneone oror moremore Sliaht interferenceinterference withwith homehome fingers with numbness.numbness. andand-social social activities.activities. Usually confined toto winter. NONo interference atat work.work.

3 Extensive blanching. Definite interferenceinterference atat work,work, Frequent episodes. at home and with socialsocial Summer as well as winter.winter. activities. Restriction of hobbies.

4 Extensive blanching of most Occupation changedchanged toto avoid fingers; frequent episodesepisoaes­ further vibration exposureexposure in summer and winter. because of severityseverity ofof symptoms. - 82 -

combattingCombatting Vibrations

As inin thethe casecase of combattingcombatting noise, thethe prevention of harmful effects from vibrations will include different measures, which are mainly technical and organizational.

The firstfirst solutionsolution toto try shouldshould always be the elimination of the vibrations, forfor exampleexample byby choosingchoosing anan alternativealternative method,methOd, machine oror tool,tool, which does notnot generategenerate vibrations.vibrations.

When thisthis isis notnot possible,possible, aa reductionreduction ofof thethe vibration atat sourcesource should be tried by, for example, another design or better maintenance of the machine oror tool.tool.

Another alternativealternative isis toto preventrevent thethe vibrationsvibrations beingbein transmittedtransmitted from the machine or tool to man, by remoteremote control,contro, byy absorptionsorptlon or byy short-circuiting thethe vibration.vibration. The vibrations being transmittedtransmitted toto thethe worker cancan bebe reducedreduced byby different damping elements.elements. In the case of chainsaws, damping (rubber)(rubber) elements are placed between the engine unit and the handle unit. In addition, the handles shouldshould bebe coveredcovered withwith rubber.rubber.

Even in cases where measures have been taken to reducereduce the vibrations at the source ofof theirtheir transmissiontransmission toto man therethere maymay stillstill bebe aa needneed forfor the use of personal protectiveprotective equipment.equipment.

Personal protective equipment, such as gloves (of(of good quality) can be seen as an additional,additional, butbut insufficient,insufficient, dampingdamping elementelement betweenbetween thethe handgrip andand thethe worker'sworker's hand.hand. In a cold climate it is also importantimportant toto keep thethe handshands warmwarm andand dry.dry. (On somesome chainsawschainsaws usedused in cold climates, the exhaust gases areare ledled intointo thethe handles soso asas toto keepkeep thethe hands warm.)

There is evidence that the introductionintroduction of chainsawschainsaws with anti-vibration systemssystems has improvedimproved thethe situationsituation greatly.greatly. In spite of this, no chainsawchainsaw available todaytoday (1987),(1987), regardlessregardless ofof anti-vibrationanti-vibration systems, can be classified as "safe" as far as VWF is concerned.concerned. Because of this, but also because ofof thethe long-termlong-tel>n naturenature ofof thethe disease,disease, hand-armhand-arm vibrations will continuecontinue toto be aa problem forfor manymany chainsawchainsaw operatorsoperators forfor aa long time ahead.ahead. The Whitewhite Fingers disease has been well-known inin thethe industrialized and temperatetemperate countriescountries forfor decades.decades. In spite of this, no informationinformation was available as toto whether chainsawchainsaw operatorsoperators inin thethe tropicstropics sufferedsuffered fromfrom thethe disease. As coldcold isis knownknown toto provokeprovoke thethe problemproblem ofof VWF,VWF, thethe diseasedisease hashas been supposed toto be a problem particularlyparticularly forfor countriescountries with aa coldcold climate. A smallsmall studystudy inin thethe PhilippinesPhilippines (1984/85)(1984/85) however,however, gavegave indication that this is a problem also in tropical countries.

Since there is a riskrisk that available preventive measures includingincluding damping elements and gloves will proveprove inadequate,inadequate, itit maymay bebe necessarynecessary toto apply a daily exposureexposure limit.limit. This has already been introduced inin some countries, such as Japan, thethe NetherlandsNetherlands andand Czechoslovakia.Czechoslovakia. It may therefore be necessary toto changechange working routinesroutines andand toto introduceintroduce jobjob rotation to decrease thethe timetime ofof exposure.exposure. - 8383 --

When somebodysomebody isis toto bebe employedemployed on a jobjob where he or sheshe will be exposed to a lot of vibrations, informationinformation about the risksrisks shouldshould be given. Regular follow-upsfollow-ups should thenthen be another measure toto prevent problems.

Some advice toto thethe useruser ofof vibratingvibrating machines:machines:

- Use glovesgloves (and(and keepkeep thethe handshands warmwarm andand drydry inin aa coldcold climate).climate).

- Let the tooltool do thethe work andand applyapply as looseloose a grip asas possiblepossible - but without losing controlcontrol ofof thethe tool'stool's movements. The chainsawchainsaw should,should, for example, restrest as muchmuch asas possiblepossible onon thethe stem.stem.

- Avoid oror decreasedecrease thethe consumptionconsumption ofof tobacco,tobacco, asas nicotinenicotine willwill diminish thethe blood flowflow toto handshands andand fingersfingers and therebythereby make thethe problem worse.worse.

- Seek medical advice if attacks of white or bluish fingers occur or if long periods of tinglingtingling sensationssensations oror numbnessnumbness inin thethe fingersfingers occur.occur.

- Inform the supervisor inin casecase ofof abnormalabnormal vibrations.vibrations.

3.2.4 Harmful substances, e.g.e .. chemicals, solvents, gases,ases, smokesmoke and dustust

In this section an account will be given of how harmful substances in the working environment cancan affectaffect man.man. Examples of suchsuch substancessubstances areare chemicals, solvents,solvents, gases,gases, smoke,smoke, fumesfumes andand dust.dust. Every day new substances are introducedintroduced atat workplaces.workplaces. In most cases it has never been examined whether they are harmful oror not.not. Often investigations begin only after the workers showshow symptomssymptoms ofof diseases.diseases. Therefore all such substances should bebe handled withwith the greatest care, bearing in mind that they might be~rmf~.be harmful.

When the body isis exposed toto aa harmfulharmful substancesubstance overover aa longlong periodperiod ofof time or whenwhen the concentration is too high, the body's capacity to purify them willwill be insufficient.

The effects can either be acute (disappear(disappear after a certain time) or chronic (lasting).(lasting). Common symptoms ofof acuteacute effectseffects areare headache,headache, dizziness and vomiting. These cancan easilyeasily occur when using variousvarious solvents.solvents. ExposureExposure to solvents can also have chronic effects on the nervous system, causing increased fatigue, impaired reactionreaction time and memorization. Bigger amounts of the solvent will be storedstored inin thethe brain, forfor example,example, when:

the concentration in the air isis high thethe physicalphysical workloadworkload is big (the air intake willwill increase) thethe solvent is readily diffused or suspended in air thethe exposureexposure time is long.

There are three ways in which a dangerous substance can enter thethe body, as illustrated in FigureFigure 26.26. - 8484 --

Inhaling Skin contact Ingestion

Figure 26.26. Three different ways aa chemicalchemical cancan causecause injury.injury.

- it can be absorbed throughthrough the skin - it can be inhaledinhaled - it cancan bebe ingested.IT1Ajd. The substance can then have either a locallocal or a ssystemic stemic (so-called(so-called organic) effect, which happenshappens when thethe substancesubstance isis spreadspread byby thethe bloodblood further in the body where itit maymay affectaffect variousvarious organs.organs.

Skin contact Direct contact between the skin and a substancesubstance ofof a corrosivecorrosive nature such as acid, ammonia or lye may cause caustic injury.injuiK. InIn such a situation the skin should immediately be rinsed thorough1ythoroughly withwi plenty of water. Other substances may notnot causecause reactionsreactions soso quickly.quickly. IfIf thethe skinskin isis exposedexposed to e.g. solvents, detergents or coolants forfor somesome time,time, it may become irritated and a non-allergic eczemaeczema cancan develop.develop. 'fheThe skin becomes reddishreddish and itches.itches. It maymay become chapped and there may also be blisters and sores. The eczema may disappear if treated adequately or ifif thethe skinskin isis no longer exposed toto thethe irritant.irritant. The healing process may taketake aa longlong timetime -- up to severalseveral months.months.

SomeSome people acquire hypersensitivity to certain substances. After only a short time of exposure (some(some weeks) or after many years, an allerallergic ic eczema develops. Once the allergic eczema has developed, thethe person will aalways ways get thisthis reactionreaction toto thethe particularparticular substancesubstance eveneven whenwhen thethe quantityquantity is very small.small. One can never tell who will getget suchsuch anan eczema or how longlong it willwill take for it to develop. Substances which may causecause allergicallergic eczema are: chromium (can(can bebe foundfound inin e.g.e.g. cement,cement, leatherleather andand rust-proofingrust-proofing agents), nickel (can(can be foundfound inin many objects, e.g.e.g. keys,keys, tools,tools, coinscoins which are nickelplated) andand cobaltcobalt (e.g.(e.g. inin detergentsdetergents andand colourcolour pigments).pigments) • - 8585 --

If the eczema is of the allergic type the workerworker should not, in any way, be exposedexposed toto thethe harmfulharmful substance.substance. If it is a non-allergic eczema,eczema, protective equipmentequipment maymay bebe sufficient.sufficient.

Face-protection and gloves made of rubberrubber should be avoided because rdbberrubber is a material which oftenoften causescauses allergicallergic eczema.eczema. Plastic gloves will not causecause allergicallergic eczema.eczema.

At workplaces where substancessubstances which are known toto causecause allergicallergic eczema have toto be used itit isis importantimportant toto have very good facilitiesfacilities forfor washing oneself and forfor cleaning thethe protectiveprotective equipment after use.

Inhaling

The lungs as described in Section 2.1 take up oxygen and transfer it to thethe blood.blOOd.

When therethere isis notnot onlyonly oxygenoxygen butbut alsoalso harmful substances,substances, forfor example gases, fumesfumes and dust, inin thethe air,air, thesethese will also bebe inhaled.inhaled.

The effects can be either local - affecting the lungs only - or systemic/organicsfstemic!organiC - when thethe substancessubstances spreadspread toto different organs with the blood.b oOd.

Dust, which isis aa commoncommon problemproblem inin thethe wood-working industries,industries, cancan directly give only locallocal effects. Sometimes, however, there are otherother substances inin thethe dustdust whichwhich maymay enterenter thethe bloodblood andand givegive organicorganic effects.effects. Some wood species,species, particularly ofof thethe tropics,tropics, cancan causecause allergicallergic reactionreaction of the lungs with coughing and breathingbreathing difficulties, similarsimilar toto asthmaasthma oror hay-fever symptoms.symptoms. The smaller the dust particles, thethe more dangerous theythey are. Only very fine dust cancan enter thethe airsacsairsacs inin thethe lungslungs andand remainremain there.there. It is also more difficult toto protect oneselfoneself againstagainst smallsmall particles.particles. They are not so irritatingirritating as largerlarger particles andand thethe person isis usuallyusually notnot atat allall aware of inhalinginhaling them.them. The protective breathing equipment must then be of a high standard.standard. Chronic bronchitis may be a resultresult of working inin a dusty environment.environment. The victim will suffersuffer fromfrom heavy coughingcoughing inin thethe morning.morning. Particularlyparticularly when combined with smoking,smoking, thethe problemproblem cancan bebe severe.severe. As aa rulerule thethe problems of harmful substancessubstances becomebecome worseworse when combinedcombined with smoking.smoking.

Another exampleexample ofof dangerousdangerous substancessubstances inin thethe airair areare harmfulharmful gases,gases, for example ammonia andand vapoursvapours fromfrom acids.acids. They can be irritating and lead to coughing. The eyes will also be affected.affected.

Ingestion

The third way for a substance toto enterenter thethe human bodybody isis throughthrough thethe mouth. Dangerous substancessubstances handled byby thethe worker, andand leftleft onon thethe hands,hands, can enter the body when eating or smoking.smoking. Personal hygiene shouldshould bebe emphasized and will require good washing facilities.facilities. - 8686 --

Some types of harmfulharmful substancessubstances

So far the discussion has mainly concentrated on how the worker may be affected by a substance, e.g. the effect is acute or chronic, it is local or systemic/Organic,systemic/organic, and how the substance can enter the body (through the skin, lungslungs oror mouth).mouth).

To help recognizerecognize thethe risksrisks at the place of work this section will be devoted to a description of the harmful substances and some of their characteristics. The substances can be divided intointo threethree mainmain groups:groups:

1) harmful substancessubstances suspendedsuspended inin thethe air,air, e.g.e.g. dust,dust, smokesmoke andand gases;gases; 2) liquids, oils andand vapours,vapours, e.g.e.g. solvents,solvents, acidsacids andand bases;bases; 3) metals, e.g.e.g. nickel,nickel, chromiumchromium andand lead.lead.

In the forest and wood processing industries most harmful substances are found in groups 1) and 2) e.g. dust, liquids, oils, exhaust gases and vapours. Group 3)3) isis notnot coveredcovered inin thisthis publication.publication.

1) Harmful substances suspended in the air, e.g. dust, smoke and gases

As already mentionedmentioned thethe humanhuman bodybody cancan toto somesome extentextent protectprotect itselfitself against injuries. This capacity depends on the particles°particles' size, nature and concentration inin thethe airair andand alsoalso onon exposureexposure time.time.

The particles - if not very small - can be rejectedrejected or filteredfiltered out already in the nose oror bronchi.bronchi.

Some particles are of a very dangerous nature and may cause severe damage toto thethe innerinner organs.organs. This is the case with somesome metalsmetals andand metalmetal alloys, e.ge.g.. lead andand chromium.chromium. The concentration ofof thethe substancesubstance inin thethe air as wellwell as how long one is exposed to the polluted air are often decisive factors.factors.

Dust In the woodworkingwoodworking industries the main airborne particles causing health problems are wood dustdust ofof different sizessizes andand species.species. Dust may cause allergic reactions, toxic effects, respiratoryrespiratory diseases and cancer. AA more detailed discussion ofof dust asas aa healthhealth hazardhazard willwill bebe foundfound inin Section 6.7 "Wood"Wood Processing".Processing".

Gases

Gases can affect thethe bodybody inin differentdifferent ways.ways. Some gases irritateirritate the breathing organs or have a corrosive effect - irritant gases. Other gases are taken up by the blood and affect various internalinternal organs.

For certain gases one gets a warning signal, when breathing, by the sharp and irritating smell of the gas, while other gases lack both smellsmell and colour. These latter gases are particularly insidiousinsidious as theythey gradually impair thethe awarenessawareness ofof thethe danger.danger. One example of such a gas isis carbon monoxide in the exhaust gases from motor vehicles and power chainsaws. When exposed toto thesethese gasesgases underunder normalnormal outdooroutdoor conditionsconditions - 87 - with unlimited amountsamounts ofof freshfresh airair thethe worker isis not soso much affected. Underunder certain circumstances,circumstances, e.g.e.g. when using thethe chainsawchainsaw inin very dense forest with very little air velocity or in deep snow there is a risk of reaching high concentrationconcentration causingcausing effectseffects suchsuch asas headacheheadache andand dizziness.dizziness.

There are als6also other substances in the exhaust gases from the chainsaw which cancan affectaffect thethe worker.worker. Neither all thethe substancessubstances nornor theirtheir effects areare yetyet fullyfully known.known. Also thethe chain oil gases contain harmful substances which areare inhaledinhaled byby thethe chainsawchainsawoperator. operator.

2) Liquids, oils and vapours

At many work placesplaces solventssolvents areare used because of theirtheir ability toto destroy and dissolvedissolve greasesgreases andand fats.fats. This is also thethe casecase inin thethe forestforest and in forestforest industries.industries. The solvent evaporates and the vapours are inhaled. Because of the solvent's ability to be dissolved in or to dissolve other substancessubstances itit can be dissolved inin thethe blood. The solvent can then be transportedtransported toto differentdifferent organs.organs. Particularlyparticularly thethe brainbrain andand the central nervous system,system, which contain a lotlot of fat,fat, will attract the fat-dissolving solvents.solvents. The symptoms are dizziness, headaches,headaches, tiredness,tiredness, impaired ability toto understandunderstand andand toto reactreact fast.fast. All these symptoms could be factors increasingincreasing thethe riskrisk ofof accidents.accidents.

Solvents with aa lowlow viscosityviscosity areare moremore dangegous.dange ~ ous . They will spread faster inin aa closedclosed room.room. The higher the concentration in the air the bigger are thethe risksrisks andand thethe riskrisk will increaseincrease with time.time.

A heavyheavy physicalphysical jobjob leadingleading toto anan increasedincreased intakeintake ofof airair willwill alsoalso increase thethe riskrisk ofof injuries.injuries.

Solventssolvents enter thethe bodybody inin differentdifferent waysways (see(see FigureFigure 27).27).

CeniredC£mral nervous systemsy.steni

Figure 27. Solvents do not enter thethe bodybody throughthrough thethe lungslungs only.only. They may also enter throughthrough thethe cellscells inin thethe skin.skin. -88-- 88 -

Other harmful substancessubstances belonging to this group (2)(2) are acids and bases. They are of a corrosivecorrosive nature and may damage thethe skin as well as tli"i!'eyesthe eyes if inin direct contact.contact. They can also, inin thethe formform ofof mistmist fromfrom thethe acids and bases, causecause injuriesinjuries toto thethe lungslungs whenwhen breathing.breathing.

In forest industryindustry a number of different oils such as hydraulic oils are usedused for greasing andand otherother purposes.purposes. TheThe o~anoil canenter enter thethe bodybody when breathing, inin thethe formform ofof mist, vapour or smoke,smoke, throughthrough swallowingswallowing ifif personal hygiene isis poor andand throughthrough direct contact with thethe skin.skin. Oils may cause many different injuriesinjuries toto thethe lungslungs andand skin.skin. They may causecause eczema, allergies andand cancer.cancer. Also forestforest workers usingusing powerpower chainsaws,chainsaws, tractors and other machinery areare exposedexposed toto differentdifferent typestypes ofof oils.oils. It is particularly difficult forfor workers carryingcarrying out serviceservice and repairrepair work to protect themselves and many develop eczemas and allergies.

There are thereforetherefore many reasonsreasons forfor avoidingavoiding contactcontact with oils as much as possible. At many work places itit is possible toto use lessless harmful oils than isis thethe casecase today.today. workWork places or premises, machines, work methods and ventilation shouldshould also be arranged soso as toto avoid all unnecessary contactcontact withwith thethe oils.oils. The worker should nevernever keepkeep ragsrags oror cotton waste soakedsoaked withwith oiloil inin thethe pockets.pockets. Washing facilitiesfacilities shouldshould be within easy reachreach andand thethe workersworkers shouldshould bebe informedinformed aboutabout thethe necessitynecessity ofof washing hands andand armsarms beforebefore mealsmeals oror smokingsmoking andand eacheach timetime theythey getget oiloil on their skin.skin. Personal protective equipment should always be used whenwhen contact with oils isis unavoidable.unavoidable. To take immediate care of small woundswounds or cuts is particularly importantimportant when inin contact with oils soso as toto avoid inflammation.

There are also other chemicals used inin forestryforestry activities,activities, suchsuch as pesticides,~sticides, e.g. insecticides,insecticides, herbicidesherbicides andand fungicides.fungicides. PesticidesPesticides areare ooften ten used in forest nurseries, in seedling treatment and forfor thethe preservation ofof unbarkedunbarked timber.timber.

Pesticides inin forestryforestry are usually used diluted with water oror as spray powder (dust).(dust). The method of application is often a manual one using different types ofof portableportable devices,devices, suchsuch asas aa sprinklingsprinkling can,can, knapsackknapsack pressure sprayer, backpackbackpack powerpower sprayersprayer oror mistmist sprayer.sprayer. The pesticide tank is carried onon thethe worker'sworker's back.back. (It is also possible to spread the pesticides from aeroplanesaeroplanes oror byby tractor-operatedtractor-operated sprayers.)sprayers.) When using the manualmanual methods the exposure will mainly be through thethe respiratoryrespiratory tract (the lungs) but sometimes through the skin as well. The use of tractor-operated sprayers will usually reducereduce thethe exposure.

Workers handlinghandling pesticides,pesticides, particularlyparticularly inin manualmanual methodsmethods ofof application, cancan bebe exposedexposed toto ratherrather highhigh concentrations.concentrations. Examples of situations involving high riskrisk of exposure are: when weighing out and mixing the pesticides with e.g.e.g. water andand whenwhen fillingfilling thethe sprayer,sprayer, thethe worker will be exposed toto dustdust andand splashes.splashes. During thethe applicationapplication thethe risk is high of inhaling the pesticide vapour or of getting splashessplashes on the skin. Even when protective clothingclothing isis used, thethe pesticidespesticides maymay penetratepenetrate the clothes when carryingcarrying thethe equipment.equipment. When using portableportable sprayingspraying equipment the worker comescomes very closeclose toto thethe harmfulharmful chemicals.chemicals. It is very - 8989 --

important that a cornectcor~ct working method isis used as itit will reducereduce thethe risksrisks considerably. The riskrisk of skinskin exposure isis also high during repairrepair and cleaning of thethe equipment unless appropriate protective devices and methods are used.

As mentioned above,above, pesticidespesticides cancan also be distributeddistributed inin a powderedpowdered form. The powder (dust)(dust) cancan enterenter thethe bodybody throughthrough thethe lungs.lungs. IfIf thethe chemical is instead manufactured inin cakes, pellets or granules, the risksrisks through inhalationinhalation willwill bebe considerablyconsiderably reduced.reduced.

Many pesticides areare slightlyslightly toxic.toxic. The riskrisk of acute poisoning is known to be highhigh forfor somesome pesticides.pesticides. They may also cause toxic and allergic skin symptoms, as well as irritationirritation of thethe mucous membranes. There is insufficient knowledge about long-termlong-term effects, suchsuch as cancer and genetic injuries.injuries. Experimental observations carried out on whether pesticides cause injuryinjury toto thethe unborn childchild or affect pregnancy, callcall forfor caution, however.however. As many of the workers employed in nurseries and forest plantation areare youngyoung women,women, itit isis wise toto protectprotect pregnantpregnant andand breast-feeding women inin particular fromfrom all exposure.

Preventive measures

At the national level

Some countries, e.g.e.g. USA, thethe Soviet Unionunion andand most EuropeanEuropean countries, have accepted hygienic maximum limits forfor chemicals inin working lifelife.. The concentration ofof aa dangerous substancesubstance inin thethe airair isis not allowedallowed to exceed a maximum permissiblepermissible limit.limit. The use of somesome dangerousdangerous chemicalschemicals (e.g. DDT)DDT) is totally prohibited.

Lower limits are statedstated forfor more dangerous substances.substances. If the limits are exceeded there are big risksrisks to thethe workers' health according toto thethe scientific investigations thesethese threshold limit values (TIN)(TLV) are basedbased on.

It should be the responsibilityresponsibility atat thethe nationalnational level:level:

- to follow developments regarding the marketing of chemicals and otherother dangerous substances which are used inin working life; - to control manufacturers, importers and other deliverers of dangerous substancessubstances inin thethe country;country; - to spread and develop a register of chemicals and other dangerous substances present inin thethe country;country; - to investigate and document the risksrisks to health and the environment of these chemicals and substances; and - to give information to the end-users of products containing chemicals and dangerous substances.substances. Essential information to give to the end-users is:is:

commercial name of thethe product;product; classification according to how dangerous thethe substance is;is; the risks to health of both short- and long-term exposure toto thethe product; - 90 -

preventive measures toto take;take; type of personal protectiveprotective equipmentequipment toto use;use; appropriate measures toto take inin case of an accident or other emergency situation,situation, e.g.e.g. fire;fire; handling ofof wastes; name of and concentration of the dangerous (active)(active) substance(s) in the product; purpose of use; and name and address of the manufacturer or importer with responsibilityresponsibility for the information on product content.content.

~t_~e_e~t~rEris~At the enterprise levelle~el The individual worker handling dangerous chemicals and other substances must receivereceive informationinformation about:about:

the risksrisks toto health;health; how to protect himself or herself e.g. what protective clothing and equipment toto use,use, howhow toto wearwear itit andand keepkeep itit clean;clean;

. what toto dodo inin casecase ofof anan accidentaccident oror emergency;emergency;

. how to store and transport thethe substances;substances; and

. how to treattreat wastes.

In addition to individual information,information, which should be both written (in easilyeasily understood language, with illustrations)illustrations) andand verbal,verbal, there should also be information at the workplace. It should be easy to find when working with thethe substances,substances, e.g.e.g. postersposters andand brochures.

The workplace should be equipped with all the necessary technicaltechnical measures to eliminate or reducereduce risks,risks, suchsuch asas appropriate ventilation,ventilation, washing facilities,facilities, medical service,service, andand thethe workers shouldshould bebe providedprovided with suitable personal protectiveprotective equipment,equi.pment, e.g.e.g. gloves,gloves, shoes,shoes, apronsaprons andand respiratory protective devices. The first and most importantimportant action toto take will, however, always be to try to find out if the dangerous substance could be replacedreplaced by one which isis lessless harmful.harmful .

3.2.5 ventilationVentilation and draught The need for ventilation and thethe occurrence of draught isis not aa problem inin forestryforestry inin normalnormal outdooroutdoor activities.activities. It may, however, be a problem in e.g. thethe wood-processing industryindustry andand inin tractortractor cabins.cabins. This section will therefore dealdeal withwith technologicaltechnological factors.factors. The outdoor climate waswas dealt with in Section 3.1.3.1. Biological and Physical Factors.Factors. ventilationVentilation The primary reasonreason forfor ventilating a roomroom at thethe workplace isis toto ensure that the air in the roomroom isis of such quality as to avoid any adverse effects on the health, well-being or working capacity of thethe workers. The composition of the air in a roomroom isis affected by the people inin thethe roomroom and by the ongoing activities andand processes.processes.

The human being will, forfor example, consumeconsume oxygen, evaporateevaporate humidity,humidity, and maymay also spread bacteria and other microbes toto thethe airair fromfrom thethe air passages when sneezing,sneezing, coughingcoughing andand talking,talking, andand alsoalso fromfrom thethe skin,skin, hairhair and clothes. --91-91 -

Other sources ofof air pollution are chemical or physical processes going on in the room. These processes will be decisive in how comprehensive the ventilation shouldshould bebe andand howhow toto arrangearrange it.it.

Big glass windows facingfacing thethe sun may also add heat to the roomroom to the eXextent,tent that ventilation will be necessary to cool the air. When a roomroom is ventilated itit isis suppliedsupplied withwith sufficientsufficient quantities ofof freshfresh air toto bring about a sufficient dilutiondilution ofof thethe unhealthyunhealthy oror hothot air.air.

ventilationVentilation can be attained by natural movement of air using the differences between the indoorindoor and outdoor air temperatures, and using windpower as thethe impellingimpelling force.force. TheThe ventilation will thenthen vary with thethe weather. During thethe summersununer oror inin a hot climate, thethe effects of thethe wind will be decisive. When constructingconstructing new buildingsbuildings considerationconsideration shouldshould be given to the direction of winds when deciding which quarters of the building shouldshould bebe exposedexposed toto suchsuch winds.winds. Different designs are used in order to make use of the natural draught often with some sort of channels in the ceiling.ceiling.

Ventilationventilation cancan alsoalso bebe attainedattained byby using mechanicalmechanical fansfans forfor suckingsucking in or blowing out thethe air.air. ItIt isis thenthen possiblepossible toto havehave locallocal extraction.extraction. The contaminants are caught by the air moving into the extraction system the moment they escape fromfrom thethe process.process. This is often a necessity in industries using toxic substances. An extraction system must be inspected frequently (weekly or more often) and maintained by somebody who fully understands how itit works.works. It is not unusualunusual that systems without regularregular maintenance deteriorate toto thethe pointpoint where theythey onlyonly provideprovide aa falsefalse sensesense of security.security.

Draught

Draught could be defined as a person's sensationsensation of uneven cooling, which is caused by air velocity and/or radiationradiation exchangeexchange with thethe environment. If the ventilation system has been incorrectly adjusted and the air is passing through the roomroom too fast this will cause draught.

Cold windows and walls can also cause draught because thethe cooledcooled air near the cold surfaces will streamstream down andand atat thethe samesame timetime sucksuck upup thethe adjacent air. The air streamsstreams resultingresulting fromfrom thisthis maymay causecause discomfort.discomfort.

Draught is not only unpleasant but may causecause stiffstiff muscles, rheumaticrheumatic pain and similarsimilar problems.problems.

When carrying outout heavyheavy physicalphysical work thethe airair velocityvelocity ensuresensures aa decrease inin thethe heatheat stressstress onon thethe body.body. In Table 6 below the acceptable relation between airair velocityvelocity andand airair temperá-EIEJ-IItemperature is shown.shown. - 9292 -

Table 6.6. The relationrelation between air velocity and air temperature.

Air velocity (m/sec)(mvsec) o0 0.2 0.4 0.6

Air temperaturetemperature (°C)(oe) 20 21 22.5 24-26 (at 50% air humidity)

In reality this relation willwill also dependdepend onon whatwhat kind of workwork is carried out.out.

3.2.6. Lighting

In general, the lighting conditions in mostmost forestry operations are sufficientsufficient.. There are situations, however, when the daylight will not be enough,enough, suchsuch as inin very dense rainforest,rainforest, where almost no daylight reachesreaches the ground.ground.

Poor lighting conditionsconditions areare commoncornmon inin thethe wood-processingwood-processing industry.industry. Both poor lighting and visibility will oftenoften increaseincrease thethe riskrisk ofof accidents andand decreasedecrease productivity.productivity. Other effects of poor lighting or visibility can be fatigue,fatigue , headache, smartingsmarting pain inin thethe eyes,eyes, stress,stress, uncomfortable workpostures and decreaseddecreased capacitycapacity ofof focussing.focussing.

There are three factors decisive inin vision, viz,viz. the light (artificial oror natural),natural), the Obj~object and howhow it reflects light and colours and of course thethe eye and itsits capabilityca ility toto taketake inin light,light, darkness,darkness, movement, colour,colour, etc.etc. These threethree factorsfactors interactinteract inin aa system.system.

The eye

The eye is often comparedcompared withwith aa camera.camera. When thethe amountamount ofof lightlight varies the eye will adjust. TheThe pupilpupil will closeclose downdown when therethere isis moremore light and open up when itit isis darker toto allowallow more ofof thethe availableavailable lightlight into the eye.eye. The pupil can be comparedcompared toto thethe diaphragmdiaphragm ofof aa camera.camera. This ability of thethe eye toto adjustadjust isis calledcalled adaptation.adaptation. TheThe abilityability toto seesee in darkness declines with increasing age due to the fact that maximal opening ofof thethe pupilpupil willwill decrease.decrease.

The eye has a very good ability toto focusfocus on objectsobjects at differentdifferent distances. This ability is called accommodation and also declines with fage. The impaired accommodation and adaptation of older people makes itit particularly importantimportant toto improveimprove lightinglighting conditionsconditions soso asas toto fitfit eacheach individual's requirements.requirements. Even when young the eye will get tired ifif it is forced to change its focus fast and often to objects at different distancesdistances.. - 93 -

Dazzle When thethe eyeeye hashas toto looklook directlydirectly intointo aa lightlight which isis brighterbrighter thanthan what thethe eyeeye isis adjustedadjusted for,for, itit isis dazzled.dazzled. Dazzling cancan alsoalso bebe causedcaused by indirect light, e.g.e . g. whenwhen thethe lightlight isis reflectedreflected fromfrom aa shinyshiny surface,surface, such as glass or a very brightbright surface.surface. The phenomenon cancan also occur when the difference (contrast)(contrast) betweenbetween brightnessbri ghtness andand darknessdarkness isis tootoo great.great.

Dazzling makes itit difficultdifficult toto seesee andand irritatesirritates thethe eye.eye . Dazzling is veryvery common and at thethe samesame timetime itit isis oftenoften difficultdifficult toto putput itit right.right. It is therefore one of thethe most difficult problemsproblems relatedrelated toto lighting.lighting.

Some measuresmeasures which can be taken to aavoidvoid dazzle are: provide lamp shades onon lampslamps directlydirectly ini n the field of vision;vision; ceilings and surfaces around windows withwith brightbright colours;colours; avoidavoid shinyshiny surfaces.surfaces.

LightingLi ghting requirements

There are a number of factorsfactors to consider when planning lightinglighting in a workplace.workplace. The requirements for lighting will depend on, e.g.e.g. the nature of the work (less(less light isis requiredrequired in a sawmill than if thethe tasktask is to carry out a surgical operation); the contrast betweenbetween the object and the surroundings, the colours of the ceiling, walls and machines, thethe distance from the object,object, thethe worker's eyesight,eyesight, etc.etc. It is wellwell knownknown that lighting conditions havehave aa bigbig impactimpact onon production.production.

Usually it will be necessary to have both general lightinglighting - illuminating thethe whole premisespremises fromfrom lampslamps inin thethe ceilingceiling oror onon thethe walls,walls, and local lighting -- directed onon thethe machine oror objectobject thethe worker isis working with.with. Good general lightinglighting cancan preventprevent tootoo muchmuch contrast.contrast.

, , , , , , , / , , , , , , , , / , , , / , , ,N , / , / ' , )' / , /' , , , " , , , / " , , , , , , / / / ,/ , / / , / , ,

Figure 28.28 . General lighting and local lightinglighting of work area. - 94 -

TypeSTypes of light sources

As already mentioned, natural lighting (daylight)(daylight) is the most efficient light - but as it will vary with the time of day and the season and weather, most industriesindustries dependdepend onon artificialartificial lighting.lighting. The most common types of electrical lamps are the bulb (glow-lamp)(glow-lamp) withwith low effective power andand shortshort life.life. The bulb is best suitedsuited forfor locallocal lighting. The other type is the flourescent tube withwith aa muchmuch higher efficiency andand alsoalso muchmuch longerlonger life.life. The flourescent tube does not produce soso much heat as thethe bulb, which isis an advantage inin countries with a hot climate.climate.

Maintenance

Even after installing appropriate lighting it will be insufficient after some time ifif thethe dirt on lamps,lamps, fittings,fittings, surfaces of the room,room, reflectors and anti-dazzle devicesdevices isis notnot removed.removed. Particularlyparticularly inin thethe wood processing industries,industries, where a lot of dust isis produced, regularregular and frequent cleaningcleaning willwill bebe veryvery effective.effective. Also thethe instrumentinstrument lifelife of thethe lamps has toto bebe checkedchecked regularly.regularly.

4. OCCUPATIONAL ACCIDENTSACCIDENTS AND DISEASES

Occupational accidents accidents

As statedstated in Section in Section 1, the goal of1, ergonomics the goal is toof optimize ergonomics the is to optimize the man-task-environmentrnan-task-environrnent system fromsystem the point from of viewthe of point the worker's of viewsafety, of the worker's safety, health, well-being andand efficiency.efficiency. One of the most obvious threats to safety and health isis toto bebe injuredinjured inin anan accident.accident. The prevention ofof accidents isis thereforetherefore aa majormajor tasktask ofof ergonomics.ergonomics.

What is meant by an accident? One can findfind numerousnumerous definitions.definitions. To start with, the words "accident""accident" and "injury""injury" are often used interchangeably, which may causecause somesome confusion.confusion.

An accident is an occurrence which isis usually unexepected, unforeseen, unplanned andand unwanted andand interruptsinterrupts oror disturbsdisturbs thethe progressprogress of any activity andand maymay resultresult in:in:

- injury (to(to people) - damage (to(to property) and/or - delay (time).(time).

An occupationaloccupational accidentaccident couldcould thusthus bebe describeddescribed as:as: "An"An unexpectedunexpected incident or external influence during work leading to injury, damage or delay.delay." " - 95 -

There are many good reasonsreasons for striving to prevent occupational accidents. The basiebasic reasonreason isis "survival""survival" and maintenance of good health,health, but therethere are alsoalso otherother reasonsreasons suchsuch as:as:

- legal responsibilitiesresponsibilities - social obligations - economic advantages - resource conservation.

An accident leadsleads toto differentdifferent kindskinds of losses.losses. These losses are not related just to medical treatmenttreatment andand compensationcompensation ofof costscosts forfor injuries,injuries, but also to losses due toto reducedreduced production caused by delays.delays. Damaged property, repairs,repairs, spare parts or premature maintenance may also be costly. Absenteeism, trainingtraining ofof somebodysomebody toto substitutesubstitute thethe injuredinjured worker,worker, andand lost goodwill areare somesome otherother indirectindirect costs.costs.

Before one isis able toto startstart takingtaking action toto combatcombat accidents,accidents, one should also know the answers toto questions such as WHERE, WHY and HOW the most frequentfrequent andand severesevere accidentsaccidents occur.occur. The following areare helpfulhelpful toolstools to use or analyze in order toto provide answers to these questions:

(1) accident statistics (2) special investigations carried out immediately after an accident (3) near-accidents (or(or near-misses)near-misses) (4) systems-analysis (or(or systems-ergonomics).systems-ergonomics).

A discussion ofof thesethese toolstools willwill follow,follow, butbut firstfirst aa fewfew wordswords aboutabout the problem of occupational diseases.diseases.

QC£UE6!i~n~1_dis~a2e2Occupational diseases It is wellwell known that if one is exposed daily to harmful agents such as dust, noise, vibrations, exhaustexhaust emissions,emissions, chemicals,chemicals, oror toto ergonomically unfavourable working postures,postures, veryvery heavyheavy physicalphysical workload,workload, etc., suchsuch exposure will causecause differentdifferent kindskinds ofof healthhealth problemsproblems -- occupational diseases oror occupation-relatedoccupation-related diseases. Examples of occupational diseases couldcould bebe allergicallergic reactions,reactions, vibration-inducedvibration-induced white fingers, loss of hearing, and disorders in the muscular-skeletal system.system.

mostMost countries,countries, however,however, lacklack reliablereliable -- ifif anyany -- statisticsstatistics onon occupational diseases.diseases. There are many reasonsreasons forfor thisthis lacklack ofof statisticalstatistical information, such as insufficient regular health examinations of the workers and epidemiological surveys.surveys. For this, close liaisonliaison andand contactcontact between safety specialists and medical servicesservices isis requiredrequired -- bothboth partiesparties also need a good knowledge of thethe actualactual working conditionsconditions ofof thethe workers. FUrther,Further, the criteria for the diagnosis vary and so do thethe legallegal statusstatus and classification ofof occupationaloccupational diseases.diseases. It maymay often be difficult toto linklink a certain disorder to specific conditionsconditions inin thethe work -- particularlyparticularly asas itit can often take a long timetime forfor thethe disorderdisorder toto developdevelop andand forfor thethe symptomssymptoms to become evident.evident.

In the case of statistics on accidents thisthis kind of problemproblem isis less.less. Accident data areare discusseddiscussed inin moremore detaildetail below.below. - 9696 --

4.1 Accident StatisticsStatistics

Accident statisticsstatistics can,can, ifif accurateaccurate andand carefullycarefully planned, givegive very useful informationinformation aboutabout what preventive ' measures toto take,take, and also how to give priority toto different measures.measures.

The minimum requirementsrequirements for accident statistics should be that they show how many, how oftenoften andand howhow severesevere thethe accidentsaccidents are.are. This information should be expressed in such a way that one can compare the situation in different forest undertakings and in different countries, and also between different periods.periods. To be able to plan preventive measuresmeasures thethe statistics should also allow for classification of the accidents in different ways.

Two types of indicesindices are used to indicate the magnitude of the occupational accidentaccident problem.problem. The two indices are frequencyfrequenty rate and severity rate, and both are usually related to the number 0of man-hours worked.

According toto internationalinternational recommendationsrecommendations thethe frequencyfrequency raterate forfor aa specified period of time should be calculated by dividing the total number of accidents (multiplied(multiplied by 1 million) by thethe totaltotal numbernumber of man-hours worked by all persons exposed toto riskrisk during thethe samesame period.

Total number of accidents x 1I million Frequency rate = Total number of manman-hours hours worked

Fatal accidents should be distinguishable from other accidents, as well asas accidentsaccidents leadingleading toto permanentpermanent totaltotal disability.disability.

It can be misleadingmisleading only to focus preventive efforts on jobs and workplaces with thethe highest frequencyfrequency rate.rate. The accidents might, forfor instance, be mainly minorminor wounds,wounds, etc.etc. Therefore thethe frequencyfrequency raterate index must be complementedcomplemented withwith anan indexindex forfor severity.severity.

This other index, which shows the severity of the injuries,injuries, should according to thethe samesame internationalinternational recommendationsrecommendations bebe calculatedcalculated byby dividing thethe number ofof lostlost working daysdays duedue toto injuriesinjuries (multiplied(multiplied by 1,000) with the total number of man-hours worked by all persons exposed to risk during thethe actual period.period.

Total number of days lost x 1,000 Severity rate = Total number of man-hours worked In case of a fatal accident or an accident leading to permanent total disability, inin somesome industralizedindustralized countriescountries thethe numbernumber ofof daysdays lostlost isis assumed to be 7,500 days. When the injuryinjury leadsleads toto permanent partial disability thethe severityseverity raterate cancan bebe calculatedcalculated accordingaccording toto thethe scalesscales forfor disability usedused inin differentdifferent countries.countries. If permanent partial disability is expressed as a percentage, it follows that each unit of percent will be equivalent to,75to,75 working days.days. The severity raterate , forfor other injuriesinjuries cancan bebe calculatedcalculated onon thethe basis of the number of sick days converted into working days by multiplying by 300/365. - 97 -

If accident statistics are classified in different ways, this will make thethe recordsrecords muchmuch moremore usefuluseful forfor thethe planningplanning ofof safersafer workwork placesplaces andand work methods.methods. The followingfollowing are examples of factors to · consider inin the classification ofof accidents:accidents:

Kind of operation or activity (e.g.(e.g. felling,felling, cross-cutting,cross-cutting, loading,loading, walking inin thethe forest)forest)

ageryagensY which which is is most most closelyclosely associated associated withwith thethe injuryinjury (e.g.(e.g. tool,tool, mach~ne,mac me, equipment)equipment)

hazardous conditions (e.g.(e.g. defects of agencies, lack of safetysafety equipment)

- unsafe acts (e.g.(e.g. negligence of safetysafety regulations)regulations)

type of accident (e.g.(e.g. fall,fall, knock or stumble against an object)object)

- nature of the injuryinjury (e.g.(e.g. laceration,laceration, cuts, fracture)fracture) - part ofof bodybody injuredinjured (e.g.(e.g. hand,hand, fingers,fingers, eyes)eyes)

personal~rsonal characteristicscharacteristics ·ofof thethe victimvictim (e.g.(e.g. age,age, experienceexperience onon thethe job,Job, training, occupation)occupation)

time (e.g.(e.g. during the day in relationrelation toto the work schedule - hours after startstart ofof work or afterafter meal;meal; dayday ofof thethe week; season)season)

- other conditionsconditions contributingcontributing toto thethe accidentaccident (e.g.(e.g. weather,weather, terrain,terrain, wage-system).

A warning: before startingstarting toto collectcollect anyany data forfor veryvery comprehensivecomprehensive statistics one should have a fairlyfairly detailed planplan forfor both thethe analysisanalysis andand presentation as well as the application ofof thethe statistics.statistics. Why do it, how to do it, when or how often toto do it,it, who shouldshould do itit andand forfor whomwhom ???111---

The informationinformation possible toto gathergather isis unlimitedunlimited -- butbut notnot itsits suitability forfor use.use. Particularlyparticularly thethe availabilityavailability of computerscomputers maymay leadlead to a superfluity of tables and cross-tabulations, while thethe hardhard andand time-consuming, but absolutely necessary, work of data analysisanalysis andand thethe actact of taking preventivepreventive measures maymay stillstill remainremain neglected.neglected. When accidentaccident statisticsstatistics areare well-plannedwell-planned theythey cancan bebe anan invaluableinvaluable tool in efforts to create safer working conditions.conditions.

When oneone studiesstudies the accident statistics from industrialized countries one can see that, inin most of thesethese countries, forestforest work, compared to almost all other industries,industries, has higher frequencyfrequency andand severityseverity rates. And therethere isis evidence thatthat even thesethese high rates are up to ten times higher inin somesome tropicaltropical countries.countries. - 98 -

There are severalseveral reasonsreasons forfor this,this, somesome ofof whichwhich areare listedlisted below:below:

- workers inin many tropicaltropical countries are often unskilled and not given appropriate training,training, ifif any;any;

- low awareness of safety risks among staff involved in forestry operations (and(and asas a consequenceconsequence poor and inadequateinadequate supervisionsupervision and control);

- personal protective equipment isis not available or is not used;

- poor maintenance of tools,tools, chainsaws, machines and equipment;

- poor or inappropriate tools,tools, machines, equipment and working methods and techniques;

- no first-aid available at the worksite (neither(neither equipment nor trained personnel);

- long distances and poor transport facilitiesfacilities for medical treatment in case of injury.injury.

These shortcomings, which are more of an organizational and technical character, are very oftenoften combinedcombined with other factorsfactors which will increaseincrease the risks, such as:

- undernourished andand unhealthy workers; - hot and humidhumid climate;climate; - big trees;trees; - dense undergrowth; - steep and roughrough terrain.terrain.

The statistics onon accidentsaccidents will helphelp toto uncoveruncover somesome ofof thesethese factors, but not allall ofof them.them.

4.2 Accident InvestigationInvestigation

The accident statisticsstatistics may not bebe adequateadequate toto uncover thethe truetrue causes of an accident. An accidentaccident isis thethe resultresult ofof somesome error(s)error(s) inin thethe man-task-tool/Machine/equipment-environmentman-task-tool;machine/equipment-environment system.system.

The error(s) cancan eithereither causecause thethe accident directlydirectly oror indirectlyindirectly through a chain ofof events.events. The accident can also be the resultresult of an accumulation of errorserrors inin thethe system.system.

TOTo find the error(s) one has toto analyze all partsparts ofof thethe systemsystem as well as their integration.integration. This means that the.factorsthe. factors involvedinvolved could be e.g. technical, organizational, sociological, psychological and/orand/or physical.

One way of reachingreaching a better understanding ofof thethe actualactual situationssituations behind the statistics isis toto carrycarry outout specialspecial investigationsinvestigations ofof thethe accidents. These shouldshould taketake placeplace asas soonsoon asas possiblepossible afterafter thethe accidentaccident has occurred, when memories areare stillstill freshfresh andand thethe motivationmotivation toto adoptadopt preventive changes (technical,(technical, organizational,organizational, behavioural,behavioural, etc.)etc.) isis probably higher - at allall levelslevels ofof thethe organization.organization. - 9999 -

This investigationinvestigation must notnot bebe mixed up with any investigationinvestigation aiming at finding aa scapegoat.scapegoat. Persons involved in the investigation must have complete confidenceconfidence inin thethe investigator.investigator.

Veryvery often thethe causecause of most accidents isis believed to be "the"the human factor". Human behaviour is, however, determined by ergonomic factors such as work placeplace characteristics,characteristics, jobjob instructionsinstructions andand information,information, situational and organizational factors,factors, as well as individual factors. These factorsfactors oftenoften explainexplain why peoplepeople taketake risksrisks onon theirtheir jobs.jobs.

Careful analyses have often revealedrevealed 10 to 15 contributing factorsfactors behind anan accident.accident. Therefore one shouldshould not look forfor one specific causecause or one main causecause only,only, butbut insteadinstead looklook forfor asas manymany contributingcontributing causescauses as possible. Probablyprobably it will not be possible to prevent all of them, but the prevention ofof somesome ofof themthem may reducereduce thethe probabilityprobability ofof thethe accidentaccident occurring.

4.3 Near-Accidents

A near-accidentnear-accident (or(or aa near-missnear-miss oror aa narrownarrow escape)escape) isis "a"a suddensudden occurrence thatthat might have resultedresulted inin injury".injury". A Canadian study has shown that, on average, forfor each seriousserious injuryinjury therethere were tenten minor injuries,injuries, thirty property damage casescases andand sixsix hundredhundred near-accidentsnear-accidents oror incidentsincidents which, under slightlyslightly different circumstances,circumstances, couldcould have resultedresulted inin injury (see(see referencereference 29).29). A Swedish studystudy showedshowed thatthat therethere isis a highhigh correlation between thethe causes ofof near-accidentsnear-accidents andand thethe causescauses ofof actualactual accidents (see(see referencereference 53).53).

So studying the causes of near-accidents insteadinstead of actual accidents might be a fasterfaster method of obtaining aa largelarge amountamount ofof material -- enoughenough for statistical analysis.analysis. Another benefitbenefit ofof thethe near-accidentnear-accident methodmethod isis that people involvedinvolved inin thethe studystudy will becomebecome more safety-conscious.safety-conscious. When they are requestedrequested toto reportreport on eacheach near-accidentnear-accident theythey havehave experiencedexperienced for a certain limitedlimited period of timetime - includingincluding thethe causescauses - theythey havehave toto start to analyze the working conditionsconditions andand therebythereby becomebecome more awareaware ofof the risks.risks.

4.4 Systems Analysis

The method emphasizes prevention ratherrather thanthan correctioncorrection ofof problems.problems. It is a method to be applied already atat thethe earlyearly engineeringengineering designdesign andand organizational planningplanning stage.stage. All aspects,aspects, includingincluding accidents,accidents, ofof thethe planning, design,deSign, development, fabrication,fabrication, test,test, installation,installation, maintenance, operation, and overall evaluationevaluation ofof thethe man-task-environmentman-task-environment system should be taken into consideration.consideration.

As accidents can be seenseen asas thethe resultresult ofof errorserrors withinwithin thethe man-task-environment system,system, thethe analysisanalysis ofof errorserrors isis oneone moremore methodmethod ofof helping toto preventprevent accidents.accidents. This approach has been called error-ergonomics.

Errors are looked upon asas interactioninteraction phenomenaphenomena -- asas failuresfailures inin transaction between man and other parts ofof thethe system.system. It is therefore most often not possiblepossible toto understandunderstand thethe errors,errors, oror accidents,accidents, byby studyingstudying - 100 -

each component inin thetile systemsystem separately.separately. Withwith thisthis method oneone undesired event is selected. Thereafter, all of thethe possiblepossible happeningshappenings thatthat couldcould contribute to thethe eventevent areare analyzedanalyzed inin detail.detail.

5. MEASURES AT THE NATIONAL ANDAND ENTERPRISE LEVEL

To promote and facilitate daily occupational health and safety at work and the application of thethe ergonomic concept, measures have to be taken by a number ofof concernedconcerned partiesparties andand institutions.institutions. They must be taken both at the enterprise and the national level, as well as the international level.level. Some examples of thisthis network ofof measures,measures, concernedconcerned parties and institutionsinstitutions are: research,research, education and trainingtraining inin ergonomics, laws and regulations,regulations, health and safety inspections,inspections, accident insurance agencies, trade unions or worker's associations, safety committees, safety engineers, medical services,services, manufacturers and testing stations of tools and machines and international agreements and declarations.

Measures at thethe nationalnational and enterprise levellevel will be discusseddiscussed in detail in Sections 5.15.1 and 5.25.2 below, but first a fewfew words about measures at the international level.level.

Different Unitedunited Nations organizations, e.g. thethe InternationalInternational Labour Organization (ILO)(ILO) and thethe worldWorld Health Organization (WHO)(WHO) have drawn up international agreements, declarations andand workingworking environmentenvironment programmes.programmes. Most countries havehave adoptedadopted them.them. Conventions fromfrom ILOILO and other international organizations have been signed by a number of countries - but not all signatories havehave observedobserved them.them.

Other international bodies which also play anan essentialessential rolerole are the FAQ/ECE/ILOFAOjECEjILO Joint Committee on Forest Working Techniques and Training of Forest workers,Workers, the InternationalInternational Union of ForestryForestry Research Organizations (IUFRO), and the InternationalInternational OrganizationOrganization forfor StandardizationStandardization (ISO).(ISO). These organizations' activities, inin addition to national activities, inin terms of legislation, standards, testing, and informationinformation toto thethe " end-users (to increase their demands) will make ergonomics more readily applicable in practice.

Transfer of technologytechnology fromfrom thethe industrializedindustrialized countriescountries toto thethe developing countries isis another aspect of thethe internationalinternational measures toto be considered. A lot has been achieved in the industrializedindustrialized countriescountries regarding ergonomics inin forestry.forestry. These improvements have,have, however,however, hadhad aa tendency to remain inin thethe industrializedindustrialized world. The transfertransfer ofof technologytechnology does not always mean alsoalso thethe transfertransfer ofof ergonomics.ergonomics. ManufacturersManufacturers frequently offer to developing countries machines, toolstools oror equipmentequipment which do not meet existing safetysafety andand comfortcomfort standardsstandards inin theirtheir ownown countries.countries. Either the buyer may not be provided with informationinformation asas toto what thethe standards are and what is lacking on thethe version offered,offered, oror aa machine is stripped of essential safety itemsitems because itit sellssells better.better. Machinery should also have all instructionsinstructions regardingregarding use, safetysafety andand maintenance translated from the manufacturer's language toto thethe locallocal operator'soperator's language. - 101 -

5.1 Measures atat tliethe NationalNational Level

In many cases, the division here into Measures at the National Level and Measures atat thethe EnterpriseEnterprise LevelLevel will notnot bebe aa very exactexact classification but will only give a roughrough structure to the discussion. At the national level the measures to be discussed are those which are planned and controlled byby partiesparties oror institutionsinstitutions outsideoutside thethe enterprise, and which have a generalgeneral functionfunction inin thethe society,society, suchsuch asas lawslaws andand regulations,regulations, institutions for education, training, researchresearch and extension, governmental bodies e.g. Ministry ofof Labour,Labour, Ministry ofof Health,Health, health and safetysafety inspection services,services, tradetrade unionsunions andand safetysafety associations.associations.

Laws and regulationsregulations

Laws and regulationsregulations shouldshould provide a foundationfoundation and framework for preventive measures againstagainst occupationaloccupational accidentsaccidents andand diseases.diseases. ExamplesExamples are mandatory prescriptionsprescriptions concerningconcerning suchsuch mattersmatters asas generalgeneral working conditions; the design, construction, maintenance, inspection, testing and operation of machines andand equipment;equipment; thethe duties ofof employers.employers. Inspection systems will also be necessary forfor thethe enforcement of mandatory lawslaws andand regulations.regulations.

. ManyMany developing countries lack either part or all of the basics for implementing ergonomics by using legislative measures or collective agreements between employersemployers andand employees.employees.

Some countries, on the other hand, have the necessary national laws and regulations,regulations, but forfor various reasonsreasons thesethese are not recognizedrecognized in practice. One reasonreason for this may be that they are a transcription of the legislation fromfrom an industrializedindustrialized countrycountry with entirelyentirely differentdifferent conditionsconditions andand areare thereforetherefore notnot relevantrelevant to the country in question. AnotherAnother reason may be the lack of knowledge among those concerned as to how toto enforce and followfollow the rules and recommendations.recommendations.

Some other countries have takentaken theirtheir laws,laws, agreements and regulations withwith the basic intention and idea that cooperation between involved parties (employers(employers and employees) isis necessary to organize the health and safety work - with thethe employer being thethe one who isis principally responsible.responsible. Some kind of government-organizedgovernment-organized inspectionsinspections forfor thethe enforcementenforcement ofof mandatory regulationsregulations will,will, asas alreadyalready mentioned,mentioned, bebe partpart ofof thethe system.system. Many countriescountries havehave aa specialspecial healthhealth andand safetysafety inspectioninspection service.service.

Safety associations and accident insuranceinsurance institutionsinstitutions

Safety associations areare examplesexamples ofof institutionsinstitutions outsideoutside aa company.company. These could handle ergonomic and safetysafety matters thatthat areare ofof generalgeneral interest to the industry,industry, but which are expensiveexpensive oror difficultdifficult forfor aa smallsmall enterprise to handle as regardsregards standardstandard andand number,number, suchsuch asas trainingtraining -

- 102 - resources, information material,material, etc.etc. The safety associations couldcould bebe financed, for example, from membership fees or through deduction of a percentage fromfrom compulsorycompulsory accidentaccident insurance.insurance.

Accident insuranceinsurance institutionsinstitutions cancan play thethe rolerole of motivator and financial body of safetysafety andand healthhealth measures.measures.

Manufacturers, dealers and testingtesting institutionsinstitutions

Manufacturers, dealers andand testingtesting institutionsinstitutions of forestforest machines, tools and equipment should be mentioned as parties withwith a major impact on ergonomic conditionsconditions inin forestryforestry practice.practice. Their involvement inin ergonomicergonomic activities and projects has given very good resultsresults inin somesome industrializedindustrialized countries. Safety and comfort standards for tractors and chainsaws and the development of personal protective equipment have, for instance,instance, improved considerably.

Education, vocational trainingtraining and extension

Basically, education, trainingtraining and extension are channelschannels forfor sharing knowledge which isis necessary to spread existing ideas,ideas, and also to generate new knowledge throughthrough research.research. The relativelyrelatively rapidrapid returnreturn on investmentinvestment is a good reason forfor giving highhigh prioritypriority toto trainingtraining inin ergonomics.ergonomics.

Generally speaking, everybody undergoing trainingtraining inin forestryforestry schools at various levels or working inin forestry,forestry, or planning or administering other people's work, or inin other ways directly affecting working conditions in the forest, should receivereceive trainingtraining inin ergonomics as appropriate to their particular kindkind ofof work.work.

Initially, the lack of teachers and instructors familiar with ergonomics will be a constraint and the main obstacle toto thethe introductionintroduction of the subject onon aa broadbroad scale.scale.

It is essential to concentrate on the practical aspects of training in ergonomics, and this impliesimplies a high ratioratio of instructorsinstructors toto students. Training of instructors and updating of theirtheir skills are twotwo well-known and serious problems which are still not receivingreceiving adequate attention. If there is a scarcity of adequate training opportunities inin ergonomicsergonomics for trainers, there will be a scarcity of skilledskilled human resourcesresources at thethe level of the enterprise.

In addition to the special training of ergonomics teachers, many other subject-matter teachersteachers and instructorsinstructors need basic trainingtraining or upgrading in ergonomics to enable nergonomization""ergonomization" of allall appropriateappropriate forestry subjects.subjects.

The following broad levelslevels ofof basicbasic educationeducation areare usuallyusually distinguished:

1. Vocational level:level: practicalpractical trainingtraining ofof forestforest workers,workers, machinemachine operators and forestforest farmersfarmers - atat vocationalvocational schoolsschools andand inin special courses forfor foremenforemen andand otherother peoplepeople directlydirectly organizingorganizing and leading others.others.

2. Technical level: trainingtraining ofof rangers,rangers, technicianstechnicians andand supervisorssupervisors - at technical schoolsschools and inin courses.courses. - 103 -

3. University level: professional education and postgraduate studies for peoplepeople to be engaged inin teaching, research,research, administration,administration, design or management work, with responsibilityresponsibility for,for, e.g. developing and organizing practical work in large enterprises and organizations -- atat universitiesuniversities andand colleges.colleges.

A factor toto bebe consideredconsidered inin the training isis thethe influenceinfluence that the students willwill have, in their future occupations, on essential factors in their Ownown ahdand other people's working environment.environment.

The specific objectives, and accordingly also the training programmes and methods, will vary betweenbetween thethe differentdifferent levels.levels. For each course or each training programme within the levels, the objectives must be specified according toto needs andand practicalpractical experience,experience, asas follows:follows:

1. At the vocational levellevel the trainee should acquire the skills and knowledge Whichwhich will prepareprepare himhim forfor aa jobjob fromfrom whichwhich hehe cancan earnearn aa living.living. He must therefore learnlearn to:to:

- perform thethe jobjob inin anan ergonomicallyergonomically adequateadequate way;way; - avoid risks, harmful influences,influences, fatiguefatigue andand errors;errors; - attain reasonable efficiency andand quality.quality.

EquallyEqually important for the trainee is to develop an attitude whichwhich makes him want toto act inin accordanceaccordance with learnedlearned behaviour. The aim is that the trainee's concept of skill includes ergonomic practices as part and parcel of the work, becausebecause "a"a skilledskilled workerworker isis aa safe(r)safe(r) worker".worker". The concern should include not only the worker's own safety and health, but also the safety and health of others, and the development of a safe working environment. The trainee should therefore acquire an understanding and general knowledge of different aspects of thethe working environment, suchsuch as effects and risksrisks ofof differentdifferent physicalphysical factorsfactors atat thethe workplaceworkplace (e.g.(e.g. noise, chemicals, heat), and existingexisting official regulationsregulations relatedrelated toto ergonomics. The worker shouldshould develop the practical skillsskills so as toto be able to assess and improveimprove thethe actual working situationsituation inin order toto avoid safety and health hazards.hazards. The worker shouldshould alsoalso bebe ableable toto givegive first-aid. An idealideal situationsituation isis thatthat workers areare ableable toto getget aa basicbasic education at vocational schoolschool and later on up-dating trainingtraining inin courses and on-the-job throughthrough skilfulskilful instructors.instructors. Therefore, thethe trainingtraining ofof instructors shouldshould bebe partpart ofof vocationalvocational education.education.

2. At thethe technicaltechnical levellevel thethe studentstudent should,should, havinghaving completedcompleted hishis training, be able to assess thethe working conditions of other people and to detect ergonomicergonomic problems.problems. He must know how to-handleto 'handle bothboth physicalphysical andand psycho-social environmental problemsproblems soso asas toto bebe ableable toto contributecontribute toto anan ergonomic design of the workplace, machine organization and environment. In addition to a general knowledge of man and his working environment, the trainee must obtain practicalpractical knowledge.knowledge. HeHe shouldshould learnlearn thethe basicsbasics ofof assessing, controlling and adjusting work environment factors,factors, and gain practical skill inin applying thethe principlesprinciples ofof ergonomicsergonomics asas wellwell asas first-aid. Knowledge of lawslaws andand regulationsregulations relatedrelated toto safetysafety mattersmatters atat the worksite is particularly importantimportant inin thisthis category.category. - 104 -

In manymany developing countries there are notnot sufficient training facilities at thethe vocational level.level. One important task for graduates at the technical level will therefore be to instruct workers in how to perform their jobsjobs (on-the-job(on-the-job training).training). The very important skillskill ofof howhow toto givegive appropriate jobjob instruction, emphasizing safe and efficient working techniques and methods, should be given much more attention in training at the technical level.level. In order to be able to instruct others, thethe teacherteacher must be able toto do thethe jobjob safelysafely andand efficiently. A change of attitude towards manual work among the trainees may be required, so that they willwill be open and preparedprepared toto learnlearn how actuallyactually toto carry out thethe same practical work as thethe workers. First-line or primary supervisors should also provide a good example to the workers, and will have a decisive influence on how safety regulations are observed atat thethe workplace.workplace. It should be emphasized in the training that the function of a technician or supervisor is not to have a narrow approach to production, but to consider ergonomics and safety aspects as essentialessential partsparts ofof thethe job.job. Even in cases where proper andand safesafe working behaviour has been achieved during vocational training, itit may not be sustained during normal production, because safety isis looked upon as a subordinate function at thethe supervisorysupervisory level.level. Whenwhen unsafe practices are accepted by management, the worker tootoo will come toto accept unnecessary risks. For both levels 1. and 2. the content of the training will be determined by its function, which isis toto acquire skills and knowledge that can be practised straightstraight away.away.

3. At the university level,level, thethe futurefuture influenceinfluence thatthat thethe graduates will have on the development and implementationimplementation of ergonomic principles in education, research,research, design and management must be considered. Their positive attitude towards thethe subject,subject, and motivation to promote ergonomics in the forestry sector are very importantimportant goalsgoals inin thethe training.training.

In addition to a general knowledge of the concepts and philosophy of ergonomics, a deeper insightinsight shouldshould be obtained into the interrelationsinterrelations between man, task and environment, applying a systems-analysis approach. Further, scientific developments inin the fieldfield of ergonomics, specialized knowledge and skills concerning different ergonomic factors,factors, methods and techniques for measuring, analyzing, assessing and controlling thesethese factors, national and international legislation and standards,standards, should be essential parts of thethe training.training.

Ergonomics should be taught not only in basic forestry education programmes, but also through extension activities and continuing education programmes, because:

- It willwill take too long for an ergonomic approach to be adopted in forestry practice before the first students who have been given ergonomic training during theirtheir basicbasic education have graduated,graduated, been employed, and have startedstarted toto introduceintroduce whatwhat theythey learned.learned. - Particularly in systemssystems where hierarchy andand seniorityseniority playplay anan important role, itit will taketake considerableconsiderable timetime beforebefore newcomers,newcomers, bringing new skills and ideasideas intointo thethe system,system, build up enoughenough influence to be able to use these skills and introduce the ideasideas. - 105 -

- Extension and ~ontinuingrontinuing education courses can inin such cases pave the way for new ideasideas and be a preventive measure against resistanceresistance caused by the threat toto prestigeprestige oror lacklack ofof knowledgeknowledge inin thethe system.system. It willwill give newcomers and those already workingworking in the organization a common language.language.

- Ergonomic changes may interfereinterfere with production processes and may have some financial implications,implications, and they might, therefore, meet resistance from management. There are educational needsneeds andand aa needneed for attitudinalattitudinal changes among employers andand senior management in organizations, upon whom the responsibility for effective policies and programmes rests.rests. This group must be made aware,aware, onon aa continuingcontinuing basis, of the concept of ergonomics, legislative requirements, and sources of information.information.

- If appropriate teaching methods are used, the efficiency of extension and continuing educationeducation willwill bebe high.high. Because of theirtheir practicalpractical experience in working life, the trainees will be in a good position to derive great benefitbenefit fromfrom suchsuch training.training.

The general aims ofof thethe trainingtraining (all(all categories)categories) are:

the trainee should develop aa positivepositive attitudeattitude towardstowards ergonomics,ergonomics, and an interest inin andand understanding of thethe conceptsconcepts ofof thethe subject;subject;

- the trainee shouldshould be made aware of thethe great ergonomic problemsproblems inin forestry; - the trainee should obtain sufficientsufficient informationinformation and knowledge,knowlelree, and be motivated for furtherfurther studiesstudies so as toto be able toto contributecontri te to the resolution ofof problems.problems.

- the trainee shouldshould achieveachieve thethe necessarynecessary skillsskills forfor his/herhis/her level.level.

The overall objective should,should, however, be inin thethe affective domain. To reachreach that very importantimportant objective,objective, aa changechange inin thethe trainee'strainee's motivation and attitude towardstowards technology,technology, work andand workers will oftenoften be necessary.

Certaincertain topicstopics areare toto bebe consideredconsidered asas basicbasic inin allall ergonomicergonomic courses. Examples of such basic topicstopics are: safetysafety and first-aid,first-aid, physical and psychological workloadworkload ,, energy expenditure, nutrition,nutrition, workplaceworkplace design, work environment hygiene,hygiene, and applicableapplicable legislation.legislation. Certain theoretical topicstopics mustmust alsoalso bebe covered.covered. All suchsuch topicstopics should,should, however,however, be taught from the viewpoint ofof theirtheir relevancerelevance toto practicalpractical situations.situations.

Teaching methods

Design, methods and coursecourse contentcontent will varyvary dependingdepending notnot onlyonly onon the different categories ofof trainee,trainee, but also onon thethe different systemssystems and environments within which theythey will eventuallyeventually operate. Naturally, thethe availability of resourcesresources inin termsterms of personnel, equipmentequipment andand otherother training facilities will have aa major impactimpact onon design,design, contentcontent andand methods. - 106 -

Teaching methods suitable forfor ergonomicsergonomics trainingtraining areare lectures,lectures, demonstrations, laboratory work, excursions, field practice, seminars, group work, brainstorming sessions, self-study programmes, special assignments andand casecase studiesstudies includingincluding practicalpractical problem-solving.problem-solving. These last would be carried out during periods of practical training and be presented andand discussed subsequentlysubsequently inin class.class. It mightmight be possible to arrange such periods in extension activities, but it is usually difficult to include themthem inin thethe basicbasic educationaleducational system.system.

There are, however, other methods by which the trainee can be exposed to situations where theorytheory isis integratedintegrated withwith practice.practice. The use of checklists isis oneone methodmethod which hashas provedproved toto bebe suitablesuitable inin manymany cases.cases. The use ofof checklists,checklists, supplementedsupplemented byby interviewsinterviews with thethe workers andand other involvedinvolved parties,parties, isis anan effectiveeffective way ofof analyzinganalyzing different jobsjobs and workplaces. The exercise will openopen manymany anan ergonomicergonomic eye.eye. These practical parts of thethe trainingtraining are particularlyparticularly essentialessential forfor studentsstudents who havehave not had any actualactual exposureexposure toto andand experienceexperience of forestryforestry work. In general, better resultsresults will be obtained fromfrom thethe trainingtraining ifif thethe studentsstudents are encouraged toto searchsearch forfor thethe knowledgeknowledge insteadinstead ofof beingbeing restrictedrestricted toto passive listening.listening. Whatever thethe methodmethod chosen,chosen, itit isis importantimportant thatthat thethe material used inin thethe trainingtraining correspondscorresponds as much asas possiblepossible toto thethe actualactual conditions under which thethe studentstudent will laterlater applyapply what has been learned.learned.

The scarcity of suitable ergonomics textbooks, teaching notes, manuals, slideslide collectionscollections oror filmsfilms forfor forestryforestry work inin general,general, and forfor developing countriescountries inin particular, isis aa seriousserious obstacleobstacle toto introducingintroducing ergonomics intointo forestryforestry training.training. There are a number of textbooks available on generalgeneral ergonomics, which mainly discuss industrialindustrial problems.problems. Material focusingfocusing on forestryforestry ergonomics isis usually prepared forfor industrialized countries having other socio-economicsocia-economic and cultural backgrounds. Furthermore, for the lower educational levels, the material should be inin thethe locallocal language.language.

In addition to textbooks on ergonomics, other materialmaterial can be utilized inin training,training, suchsuch asas excerpts fromfrom labourlabour legislation,legislation, nationalnational and international standards,standards, thresholdthreshold limitlimit values, handbooks andand manuals on tools and machines, checklists, models ofof designsdesigns andand bodybody parts,parts, instruments for ergonomic measurement, tools and equipment for practising work methods andand techniques.techniques.

It has already been stressed that,that, initially, thethe scarcityscarcity of trained teachers and instructorsinstructors will most probablyprobably bebe oneone ofof thethe main obstacles.obstacles. A way to overcome suchsuch an obstacleobstacle isis toto engageengage teachersteachers fromfrom organizationsorganizations outside the forestry educational system,system, butbut with aa knowledgeknowledge ofof specialspecial aspects of ergonomics, which are applicableapplicable toto forestry.forestry. Examples of such external contributorscontributors are:are:

- physicians (preventive(preventive medicine, physical workload, physical stressstress diseases, rehabilitation, audiometry, etc.);

- nutritionists (nutrition,(nutrition, energy expenditure, etc.);

- first-aid instructors fromfrom thethe national Red Cross, Red Crescent or similar organization; - 107 --

- physiotherapists (work(work postures,postures, etc.);etc.);

- lawyers (laSour(labour and industrial legislation, social security systems, etc.);etc.);

- representatives fromfrom forestryforestry enterprisesenterprises representingrepresenting management,management, supervisors, trade unions or workers'workers° associations, safety and medical departments who cancan givegive informationinformation fromfrom theirtheir practicalpractical experience;

- representatives of relevant government authorities (Ministry(Ministry of Labour, Ministry of Health, safety inspection board, etc.); and

- representatives of designers and manufacturers of tools, machines and equipment usedused inin forestry.forestry.

When engagingengaging externalexternal teachersteachers whowho maymay bebe expertsexperts inin aa ratherrather narrownarrow field, the course leader must emphasize the necessity for them to deal only with thethe aspects which areare relevantrelevant toto thethe trainees.trainees. For resourceresource persons without any experience ofof forestryforestry work, aa thoroughthorough briefingbriefing onon working conditions inin forestryforestry isis vital.vital.

An additional measuremeasure toto helphelp reducereduce thethe problemproblem ofof teacherteacher shortageshortage is to form teaching teams.teams. One trained teacher can be assisted and supported by persons notnot havinghaving aa formalformal teachingteaching background.background. Such a team will prove useful, forfor example,example, duringduring thethe practicalpractical sessionssessions ofof anan ergonomics course.course. Skilled workers or supervisorssupervisors who havehave hadhad somesome further training cancan assistassist thethe teacherteacher byby givinggiving demonstrations,demonstrations, instruction and supervision to the students when practising appropriate working techniquestechniques and methods.

PrivatePrivate enterprises,enterprises, machine and tool manufacturers, etc. may sometimes be involvedinvolved inin trainingtraining inin whichwhich ergonomicergonomic aspectsaspects areare covered.covered. They may provide short training courses forfor certain groups of employees and operators of particular machinesmachines andand tools.tools. TheirTheir objectivesobjectives may,may, however,however, be too narrow to provide satisfactory skills and knowledge inin ergonomics. withWith the assistance of forestryforestry schools,schools, trainingtraining maymay bebe carriedcarried outout inin purpose-designed courses at private or State forest enterprises.

In otherother words,words, ergonomics as a teaching subject gains considerably from collaboration with forestry practice and with research.research. In industrialized countries, findings from ergonomic researchresearch and practical studies are used as very important teaching aids. InIn most developing countries, there is a marked absence of resultsresults from such researchresearch and studies.

Research

In manymany industrialized countries a considerable amount of ergonomic researchresearch hashas beenbeen carriedcarried out in various forestry activities for a long time. New legislation andand strongerstronger demandsdemands fromfrom employersemployers asas wellwell asas workers have further increasedincreased thethe amountamount andand qualityquality ofof ergonomicergonomic researchresearch and the application of itsits results.results. Examples of ergonomic problemsproblems wherewhere researchresearch effortsefforts havehave beenbeen particularly significant are: causes of occupational accidents and their prevention in terms of technicaltechnical measures - 108 -

(tool andand machinemachine design and function, personal protectiveprotective equipment,equipment, etc.), organizational and administrative measures (payment(payment systems, jobjob rotation, etc.) and behavioural measuresmeasures (training,(training, information,information, motivation, etc.) chainsaw-related problems (noise,(noise, vibration, exhaust emission, etc.), epidemiological studies on specific occupational health problems, and rehabilitationrehabilitation and prevention of occupational diseases.

Examples of researchresearch carriedcarried outout inin variousvarious disciplinesdisciplines are:are:

- Technical researchresearch includingincluding investigationsinvestigations intointo the properties and characteristics of harmful materials, machine guards, design of machines, etc.etc.

- Medicalmedical researchresearch including,including, inin particular, investigationsinvestigations of thethe physiologicalphYSiological and pathological effects of environmental and technological factors and physical circumstances conducive to accidents.accidents.

Psychological research,research, i.e.i.e. investigationsinvestigations of psychological patterns conducive toto accidents,accidents, motivationalmotivational aspects,aspects, stressstress reactions,reactions, etc.etc.

- Statistical researchresearch concerningconcerning occupationaloccupational accidents.accidents.

Such researchresearch has usually been carried out inin very close collaboration with forestry practice and education. State forest services, large and small-scale enterprises, physicians, employees' associations, trade unions, safety associations, government authorities, manufacturers, etc., have frequentlyfrequently been involvedinvolved inin thethe entireentire researchresearch process, fromfrom the planning to the dissemination and application of the results. Teachers and students have often takentaken an activeactive partpart inin thethe research.research. International collaboration through bodies mentioned earlier (ISO,(ISO, IUFRO, FAOjECE/IW)FAO/ECE/ILO) has been extensive.extensive.

Many of the researchresearch findingsfindings from industrializedindustrialized countries are of interest to developing countries; but due to differences between countries in the physical environment, technology, socio-culturalsocia-cultural conditions, education, nutrition, endemicendemic disease, etc.,etc., somesome ofof thethe experienceexperience gainedgained in industrialized countries isis notnot generallygenerally applicable.applicable. The very specialspecial ergonomics problems arising fromfrom working conditionsconditions inin tropicaltropical countriescountries are, to a great extent, unknown. Veryvery littlelittle researchresearch hashas soso farfar beenbeen carried out inin thethe developingdeveloping countries.countries.

There is an enormous and immediateimmediate need forfor more informationinformation about the ergonomic situation inin thethe deve/opingdeveloping countries.countries. Data gathering andand research projects must, however, be so designed as to conform with the countries' carefully analyzed needs andand resources,resources, inin termsterms ofof objectivesobjectives and researchresearch methods used.used.

A major obstacle, besidesbesides limitedlimited financialfinancial resources,resources, isis thethe lacklack ofof experienced and qualified researchresearch workers toto carrycarry outout thethe studies.studies.

To make ergonomics researchresearch possible inin thethe near future by professionals at national level, more emphasis must bebe givengiven toto thethe subjectsubject at university level.level. - 109109 -

Ergonomics trainingtraining ofof undergraduates shouldshould be designed, bearing in mind thatthat itit isis fromfrom thisthis groupgroup ofof traineestrainees thatthat thethe futurefuture expertsexperts will be recruited. There must be considerable flexibilityflexibility in the educational system, allowing the studentsstudents toto specializespecialize in different sub-topics, in accordance with their own interests,interests, as well as the special requirementsrequirements of the community. Special assignments, research workwork and developmentdevelopment of postgraduate study programmes should be closely interrelated components of the education - researchresearch system.system. Recent scientific developments inin thethe field of ergonomics; specialized knowledge and skills concerning different ergonomic factors;factors; methodsmethods andand techniquestechniques forfor measuring,measuring, analyzing,analyzing, assessing and controlling these factors;factors; and national and international legislation and standards,standards, shouldshould bebe essentialessential componentscomponents ofof thethe training.training. Furthermore, the students should receivereceive sufficient training in project planning and in the critical analysis and evaluation of researchresearch findings.

Postgraduatepostgraduate students and researchresearch workers should participate inin international ergonomics courses, workshops and seminars for the exchange of experience and ideas. Initially, however, there is an immediate need for more trainingtraining abroad inin master's andand doctor'sdoctor's degree programmes inin countries with advanced ergonomics researchresearch and practice. More exchange of information, as well as of researchresearch workers and students from researchresearch organizations and universities inin industrializedindustrialized and developing countries,countries, is of mutual benefit.benefit.

5.2 Measures at the Enterprise Level

5.2.1. Technical measures

There are a number of alternative or supplementary measures which may be taken when facing an ergonomic problemproblem inin production. FigureFi~re 29 is an illustration of such alternatives, starting from the most effectiveef~ctive measure to prevent accidents and diseases.diseases.

1. Take away the danger from man. One example is to replacereplace the dangerous method, machine, tool, chemical, etc. by one which isis safe(r) for thethe worker toto use.use.

2. Take man away from the danger. One example is to organize the work or design thethe workplace soso thatthat nono workerworker will staystay withinwithin thethe zonezone ofof danger, e.g. being exposed toto thethe riskrisk ofof aa loadload fallingfalling fromfrom aa cranecrane at one's workplace.

3. Enclose or isolate thethe danger.danger. The use of safetysafety guardsguards isis thethe mostmost frequently applied preventive measure. However, it isis often expensive compared to the safety aspects being taken into consideration and built intointo thethe machine when itit isis constructed.constructed. The safety effect may also be reduced,reduced, or even failfail toto appear,appear, ifif itit means thatthat anan additional effort will be expected on thethepart -part ofof thethe worker,worker, oror ifif it causes him some discomfort.

4. Enclose or isolateisolate thethe worker.worker. One example isis toto useuse personalpersonal protective equipment.equipment. This should always be the lastlast solutionsolution to choose, when all other solutions have been investigated and found to be unsuitable. The use of personalpersonal protectiveprotective devices will alwaysalways cause some discomfort toto thethe worker, andand be a hindrancehindrance toto hishis performance. Unfortunately thisthis will inin many cases,cases, particularlyparticularly inin forestry operations, bebe thethe onlyonly alternative.alternative. (Different itemsitems of personal protective equipment will be discussed furtherfurther inin SectionSection 5.2.1.B.) - 110 -

1. Take away the danger fromfrom man

2. Take man away fromfrom thethe dangerdanger

q

3. Enclose or isolateisolate thethe danger

4. Use personal protectiveprotective equipmentequipment

Figure 29.29. Measures toto preventprevent accidentsaccidents andand diseases.diseases. - 111 -

5.2.1.A. Appropriate technology During thethe last 10-15 years expressions such as "basic"basic technology"technology" and "appropriate"appropriate technology"technology" havehave becomebecome commoncommon inin discussions regardingregarding choice of technology for different forestry operations, particularly in developing countries.countries. InIn particular,particular, thethe transfertransfer ofof a too-sophisticatedtoo-sophisticated and capital-intensive technologytechnology fromfrom thethe industrializedindustrialized countriescountries hashas beenbeen criticized.

According toto aa (FAO,(FAC, 1982)1982) document,document, "the"the technologytechnology shouldshould bebe 'appropriate' withwith regard to local conditions andand to the combined effect on: - production, quantity and quality - employment - ergonomics, occupational safetysafety and health - socio-economic conditions - ecology - energy - availability of toolstools and equipment."

The conditions mentioned above differ fromfrom country to country. In many developing countriescountries thethe so-calledso-called basicbasic technologytechnology will bebe thethe appropriate choicechoice forfor many different forestryforestry operations.operations. "Basic technology" standsstands forfor a labour-intensivelabour-intensive technologytechnology using manually-operated equipment.equipment. The utilization of traditional technology is often not efficient inin termsterms of present-daypresent-day standards.standards. The upgrading of traditional technologytechnology has requiredrequired aa furtherfurther development inin lineline with thethe availability of new materials, designsdesigns etc.etc. with thethe aimaim ofof reducingreducing thethe expenditure of physical energy andand improvingimproving productivity.productivity.

It is evident that the choice of technology has direct implicationsimplications for the ergonomic conditions - consequentlyconsequently thethe choicechoice ofof technologytechnology couldcould be used as a tooltool toto improveimprove working andand livingliving conditionsconditions forfor forestryforestry workers.

Training needs areare usually recognizedrecognized asas importantimportant whenwhen introducingintroducing advanced technologies, but overlooked when introducingintroducing newnew formsforms ofof basicbasic technology forfor thethe worker.worker. Also manual tools,tools, suchsuch as thethe bowsaw,bowsaw, will demand much trainingtraining before thethe workers knowknow thethe correctcorrect working techniquetechnique and proper tooltool maintenance.maintenance. No tooltool will be efficient ifif used thethe wrong way. Consequently itit will be very difficultdifficult toto convinceconvince anyany workerworker thatthat the new tool and technique shouldshould be introduced,introduced, ifif not accompaniedaccompanied byby proper training.

5.2.1.B. Personal ProtectiveProtective EquipmentEquipment (PPE)(PEE)

When allall possiblepossible effortsefforts toto eliminateeliminate oror controlcontrol safetysafety andand healthhealth hazards at work have failed,failed, the use ofof PPEPPE must bebe considered.considered. PPEPPE playsplays an important role,role, particularly inin thethe forest.forest.

Analysis ofof accidentaccident recordsrecords fromfrom logging have proved that the introduction of the compulsory use of appropriateappropriate PPE,PPE, andand safetysafety devicesdevices on chainsaws, can resultresult inin a large decrease ofof certaincertain typestypes ofof injuriesinjuries and accidents. - 112 -

There are a number of available varieties of personal protective items such as: helmets, gloves, ear, eye and knee-protectors, boots, safety leggings, etc. SomeSoffit are of poor quality andand design, whilewhile othersothers areare veryvery good and should be of considerableconsiderable help in preventing occupational accidents and diseases ifif usedused byby thethe worker.worker. There are, however,however, obstacles to overcome beforeblore thethe PPEPPE isis actuallyactually wornworn byby thethe intendedintended user.user.

PPE must be available toto thethe worker. It normally represents an expense which the worker inin many countries is unwilling, if not unable to bear.

For certain jobs or worksites, the safety regulations may clearly state the kind ofof PPEPPE toto bebe wornworn byby thethe worker.worker . One of thethe principalprincipal safety tasks of management isis to make this PPE available, so that the regulations can bebe followed.followed. PPE should preferably bebe providedprovided toto allall workers and consideredconsidered asas partpart ofof thethe equipmentequipment necessarynecessary toto bebe ableable toto carry out the work. If notnot provided free of charge, itit shouldshould bebe availableavailable at a reducedreduced price.price. Management should also provide forfor regularregular cleaning for certain items of PPE, particularly when chemicals are handled or when equipment is sharedshared byby severalseveral people.people.

Even when PPE isis provided freefree of charge, itit isis not alwaysal~ys used toto the extent that itit shouldshould be.be. It is decisive thatthat supervisorssupervisors areare wellwell aware of the importance of PPE and are motivated to inform and persuade the workers toto wear it.it. It should be part of thethe supervisor'ssupervisor's responsibilitiesresponsibilities strictly to enforce thethe existingexisting safetysafety regulations.regulations.

Without doubt,doubt, oneone ofof thethe reasonsreasons forfor PPEPPE notnot beingbeing readilyreadily acceptedaccepted by workers isis thethe designdesign ofof thethe items.items. The best protection is provided by protective equipment which thethe worker will wear.wear. Outfits which hinder the work or are inin somesome way uncomfortable,uncomfortable, areare usedused withwith reluctance.reluctance. Particularly in a hot and humid climate workers frequentlyfrequently complaincomplain about, for instance, helmets, earmuffs and gloves which cause discomfort suchsuch as headaches oror eczema.eczema. Existing garments and appliances have to be used until a more appropriate designdesign ofof PPEPPE forfor aa hothot andand humidhumid climateclimate isis developed.

Safety Helmets

The top of thethe human skullskull isis only aa fewfew millimetres thick.thick. If a falling branch fractures the skull, the injuryinjury often leadsleads toto death. The appropriate PPE againstagainst fallingfalling oror flyingflying objectsobjects isis aa hardhard hathat oror helmet.helmet. When working inin thethe forest,forest, aa safetysafety helmethelmet cancan normallynormally bebe consideredconsidered thethe most importantimportant itemitem ofof thethe PPE.PPE.

Requirements of a safety helmet forfor forestforest workers are:are:

Shell_ The helmet must meet recognizedrecognized national oror internationalinternational standardsstandards regarding resistance to impact,impact, penetration and fire.fire.

Usuallyusually hatshats areare mademade fromfrom polyethylene,polyethylene, aa thermoplasticthermoplastic whichwhich isis cheap and gives .good protection against impactimpact andand penetration.penetration. When exposed daily toto heatheat andand sunlightsunlight itit willwill eventuallyeventually deterioratedeteriorate andand - 113 -

Figure 30.30. Personal Protective Equipment (PPE)(PPE) forfor a chainsaw operator.operator. - 114 -

become stiffstiff andand brittle.brittle. Therefore it requires checking forfor crazecraze pattern, dull colourcolour andand chalking.chalking. It should be replaced everyevery 44 years.years. The hat is not suitablesuitable forfor use by firefire fighters, as it softenssoftens at a high temperature.

Helmets made fromfrom fibreglassfibreglass are resistantresistant toto heat and chemicals,chemicals, but are usually ratherrather expensive.expensive. They requirerequire inspectioninspection forfor crackingcracking andand signs of damage to thethe shell,shell, e.g.e.g. deepdeep scratchesscratches oror dents.dents.

Helmets may havehave aa rainrain channelchannel around thethe edge, atat thethe sidessides and rear of the shell near thethe toptop ofof thethe helmet.helmet. There shouldshould bebe specialspecial holes for adequate ventilation incorporatedincorporated in the design by the manufacturer. If thethe holes are made afterwards they will weaken the hat. The helmet should be designed so that itit can be used with ear and eye protection. _Harness _ _ _ The shellshell ofof thethe helmethelmet isis supportedsupported byby aa harness.harness. Between thethe harness and shell therethere must be a clearance of about 2.5 cmem to serve as a buffer in the eventevent ofof impact.impact. It should be possible forfor thethe user toto easily adjust thethe harnessharness toto thethe sizesize ofof head.head. The adjustment shouldshould bebe possible both vertically and laterally. The material in thethe headband should not give rise to skin irritationirritation and shouldshould be proofed against shrinkage and changes inin temperaturetemperature andand humidity.humidity. _Weight _ _ The helmet should have a maximum weight of 300300 gr. when completecomplete with harness, butbut withoutwithout earear andand eyeeye protection.protection. Before getting used toto wearing a helmet, thethe worker oftenoften findsfinds itit tootoo heavyheavy andand givinggiving riserise toto headaches, but even underunder tropicaltropical conditionsconditions thesethese problemsproblems usuallyusually ceasecease after some time, when thethe worker isis used to wearing thethe helmet.

Hearing Protectors

If noisenoise combat has failed, and the noise level exceeds 85 dB(A)dB(A), , the worker should wear individualindividual hearinghearing protectionprotection suchsuch as:as:

Qi2~s~b~e_e~r_p~u3s:Disposable ear plugs: These are thethe least expensive ofof thethe hearing protectors - and usually also the least effective.effective. The material can be of acoustic fibre (a(a very fine glass fibre) or a putty-like substance that isis moulded, when applied to the user's ear.ear. An advantage of disposable plugs isis thatthat thethe problem of dirt causing ear infectioninfection isis negligible.negligible. TheThe useuse ofof plainplain cottoncotton oror eveneven cigarette filter, which isis sometimes seen,seen, isis ineffective.

~e=u2aEI~Re-usable ~a!ear EI~g2plugs There are many differentdifferent typestypes available.available. A veryvery effectiveeffective typetype isis made of expandable foam,foam, whichwhich isis designeddesigned asas aa smallsmall cylinder.cylinder. Before insertion, the cylinder isis pressed togethertogether between thethe fingers.fingers. It must be held inin place inin thethe earear canalcanal forfor aa minuteminute toto allowallow sufficientsufficient expansion. The disadvantage with all reusablereusable ear plugs isis thethe riskrisk ofof earear infection, if not keptkept cleanclean andand hygienic.hygienic. Particularlyparticularly when working in forestry or forest industries this may cause problems. - 115 -

Ear nruffsmuffs

In general, earcar muffsnruffs areare moremore effectiveeffective thanthan earear plugs.plugs. Unfortunately, theythey areare alsoalso moremore expensiveexpensive andand may bebe uncomfortable toto thethe user, particularly inin aa hothot andand humidhumid climate.climate.

Ear nruffsmuffs are eithereither mounted on a band forfor use over or behind thethe head, or mounted directdirect onon thethe safetysafety helmet. When attachedattached toto thethe helmet,helmet, this should be done in such a way that they can be easily retracted. The combined weight of ear pieces and headband, or helmet attachment, should not exceed 200200 g.g.

The seal ringsrings on thethe ear pieces should be made from soft and elastic material, and notnot givegive riserise toto skinskin irritation.irritation. SealSeal ringsrings and sound-absorbing pads should be available as service parts and be easy to replace. All plasticplastic materials,materials, includingincluding thethe ringsrings andand pads,pads, willwill deteriorate when used daily.daily. TheyThey mustnrust thereforetherefore bebe cleanedcleaned and replacedreplaced regularly. To avoid unnecessary distortion of the seals, ear pieces should not be in contactcontact with thethe helmethelmet when inin aa raisedraised position.position. In addition, the.the design and attachment of ear pieces should be such as to avoid branches or other obstructionsobstructions gettinggetting caughtcaught inin them.them.

Eye protectors

When working with chainsaws,chainsaws, oror when pruningpruning treestrees aboveabove eyeeye level,level, or when working near machines, chipschips ofof wood andand sawdustsawdust may fly into the eyes ifif adequateadequate eyeeye protectorsprotectors areare notnot beingbeing used.used. Mostly this does not leadlead toto severesevere injuriesinjuries but causescauses irritationirritation of thethe eyeseyes and disturbs thethe progressprogress ofof work.work. There is, however, always the obvious risk of injuries, even very severesevere ones suchsuch as thethe lossloss ofof sight.sight.

This can be avoidedavoided ifif aa faceface shieldshield oror visorvisor isis usedused which isis preferable to goggles or spectacles,spectacles, as itit will protectprotect notnot only thethe eyeseyes but also part ofof thethe face.face. The face shield can be made of steel mesh or plastic. Inconveniences when wearing a faceface shield are relatedrelated toto glare inin sunshine and decreased visibility inin rainyrainy and darkdark conditions.conditions.

The faceface shieldshield shouldshould bebe mountedmounted onon thethe safetysafety helmethelmet inin suchsuch aa way that it can be easily moved toto and fromfrom thethe "in-use""in-use" position.position. The totaltotal weight ofof safetysafety helmethelmet earear andand eyeeye protectorsprotectors shouldshould notnot exceedexceed 600600 g.g.

Other jobsjobs where eyeeye protectionprotection isis necessarynecessary areare welding,welding, andand sharpening toolstools onon grindinggrinding stones.stones. These and other jobsjobs will requirerequire different typestypes . ofof eveeye protection.protection.

Leg protectors

In forestry work, particularlyparticularly whenwhen axesaxes oror chainsawschainsaws areare beingbeing used,used, many accidents occuroccur involvinginvolving thethe legs.legs.

Good leg protectors, which will preventprevent injuriesinjuries fromfrom accidentalaccidental contact between the leg and thethe chainsaw chain,chain, shouldshould havehave as longlong aa cut-through time as possible and also have a cloggingclogging effecteffect on thethe chain.chain. They cancan be made ofof aa numbernumber ofof layerslayers ofof nylonnylon cordcord oror anotheranother fabric.fabric. - 116 -

Available legleg shieldsshields dodo notnot givegive 100%100% protection, but will partly protect the user and reducereduce thethe riskrisk ofof severesevere injuries.injuries.

The leg shields should be light in weight and flexible so as not to hinder movement ofof thethe legs.legs. They should be sewn into thethe trouserstrousers oror otherwise securely fastened. If not, they may slide round the leg, leaving part of thethe legleg unprotected.unprotected. Furthermore, they should bebe easyeasy toto wash andand dry, and not shrinkshrink oror changechange shape.shape. They should also have a water-repellent surface.surface.

The compulsory introduction of safety leggings for chainsaw operators in some industrialized countriescountries hashas greatlygreatly reducedreduced legleg injuries.injuries.

Knee pads may be considered when working for long periods in a kneeling position and putting the body weight on the knee on a hard surface, e.g. in handsaw operations.operations.

Safety Boots

Nobody shouldshould work barefoot inin thethe forestforest or wood processingprocessing industry. Any kindkind ofof footwearfootwear isis betterbetter thanthan no shoesshoes atat all.all.

In many countries, however, adequate boots are too expensive for the worker toto buy.buy. Good footwear will prevent certain occupational accidents (e.g.slips and falls, cuts, snake bites and penetration of protruding objects) and diseases (e.g.(e.g. infectioninfection fromfrom wounds and hookworms), which may cause long absenteeism. TheyThey willwill alsoalso reducereduce problemsproblems withwith leeches.leeches. Considering these factors, as well as thethe improvementimprovement of work efficiency, proper boots, subsidized by thethe employer, should be provided toto workers.

To ensure satisfactory protection against rough surfaces, the penetration of sharp and protruding objects, impact,impact, crushing,crushing, bruises and cuts, there are certain requirementsrequirements thethe idealideal boot shouldshould meet. A non-slip, impermeable and flexible solesole isis needed. The tread pattern should be deep and self-cleaning, soso asas toto givegive aa goodgood grip.grip.

If chainsaws or cutting tools such as are used, the shoe should have a steel toe-cap, and also a specialspecial lininglining to protect thethe frontfront and as much as possible of the sides of thethe foot,foot, fromfrom cuts and puncture. This lining can be made of impermeableimpermeable material such as nylon oror a specialspecial rubber mixture.mixture. Steel caps are also required whenever there is a risk of heavy objects dropping or rollingrolling onto thethe feet,feet, e.g. when loadingloading and handling logs.logs. Furthermore, the materials and design of good boots should allow sufficient ventilation and also be waterproof. The leg of thethe boot should be water-repellent. During the rainyrainy season, rubberrubber or leather coated with rubber, or other impermeableimpermeable syntheticsynthetic material may be used. During dry and hot periods, leatherleather or reinforcedreinforced canvas isis preferable.preferable. The boots should not be too heavy. To give a snug fit,fit, thethe widthwidth ofof thethe leg of the boot shouldshould bebe adjustable.adjustable. The laces or straps should preferably be at thethe back.back.

In chainsaw work the height of the leg of the boot and the length of safety leggings should be such thatthat no partpart ofof thethe legleg isis leftleft unprotected.unprotected.

The boots should preferably provide support of thethe arch so as to prevent back troubles.troubles. - 117117 --

Safety Gloves

Hands and fingersfingers areare thethe mostmost frequentlyfrequently injuredinjured partsparts ofof thethe body.body. There are few jobsjobs inin forestryforestry andand thethe wood processing industryindustry where gloves are notnot needed.needed. However, different jobsjobs need different typestypes ofof gloves tot o protect thethe workerworker fromfrom cutscuts andand scratchesscratches fromfrom woodwood andand wires,wires, splinters, thorns ofof treestrees andand poisonouspoisonous plants,plants, harmfulharmful chemicals,chemicals, dirt,dirt, vibrations, heat,heat, coldcold andand blisters.blisters. Even when workers areare initiallyinitially reluctant to wear gloves, the wearing of gloves should be strongly encouraged so as toto reducereduce considerablyconsiderably occupational accidents and diseases.

For chainsaw operators the gloves should preferably be made of soft leather or reinforcedreinforced canvascanvas withwith seamlessseamless palms.palms. In a cold climate, thethe gloves can be of fullfull mitten-type design, but thenthen thethe back of thethe leftleft hand and fingers shouldshould bebe protected by an internalinternal layerlayer of protective material, e.g.e.g. nylonnylon cordcord oror rubber.rubber. The glove must be flexibleflexible enoughenough toto allow a comfortable gripgrip ofof thethe frontfront handle.handle.

When handling chemicals,chemicals, e.g.e.g. inin nursery oror plantationplantation work oror inin thethe wood-processing industry,industry, glovesgloves mademade ofof rubberrubber oror plasticplastic cesistantresistant toto chemicals shouldshould bebe used.used. When handling wires and cables the gloves should have reinforcedreinforced palms with internalinternal protective layerslayers ofof e.g. nylon cord.cord. The material must bebe flexibleflexible toto ensureensure aa safesafe grip.grip.

Other PPE

In this section, PPE necessary for some forestry jobsjobs has been discussed. In forestry and thethe wood-working industryindustry therethere areare also,also, however, numerous taskstasks where otherother PPE isis required.required. For example: workers onon certain jobs in the woodworking industry and workers handling harmful chemicals should wear protectiveprotective respiratorsrespirators andand aprons;aprons; fire fighters need flame- and heat-resistant PPEPPE suchsuch as helmets, eyeeye protectors andand gloves;gloves; in floating operations and in water storage of logs, life jacketsjackets should be worn.

5.2.2 Behavioural approach

propagandaPropaganda and persuasion Motivationalmotivational campaigns, competitions, posters, etc. are examples of approaches to safetysafety whichwhich areare frequentlyfrequently used.used. As with all propaganda, it is difficult to assess how long thethe effects will last. Usually there will be a decrease in the raterate of accidents, but thethe improvement may onlyonly bebe temporary.temporary. This does not mean, ofof course,course, that the method isis unimportantunimportant -- quitequite thethe contrary.contrary. A motivational campaign must, however, go beyond simply tellingtelling the worker toto work safely - for example, by ensuring safer work practice and activating the workersworkers so that they make proposals as to how to improveimprove thethe working environment.

When using thethe approach ofof propagandapropaganda andand persuasion,persuasion, itit isis necessarynecessary to do so on a continuouscontinuous basis.basis. Old, faded, dusty posters on safetysafety matters may have thethe oppositeopposite effect onon thethe workers asas theythey realizerealize that safety is not given much attention by the management. - 118 --

Selection and placement ofof workers

No general criteria cancan bebe recommendedrecommended forfor selectionselection ofof applicantsapplicants for employment. However, in order toto reducereduce humanhuman errors,errors, therethere isis aa need forfor specialspecial analysisanalysis ofof thethe particularparticular jobjob inin question.question. Job requirements obtained from such analysis should also be validated as selection criteria.criteria. The "job"job demand profile" shouldshould bebe usedused togethertogether with aa correspondingcorresponding "capacity"capacity profile"profile" ofof thethe worker.worker. TheThe principleprinciple for these profiles is to get a common language for the analysis of the worker's capacity and thethe demands ofof thethe job.job. If properly used this will ensure a better adaptationadaptation betweenbetween thethe workerworker andand thethe job.job.

Ergonomic evaluation of jobsjobs requiresrequires a systematic and thoroughthorough analysis of thethe entire work situation.situation. This may often consist of a complex ofof various elementselements andand aspectsaspects toto examine.examine . There areare several examples of how to carry out such an analysis in a systematic way. AA simple diagramdiagram of the workpworkplacel ace and the operatoroperator can serve asas a starting point for a systematicsystematic dissection of relevantrelevant ergonomic factors of thethe job.job. Another alternativealternative isis thethe use of a checklistchecklist (see Section 7).7).

Training

An attitudeattitude towardstowards safetysafety shouldshould bebe builtbuilt intointo thethe worker's mindmind during thethe basic training.training. The aim should be to traintrain thethe worker soso that his concept of the skill includesincludes safe practices as part and parcel ofof hishis work.work.

In addition, workers shouldshould receivereceive refresherrefresher trainingtraining on safetysafety aspects and proper working techniques.techniques. The trainingtraining shouldshould be given at certain intervals, so thatthat thethe workers do not revertrevert toto unsafe working habits.habits. Updating trainingtraining isis also requiredrequired when introducingintroducing new work methods oror equipment.equipment. Well-trained instructorsinstructors are very valuable forfor on-the-jobon-the-job training.training.

Introduction to safety is.neededis .needed not only for new job applicants but also every timetime therethere isis aa transfertransfer betweenbetween jobs.jobs. This can be done through experienced workers or trainedtrained instructorsinstructors assisting and supervising the newcomer. Newcomers should not be paid on piece raterate until skilled enoughenough toto workwork safely.safely.

Many studies have shown thatthat the most common factorfactor contributingcontributing toto accidents is that the victim isis newly appointed and/or unused toto thethe job. The initiation into the new job should be well-planned and include a follow-up after aa certaincertain periodperiod ofof time.time.

It should involve, if available, the occupational health and safety organization, medical service, tradetrade union or workers' association. Information should be given in a clear way about the workers' rights and duties.

The worker should also be given somesome basic trainingtraining inin first-aidfirst-aid during the introductionintroduction period.period. - 119 -

5.2.3 Organizational measures

Organizational measuresmeasures concern,concern, forfor example,example, productionproduction planning,planning, remuneration system, supervision,supervision, inspection and enforcement of mandatory regulations.

Prevention of accident risksrisks throughthrough organizational measures isis not effective ifif notnot wellwell planned.planned. In Sweden, for instance, thethe introductionintroduction of new safetysafety regulationsregulations onon felling,felling, prohibitingprohibiting thethe workers fromfrom using some very dangerous methods (e.g(e.g methods of taking down hung-up trees), did not significantlysignificantly increaseincrease thethe useuse ofof lessless hazardous methods. A studystudy showed that the main reasonreason for this was that the forbidden methods were considered to be faster and demanded less physical effort. Saving time was equated with better earnings,earnings, becausebecause atat thatthat timetime thethe piecepiece raterate systemsystem was applied. The accident raterate decreased, however, when a new wage system was introducedintroduced based onon timetime worked, which encouragedencouraged thethe workers toto use safer working methods andand toto helphelp eacheach otherother inin hazardoushazardous situations,situations, e.g.e.g. when takingtaking down hung-uphung-up trees.trees.

The traditional approach of accident prevention has been focussedfocussed merely on the worker himself, overlookingoverlooking thethe importanceimportance ofof allall thethe otherother contributing factors inin thethe working environment, somesome of which havehave been discussed above.above.

5.2.4 Occupational health and safety organization

Safety measures in any enterprise should, as a principle, be part and parcel of the normal operations andand shouldshould thereforetherefore not bebe handledhandled asas something separate.separate.

The employer hashas thethe mainmain responsibilityresponsibility forfor occupationaloccupational healthhealth andand safety measures. It is the duty of the employer to provide and maintain working conditions which conformconform toto thethe existing legislationlegislation issuedissued by the country's safety and health authorities. Normally thesethese samesame authorities,authorities, or some other government services,services, also controlcontrol lawlaw enforcement, byby conducting inspections.inspections. In many developing countries nono specialspecial legislation for the forestforest and wood-processing industriesindustries exists.exists. Therefore, in these countriescountries itit shouldshould be thethe concernconcern ofof thethe industriesindustries themselves and of thethe employers toto taketake initiativesinitiatives andand leadershipleadership inin safety and health measures.measures. It is important that toptop management showsshows aa sincere interestinterest byby actuallyactually takingtaking visiblevisible measures.measures. Many largelarge enterprises have established theirtheir own regulationsregulations andand services.services. The differences can be great between enterprises with highhigh standardsstandards andand thosethose with inadequateinadequate standards.standards.

In general, all safety and health measures requirerequire cooperation between management andand workers.workers. First, the employer must ensureensure thatthat thethe workers are aware ofof andand knowknow howhow toto applyapply anyany prescribedprescribed safetysafety measures.measures. The workers, on the other hand, are requiredrequired toto cooperatecooperate byby followingfollowing given prescriptions and reportingreporting on unsafe conditions.conditions.

Cooperation will also bebe neededneeded fromfrom otherother involvedinvolved parties,parties, suchsuch as foremen or supervisors, persons involvedinvolved inin design andand organizationorganization ofof work and in the purchase of equipment, and other staff having anan immediateimmediate influence on thethe working conditions.conditions. - 120 -

There are some very special problems when organizing occupational health and safetysafety servicesservices Withinwithin thethe forestryforestry sector.sector. Due to the fact that the workers are often scattered in remoteremote areas, and that many of the risk factors are relatedrelated to nature itself,itself, e.g. climate, terrain, vegetation, animalsanimals andand insects,insects, itit isis generallygenerally more difficult toto findfind an efficient way to organize the safety and health services in forestry compared toto most otherother industries.industries.

Objectives ofof occupationaloccupational healthhealth andand safetysafety work

The overall objectiveobjective isis toto promotepromote andand maintainmaintain thethe workers'workers' health,health, safety and well-being. To succeed in this itit will bebe necessary:necessary:

to identify the hazardous factors in the working environment whichwhich constitute a threatthreat toto thethe workers' safetysafety andand health;health;

to analyze the hazardous factors, how the workers are affected and how toto preventprevent thethe effects;effects;

to analyze the preventive measures to be taken to ensure that no new risksrisks areare introduced;introduced;

to implementimplement thethe neededneeded improvements;improvements;

. to inform all concerned about risksrisks and prevention; and

to check thereafter that the measures taken have had the intended effect.

All thethe stepssteps mentioned aboveabove aimaim atat thethe preventionprevention ofof anyany healthhealth hazards oror injuries.injuries.

Organization andand functionfunction ofof thethe occupationaloccupational healthhealth andand safetysafety workwork

Although thethe health andand safetysafety aspectsaspects shouldshould bebe part andand parcelparcel of normal production,production, asas mentionedmentioned previously,previously, therethere isis neverthelessnevertheless aa needneed for a separate organization within larger enterprisesenterprises toto handle thesethese matters.

The individualsindividuals engaged inin thethe healthhealth andand safetysafety servicesservices willwill become the experts, but they should at the samesame timetime bebe closelyclosely involvedinvolved inin everyday production. If not, therethere isis a riskrisk of thethe safetysafety and health organization becomingbecoming anan isolatedisolated activityactivity inin thethe totaltotal organization,organization, withwith little power or influence on decisions affecting thethe working conditions.conditions. One very importantimportant functionfunction of thethe personspersons involvedinvolved inin safetysafety andand health mattersmatters isis toto drawdraw attentionattention toto thesethese as'pectsaspects andand to provide information to the management as toto what actions areare needed.

Individual responsibilityreSponsibility

It has already been emphasized that the improvementimprovement of health and safety conditions must be the concernconcern of everyone inin thethe enterprise. In the Introduction, the responsibilitiesresponsibilities of management were discussed. Here, some comments will be provided on thethe rolerole andand responsibilityresponsibility ofof thethe staffstaff being appointed toto carecare forfor certaincertain healthhealth andand safetysafety aspects.aspects. - 121 -

The organization of thethe health and safety services could vary between different undertakings depending on, for example, the total number of workers, thethe numbernumber onon eacheach worksiteworksite andand thethe risksrisks involvedinvolved inin production.production.

In any undertaking which isis largelarge enough,enough, thethe followingfollowing wouldwould bebe applicable:

1) Workersworkers andand theirtheir representativesrepresentatives

The workers must always be aware of what the risks are and how they can reduce the risks. It is the task of management to initiate and maintain this awareness and interest among the workers, regardless of the size of the enterprise. Preferably, a safety delegate should be selected from among the workers and have thethe main duty of working forfor safersafer conditionsconditions at the worksite. The safety delegate should serve as a model, motivate the workers to use safesafe and ergonomic working habits, check that safetysafety regulations are followed and give support and assistance to newcomers regarding health and safetysafety matters.matters. In case of accident, the safety delegate shouldshould bebe involvedinvolved inin thethe investigation.investigation.

In order to be able to carry out these crucial activities at the worksite it will be necessary forfor thethe safetysafety delegates to have support from management. Management should provide them with the information they may need, such as accident statistics, rationalerationale behind new regulations,regulations, etc. They should also participate inin any inspectioninspection of the conditions inin thethe enterprise conducted by outside authorities such as national safetysafety inspection services.services. The duties of thethe workers' safety delegates will require that they are given training on the basics of ergonomics. If the enterprise has work instructors, theythey should work in close cooperation with the safety delegates.

The safety delegates should be compensatedcompensated forfor any incomeincome lossloss theythey may suffersuffer due toto theirtheir dutiesduties inin additionaddition toto theirtheir ordinaryordinary work. The workers' safetysafety delegate shouldshould alsoalso bebe aa membermember ofof thethe safetysafety committee,committee, which will be discussed laterlater onon inin thisthis section.section.

2) Foremen and supervisors

The most common way of looking upon one's duties among foremenforemen and supervisors is to give priority only to matters directly concerned with production. The health and safety aspects are usually considered as something not included in their responsibilities.responsibilities. To change this both dangerous and inefficientinefficient attitudeattitude will bebe decisive, ifif working conditionsconditions at thethe worksite areare everever toto bebe improved.improved. It should be made very clearclear byby management thatthat health and safetysafety mattersmatters areare takentaken seriouslyseriously andand areare given high priority.priority.

The foremen, supervisors or work instructorsinstructors and the workers' safety delegates should cooperatecooperate closelyclosely andand havehave aa consistentconsistent approach.approach. If there are no workwork instructors in the enterprise, a very important task of the foremen or supervisors is to instruct and give newcomers on-the-job training. It willwill therefore be necessary for the foreman or supervisor to be able to carry out the jobjob himself inin aa safesafe andand ergonomic way andand serveserve as a good example.example. - 122 -

3) Safety specialist or safetysafety engineerengineer

In larger undertakings, managementmanagement willwill need the assistanceassistance ofof anan expert to organize andand conductconduct thethe safetysafety work.work. The safety specialist/engineer shouldshould bebe aa membermember ofof thethe safetysafety committeecommittee andand should,should, as a rule, be supported by a safety department with sufficient resources to carry out all thethe duties,duties, suchsuch as:as:

- preparation and evaluation of the safety committee's meetings;

- together with thethe other members of the safety committee make annual safety plans and evaluate the plansplans and activities atat the end ofof thethe year;

- conduct safety inspectionsinspections and follow up suggested corrections or improvements;

- cooperate in thethe planning of training programmes and the realization of the training;training;

- administer the accident statistics and investigateinvestigate accidents;

- organize motivational campaigns, exhibitions, posters, information material, etc.;etc. ;

- cooperate with and collect information fromfrom outside safety associations, accident insurance companies, governmental bodies, (e.g. MinistryMinistry of Labour, Ministry ofof Health),Health), etc.;etc.;

- have aa closeclose collaborationcollaboration with thethe technicaltechnical departments,departments, thethe medical department andand thethe workers' associationassociation oror tradetrade union; and

- organize the purchase, distribution and inspectioninspection of personal protective equipment.equipment.

In order to succeed inin all these and other duties the safety specialist or engineer must, in addition to high ergonomic and technical qualifications, also havehave thethe capabilitycapability toto cooperatecooperate with thethe foremen,foremen, supervisors, workers, etc. and the gift of convincing and motivating others - from management toto thethe workman.workman.

The safety committee

Enterprises employing 50 or more workers shouldshould form a safety committee. In principle, a safety committee should have an equal number of representatives from the employer's and the employees' side. It goes without sayingsaying thatthat thethe workers'workers' safetysafety delegate,delegate, thethe safetysafety engineer,engineer, aa representative from management and the medical doctor and/or nurse from the company health service, ifif any,any, shouldshould bebe membersmembers ofof thethe safetysafety committee.committee. Other members could bebe part-part- oror full-timefull-time safetysafety officersofficers andand representatives of thethe foremen/supervisors.foremen/supervisors. The chairman could bebe someonesomeone from top management toto manifest thethe weight givengiven toto safetysafety matters byby management.

It is important that the committee hold regularregular meetings. The meetings mustmust bebe meaningfulmeaningful andand thereforetherefore theythey requirerequire carefulcareful preparation.preparation. - 123 -

The safetysafety committeecommittee hashas manymany purposes,purposes, suchsuch as:as:

- to streamline the safety and health workwork so that everyone willwill strive for common gcals which areare clearlyclearly statedstated inin aa safetysafety programme;programme;

- to provide a necessary opportunity to exchange experience, ideas and information between different departments andand expertsexperts withinwithin the enterprise. The actual conditions in the enterprise will thereby be better known toto allall members;members;

- to plan jointjoint activitiesactivities toto promotepromote healthhealth andand safety;safety;

- to invite specialists from outside the enterprise as resource persons or consultants who could contribute to the solution of certain health and safety problems; and - to handle special duties, such as safety inspections: to plan, conduct and evaluate safety inspections, and to make suggestions about measures toto correctcorrect unsatisfactoryunsatisfactory conditions.conditions.

Safety inspectionsinspections These inspections can be of different types according to their purpose, e.g.:e.g.:

a) general safetysafety inspections,inspections, onceonce oror twicetwice a year, which aimaim at an overall inspectioninspection ofof thethe generalgeneral standardstandard of thethe working environment; b) detailed safetysafety inspectionsinspections cancan bebe carriedcarried out regularlyregularly but more frequently than the general safety inspection and aim to check the conditions within specific areasareas ofof thethe totaltotal enterprise; and

C)c) special safety inspections which are carried out when there is a specific problem or question toto solve.solve. Special safetysafety inspectionsinspections could, forfor instance,instance, be conductedconducted toto getget a picture of thethe problems related to noise, hand-arm vibration, work-schedules, handling of chemicals, etc.etc.

whateverWhatever typetype itit is,is, thethe inspectioninspection mustmust bebe carriedcarried outout inin aa systematic way, usually withwith thethe helphelp ofof aa checklist.checklist. Careful notes should be made of thethe observationsobservations duringduring thethe inspection,inspection, andand ofof thethe measuresmeasures suggested to correct the conditions. All notes, completed checklists and others should be kept. If a safety engineer isis available this should be his task, and he shouldshould actact asas thethe committee'scommittee's secretary.secretary.

5.2.5 OCcupationalOccupational health services

It is important, particularly inin thethe forestryforestry sector, forfor workers to have access to a companycompany health serviceservice asas theythey work inin areasareas usuallyusually without (or(or with very poor) medical services.services.

In addition to all the common tropicaltropical diseases, of which many are endemic, forestryforestry workers are exposedexposed toto aa numbernumber ofof occupationaloccupational risksrisks which can affect their health andand safety.safety. - 124 -

The functions of occupational health services

The taskstasks of thethe companycompany health service are several and could be classified according toto whetherwhether thethe measuresmeasures willwill havehave aa preventive,preventive, curative or rehabilitatingrehabilitating effect.effect.

Whatever thethe activityactivity is,is, it isis necessary to have close collaboration with thethe safetysafety officersofficers andand otherother membersmembers ofof thethe safetysafety committee.committee.

In June 1985, the previous ILO Recommendation concerning OccupationalOccupational Health Services was revised.revised. In the new Recommendation 171 it is stated that: The rolerole of occupational health services should be essentially preventive. Occupational health services should establish a programme of activity adapted to the undertaking or undertakings they serve, taking into account in particular the occupational hazards in the working environment as wellwell as the problems specific to the branches of economic activity concerned.

The following broadbroad functionsfunctions maymay bebe mentioned:mentioned:

1. Surveillance of thethe workinsworking environment, which also implies that the occupational heaTtEheaItn servIces-snoula:- -

a) carry out monitoring ofof workers'workers' exposureexposure toto specialspecial healthhealth hazards,hazards, when necessary;necessary;

b) supervise sanitary installations and other facilities for the workers, suchsuch asas drinkingdrinking water,water, canteenscanteens andand livingliving accommodation,accommodation, when provided byby thethe employer;employer;

C)c) advise on thethe possiblepossible impactimpact onon thethe workers' healthhealth of thethe use of technologies;

d) participate inin andand adviseadvise on thethe selectionselection ofof thethe equipmentequipment necessary for the personal protection of the workers against occupational hazards;

e) collaborate inin jobjob analysisanalysis and inin thethe studystudy ofof organizationorganization and methods of work with aa view toto securingsecuring aa betterbetter adaptationadaptation ofof work to the workers;

f) participate inin thethe analysisanalysis of occupationaloccupational accidentsaccidents andand occupational diseases andand inin accident preventionprevention programmes.programmes.

2. Surveillance ofof the!h~ workers'~oEk~r~'_h~a.!t!!; health; which may include:include:

a) health assessment of workers before theirtheir assignment toto specificspecific tasks which maymay involveinvolve aa dangerdanger toto theirtheir healthhealth oror thatthat ofof others.others. The physical and mental capacitycapacity ofof thethe worker shouldshould bebe comparedcompared with thethe jobjob requirementsrequirements soso asas toto facilitatefacilitate aa successfulsuccessful placementplacement of the worker. - 125 -

b) health assessment at periodic intervalsintervals during employment which involves exposure to a particular hazard to health, for example regarding loss of hearing, lung symptoms or other diseases related to the jobjob inin question.question. Very young and old workers should be examined more frequently;frequently;

c) health assessment on resumptionresumption of work after a prolonged absence for health reasonsreasons for the purpose of: determining its possible occupational causes; recommendingrecommending appropriate action to protect the workers; determiningdetermining thethe worker'sworker'S suitabilitysuitability forfor thethe job;job; needsneeds forfor reassignment and rehabilitation;rehabilitation; andand

d) health assessmentassessment onon andand afterafter thethe terminationtermination ofof assignmentsaSSignments involving hazards which might cause or contribute to future health impairment.

3. Information, education, training, advice

These activitiesactivities areare ofof aa preventivepreventive character.character. Some examples are:are:

- health andand hygienehygiene education ofof thethe workers inin an endeavourendeavour toto changechange behaviour and attitudesattitudes relatedrelated toto health, hygienehygiene and feedingfeeding habits. This sounds like an easy programme but may includeinclude the following steps:steps:

a) social diagnosis, e.g. living conditions including accommodation, sanitation, water reservoirs;reservoirs;

b) epidemiological diagnosis toto findfind thethe health problems which may be linked toto thethe socialsocial andand workingworking conditions;conditions;

c)C) behavioural diagnosis diagnosis - which habits - which are epidemiologically habits are linked epidemiologically to linked to health problems? problems? and and

d) educational educational diagnosis diagnosis - to assess what - tofactors assess will facilitate what orfactors will facilitate or complicate health education,education, e.g.e.g. attitudes,attitudes, knowledge.knowledge.

- training and retrainingretraining inin first-aid,first-aid, and continuing training ofof personnel who contribute toto occupational safetysafety and health.

It is important that the staff at thethe companycompany health service,service, e.g.e.g. the physician, nurse andand physiotherapist, areare familiarfamiliar withwith thethe workingworking conditions atat thethe workplace.workplace. Regular visits to the field are decisive ifif they are to revealreveal thethe causescauses ofof injuriesinjuries andand work-related diseases.diseases. To be able to participate inin thethe work of improvingimproving thethe conditionsconditions andand suggestsuggest solutions to thethe safetysafety committee, thethe actualactual conditionsconditions mustmust bebe knownknown inin detail by thethe medicalmedical staff.staff.

4. !i!s!-~i9,_e~!g~n£Y_t!e~~eEt_~d_h~a~~First-aid, emergency treatment and health Er2g!~sprogrammes ILO Recommendation 171 says further that:that: takingtaking intointo account national law and practice, occupational healthhealth servicesservices shouldshould

- provide first-aid and emergency treatmenttreatment inin casescases ofof accidentaccident oror indisposition of workers; - 126 -

- carry out immunisationsimmunisations and collaborate with health authorities in public health programmes; and

- engage in other health activities including both the workers and their families.

5. Other functions

Company health servicesservices maymay also,also, e.g.e.g.

- draw up plans and reportsreports at appropriate intervals concerning their activities andand healthhealth conditionsconditions inin thethe undertaking.undertaking. The employer,employer, the workers' representativesrepresentatives and the safety and health committee should have access toto thesethese plansplans andand reports;reports;

- within the limits of the resources the company health service should contribute toto research,research, byby participatingparticipating inin studiesstudies oror questionaires.questionaires.

The organization of occupational health services

According toto ILOILO RecommendationRecommendation 171,171, occupationaloccupational healthhealth servicesservices should, asas far as possible, be located withinwithin or near the place of employment, or should be organized inin such a way as toto ensure thatthat their functions are carried out at the place of employment.

In accordance with national conditions and practice, occupational health servicesservices maymay bebe organizedorganized by:by: a) the undertakingundertaking or groups of undertakings concerned; b) the public authorities oror officialofficial services;services; c) social security institutions;institutions; d) any other bodies authorized by thethe competentcompetent authority; e) a combination ofof anyany ofof thethe above.above.

Conditions of operation

Occupational healthhealth servicesservices shouldshould preferablypreferably bebe mademade upup ofof multidisciplinary teams,teams, e.g.e.g. technicaltechnical personnelpersonnel with specializedspecialized trainingtraining and experience inin suchsuch fieldsfields asas occupationaloccupational medicine,medicine, occupationaloccupational hygiene, ergonomics, occupationaloccupational healthhealth nursingnursing andand otherother relevantrelevant fields.fields. They should, as farfar asas possible,possible, keepkeep themselvesthemselves upup toto datedate withwith progressprogress in the scientific and technical knowledge necessary toto perform theirtheir duties and should be given thethe opportunityopportunity toto dodo soso without lossloss ofof earning.earning. The occupational health servicesservices should,should, inin addition,addition, havehave thethe necessarynecessary administrative personnel forfor theirtheir operation.operation.

within thethe frameworkframework ofof aa multidisciplinarymultidisciplinary approach,approach, occupationaloccupational health services shouldshould collaboratecollaborate with: a) those services which are concerned with thethe safetysafety ofof workers inin thethe undertaking; b) the various production units, or departments, inin orderorder toto helphelp themthem inin formulating and implementing relevantrelevant preventive programmes;programmes; - 127 - c) the personnel department and other departments concerned; and d) the workers' representatives in the undertaking, workers' safety representatives andand thethe safetysafety andand healthhealth committee,committee, wherewhere theythey exist.exist.

5.2.6 First-aid and emergency treatment

First-aid is the immediate treatment given to someone who is injured or has suddenly become seriouslyseriously ill when there isis no qualified medical assistance available (e.g.(e.g. physician, nurse or ambulance crew). First-aid includes not only physical treatment of the injury or illness but also psychological encouragementencouragement ofof thethe victim.victim. The first-aiderfirst-aider deals withwith thethe whole situationsituation includingincluding bothboth thethe injuryinjury andand thethe victim.victim.

Knowledge and skill of how to give first-aid treatment will increase the chances of survival inin casescases of seriousserious injury,injury, or itit may mean a temporary disabilitydisability only instead of a permanent one, or a speedy recovery instead of lengthy hospitalization. First-aid knowledge will also develop a person's safety awareness and lead to safer working habitshabits andand therebythereby helphelp toto preventprevent accidents.accidents.

The benefits of first-aid are particularly evident in forestry operations which often includeinclude dangerous operations inin remoteremote areas without any medical services andand with very poor transport.transport. InIn suchsuch cases, andand where many workers areare employed,employed, itit isis necessarynecessary toto havehave well-trainedwell-trained first-aiders and comprehensive first-aidfirst-aid equipment.equipment.

At leastleast twotwo persons,persons, e.g.thee.g. the foremanforeman oror supervisorsupervisor andand oneone more person, with thorough knowledgeknowledge and skillskill of first-aidfirst-aid shouldshould be availableavailable at the workplace oror thethe forestryforestry camp.camp. In many situations the chances forfor successful first-aid treatmenttreatment will increaseincrease ifif therethere are twotwo first-aidersfirst-aiders to cooperate, e.g. when artificial respirationrespiration isis needed.needed. These persons should be re-trained periodically and should also know the proper first-aid treatment of acute illnessesillnesses suchsuch as appendicitis, heartheart disorders,disorders, toothache, fever,fever, etc.etc.

At stationary work placesplaces andand inin logginglogging campscamps therethere shouldshould bebe aa first-aid room, and inin thethe fieldfield aa well-equippedwell-equipped first-aidfirst-aid box.box. The contents of the box shouldshould meet thethe needs specificspecific toto thethe workplace. The company physician or nurse shouldshould be consultedconsulted regardingregarding with which itemsitems and in what numbers thethe first-aidfirst-aid box isis toto bebe supplied.supplied. The requirements will differ dependingdepending on:on: typetype ofof workwork carriedcarried out,out, thethe remotenessremoteness ofof thethe workplace, howhow manymany workers thethe boxbox isis intendedintended for,for, oror specialspecial dangersdangers such as poisonous snakes.snakes. All forest workers shouldshould be given basic first-aidfirst-aid trainingtraining andand regular re-training.re-training. Preferably,preferably, each worker shouldshould be equipped with a pocket-size first-aidfirst-aid kit.kit. A minimum requirementrequirement isis oneone first-aidfirst-aid kitkit inin each group of workers working togethertogether oror very nearnear eacheach other.other.

Preferably all motor vehicles should have a first-aidfirst-aid kitkit andand ifif thethe vehicle is used forfor workers' transporttransport thethe first-aidfirst-aid kitkit shouldshould bebe comprehensive. In all of the more well-equipped first-aidfirst-aid kits an illustrated first-aid guide should be included. - 128 -

First-aid training is a most important activity for the company health service. First, the trainees must be motivated toto learn.learn. The usefulness and benefits of first-aidfirst-aid knowledge should be explained, e.g. how to treat minor injuries, how to put to bed or transport more seriously injured persons, and how to judge when an injury mustmust be treated byby aa physician. All first-aidfirst-aid trainingtraining shouldshould be directed towardstowards practical skills. The treatment of such injuries as could be expected at the trainees' workplace shouldshould bebe emphasized.emphasized.

Each trainee should bebe requiredrequired toto demonstratedemonstrate hishis oror herher skills;skills; passive listening or watching will not give the necessary skills. Regular re-training should be organized atat leastleast everyevery secondsecond oror thirdthird year.year. All foremen or supervisors should receivereceive instruction from advanced first-aiders.

No furtherfurther instructionsinstructions onon immediateimmediate first-aidfirst-aid treatmenttreatment will be given in this chapter.chapter. The reader is strongly recommendedrecommended toto acquireacquire knowledge and skills in first-aid treatment and to undergo special first-aid training.training. It would be an underestimation ofof thethe needneed forfor practice and thoroughthorough knowledgeknowledge ifif onlyonly aa fewfew pages ofof summarizedsummarized guidelines and illustrationsillustrations werewere givengiven here.here. The same isis truetrue regardingregarding suggestions for the contents of the first-aid kits and boxes, which should be as custom-madecustom-made asas possible.possible.

5.2.7 Work study

This section is based on twotwo publications, namely "Introduction"Introduction to work study",study", 3rd3rd edition,edition, ILO,lLO, Geneva, 1979 and "Forest work study nomenclature inin Denmark, Finland,Finland, NorwayNOrway andand Sweden", TheThe NordicNordic ForestForest Work StudyStudy Council.Council. BulletinBulletin No.No.1, 1, 1963.1963. The content consists mainly ofof excerpts and paraphrases fromfrom thesethese twotwo publications.publications. The aim of this section is to give the reader a brief introduction to the work study and its application in forestry work and to show the rolerole of work studies as a useful tool inin thethe frameworkframework ofof ergonomics.ergonomics. The interestedinterested readerreader isis recommended to carry out further studies of the topic. Brief answers will be given to the questions: WHAT isis work study?study? andand WHY, WHEN andand HOWHCM cancan itit be used?

Work Studystud isis a genericgeneric termterm forfor thosethose techniques,techniques, particularlyparticularly method studystudy andana workwork measurement,measurement, whichwhich areare usedused inin thethe examinationexamination ofof huMairiEllman Work-inokinall-iIs-ci3nIeXt,-and all-its-contexts,-and which which lead lead systematically systematically toto thethe investigation of all factors which affect the efficiency and economy of the situation being reviewed, in order to effect improvement.1/irnprovement.~1

Work studystudy isis systematicsystematic andand objectiveobjective bothboth inin thethe investigationinvestigation ofof the problem being considered andand inin thethe developmentdevelopment ofof itsits solution.solution. Besides aiming at the most rationalrational method ofof carryingcarrying outout work, work studystudy serves as a base of wage paymentpayment plans.plans. However, to ensure the scientific integrity of workwork study it is of great importance to separate it from discussions onon wage levels.levels. There is a fundamentalfundamental differencedifference betweenbetween workwork study and pricing of work. PricingPricing ofof work will notnot bebe furtherfurther discusseddiscussed here.

1/ The definition given herehere isis thatthat adoptedadopted inin thethe "British"British StandardsStandards InstiInstitution: tution: glossary of terms used inin work study"study" (London(London 1969). - 129129 -

Mostmost of thethe problemsproblems whichwhich are approachedapproached by using work studystudy require a synthesissynthesis of of measuring measuring systems systems andand alsoalso experience experience gained gained from from ergonomic, ergonomic, technical, medical,medical, climatological, sociological and otherother fieldsfields ofof research. So whatwhat thenthen are thethe techniquestechniques - -method!!.lE!!h2'i_s.!;u3Y study and and work_~!k _ measurement - - mentioned above in thethe definitiT:in'fdefinition? Method studystudy Method study study is is thethe systematic recording and criticalcritical examination examination ofof existing and and proposedproposed waysways of doingdoing work,work, asas aa meansmeans ofof developingdeveloping andand applying easier andand moremore effectiveeffective methods methods andand reducingreducing costs. TheThe . objectives areare: - to improveimprove processes andand procedures;procedures; - toto improve improve workplaceworkplace layoutlayout and thethe design ofof plant,plant, machines, machines, tools andand equipment;equipment; - to economizeeconomize onon humanhuman effort effort andand reduce unnecessary fatigue;fatigue; - to improveimprove thethe useuse ofof materials, materials, machines machines and and manpower; manpower; andand - to developdevelop aa betterbetter working working environment. environment. Workwork measurement

As mentionedmentioned in in thethe definition of of work work study,study, method method studystud~ waswas oneone technique used inin workwork study.study. Another technique,technique, also mentionedmentione inin the definition, is is work work measurement. measurement. workWork measurement measurement is isthe the application application ofof techniques designed to establish thethe timetime forfor aa qualifiedqualified workerworker toto carrycarry outout aa specified job atat aa defined level ofof performance. performance. So ifif methodmethod studystudy isis thethe principalprincipal technique technique forfor reducing reducing thethe work work involved, primarily bybY eliminatingeliminating unnecessary unnecessa~ movementmovement on on the the partpart of material oror operativesoperatives ;iliaand oy-sUbstItutIng -§ood-m-éthdasgoOO-metnods for for poorpoor ones, workwork measurement is is concernedconcerned with with investigating, investigating, reducingreducing andand subsequentlysubsequently ---­ ~l!m!n~tingeliminating in~f!e~t.!:v~ineffective time,.!;i!!.lE!' thatthat is, is, time time during during which which no no effectiveeffective work work is-biTeirig'perTOirde-dj1S being perlormed, -TITTht7év-e-r whatever the the cause. cause. Application inin forestry In the industrialindustrial field,field, work work studystudy hashas beenbeen usedused toto aa far greatergreater extent than inin forestry. As toto the pre-requisite ofof thethe jobsjobs under under observation andand also also thethe problemsproblems in in respective respective cases, cases, there there isis aa greatgreat difference betweenbetween industry industry and and forestry. forestry. In important respectsrespects this alsoalso applies toto measuringmeasuring techniques.techniques. Work study study proper proper is is often often applied applied in in industryindustry toto relatively shortshort work operations,operations, often inin more more oror lessless automatized automatized operationsoperations wherewhere thethe working conditions conditions are are stabilizedstabilized andand yetyet moremore easily influencedinfluenced byby management than than in inforestry. forestry. In In forestry,forestry, thethe workingworking conditions varyvary toto a great extentextent both both in in time time and and space space and and the the methods methods are are also also more more dynamic. dynamic. Method study study used used in in forestry forestry has,has, therefore, requiredrequired otherother systems systems forfor - 130 -

work measuring.measuring. These are usually based on planned field experiments and statistical analysis.analysis. For ergonomic purposes, work studiesstudies shouldshould bebe combined with physiologicalphysiological studies.studies.

Examples of studiesstudies inin which work study has been used as a tool to evaluate the appropriateness of different technologies, tools, tool design and tool maintenance areare "Choice"Choice ofof TechnologyTechnology inin Forestry.Forestry. A Philippine Case Study" (ILO,(ILO, 1981)1981) andand "Men"Men andand ToolsTools inin IndianIndian LoggingLogging Operations. A pilot studystudy inin ergonomics"ergonomics" (Hansson(Hansson etet al.,al., 1966).1966).

6. ERGONOMIC PROBLEMS IN DIFFERENT FORESTRY ACTIVITIES

6.1 Working andand LivingLiving ConditionsConditions ofof ForestryForestry Workers inin General

In many countries, forestry work is regarded as a low status occupation. Salaries are lower than those of most other wage earners. Many forestry workers are casual workers without securesecure and permanent employment. Vocational training forfor forestryforestry workers isis rarerare inin developing countries. A number of studies, carried out in different countries around the world, have confirmed thatthat forestryforestry work isis among thethe heaviest inin all industries. The provision of foodfood of sufficientsufficient quantity and quality isis therefore particularly important.important. Due to low salaries andand remote,remote, isolatedisolated and scattered workplaces inin areas with poor infrastructure,infrastructure, many forestryforestry workers havehave difficultydifficulty inin gettinggetting sufficientsufficient food.food. They suffer fromfrom a too-low energy intake and often thethe nutritive value isis farfar fromfrom optimal. To carry out dangerous and heavy physical work while being malnourished will very likelylikely resultresult inin healthhealth problems.problems.

Health, medical and other socialsocial servicesservices inin thethe areasareas where forestryforestry activitiesactiviti~s taketake placeplace areare usuallyusually poorpoor oror non-existent.non-existent. When the circumstances are such as described here, which isis more thethe rulerule thanthan thethe exception, productivityproductivity isis affectedaffected negatively.negatively. As aa resultresult of low productivity thethe salarysalary will bebe lowlow asas well.well. In this wayway the forestry workers areare caughtcaught inin aa viciousvicious circle,circle, asas illustratedillustrated inin FigureFigure 31.31.

The poor working and livingliving conditionsconditions also affectaffect thethe familiesfamilies of the forestry workers.workers. In many places thethe childrenchildren areare depriveddeprived ofof medicalmedical services and even schooling, which gives themthem small opportunity forfor a better lifelife inin thethe future.future. It is not unusual that labour unions oror workers' associations,associations, ifif theythey existexist atat allall amongamong forestforest workers,workers, areare disregarded. Where theythey areare acceptedaccepted therethere maymay stillstill bebe hindranceshindrances inin activities aimingaiming at thethe promotionpromotion ofof thethe workers'workers' workingworking andand livingliving condiconditions. tions. The fact that the conditions forfor forestryforestry workers andand theirtheir familiesfamilies are soso extremely poorpoor inin almostalmost allall countries,countries, andand thatthat thethe improvementsimprovements are soso slow inin thethe developing countries,countries, mustmust notnot bebe aa reasonreason toto acceptaccept this state of affairs; quitequite thethe contrary.contrary. - 131 -

Lowprockec.iivily

Low conic Loco woraw cap.:reify

' k.I , .14010

Poor healik Poor food,foca, houshig,hotl£inq, earucatior,edut:Qfion

Figure 31.31. The vicious circle of lowlow productivityproductivity andand poorpoor health.health.

6.2 NursesyNursery Work

Nursery activities inin generalgeneral cancan bebe classifiedclassified asas physicallyphysically lightlight work and with smallsmall riskrisk ofof seriousserious accidents.accidents. In many countries itit isis common that much of the work isis carried out by women. Nevertheless, therethere are some both heavy and dangerous tasks even inin thethe nursery. Some of them are discussed here.here.

preparationPreparation ofof the nursesynursery

Even if the ordinary work inin a nursery may be characterizedcharacterized asas safesafe and light, this is not true for the preparation of the site forfor thethe nursery. The workers engaged forfor thisthis work might bebe locallylocally hiredhired andand with no experience ofof suchsuch work.work. It willwill often bebe necessarynecessary to remove standing trees and to uproot heavy stumps.stumps. This involves many risks,risks, particularly when using machines such as tractors,tractors, bulldozersbulldozers andand winches, oror whenwhen blasting. Also soilsoil cultivationcultivation and the removal of small trees and undergrowth with manual toolstools may causecause many accidentsaccidents whenwhen thethe workersworkers areare inexperienced. Inexperienced workers may also not be aware of various risks, such as harmful plants,plants, insectsinsects andand snakes.snakes.

Careful planning, instructioninstruction andand closeclose supervisionsupervision willwill bebe important. The use of good footwearfootwear and gloves, keepingkeeping aa safesafe distancedistance between the workers, proper maintenance of toolstools andand thethe provisionprovision ofof shelter against wind, rainrain and sunsun are somesome measures toto improveimprove workingworking conditions. - 132 -

FencingFencing ofof the nurserynursery is anotheranother activityactivity whichwhich cancan bebe bothboth heavyheavy and riskyrisky work dependingdepending onon thethe kindkind ofof fencing:fencing:

- Usingusing barbed wire will require proper gloves, preferably of thick leather, andand goodgood boots.boots. In particular, the stretching of wires shouldshould bebe donedone withwith greatgreat carecare andand aa safe distancedistance mustmust bebe keptkept whenwhen cutting a wire under tension.tension. Wires andand nailsnails shouldshould not bebe leftleft on the ground, otherwise there is a risk of stumbling or stepping on themthem..

- A stone wall isis durabledurable butbut takestakes aa lotlot ofof energyenergy toto build.build. By using levers, wheelbarrowswheelbarrows and sledges, the workwork load can be veryvery much decreased. GlovesGloves and good boots should be used.

-A bamboobamboo fencefence combinedcombined withwith aa hedgehedge with thornsthorns will notnot causecause anyany big risk or heavy physical work ifif thethe workerworker isis properlyproperly equipped.equipped.

Day-to-day nurserynursery activitiesactivities

Among thethe day-to-dayday-to-day activitiesactivities inin aa nursery,nursery, certaincertain jobsjobs areare heavy,heavy, such as moving material over short distances, particularly if not using proper equipmentequipment andand tools.tools.

Plenty of soil and sand isis needed, especially if growing seedlings in potspots.. Digging will be physically lighter when tools designed for the purpose areare used.used. For example, when heaping looseloose forestforest soilsoil inin thethe nursery a plain spade will be the appropriate tool, but when loading hard material, such as stones, a shovel with a roundround mouth - or else with a pointed mouth oror tiptip -- willwill bebe betterbetter thanthan aa squaredsquared one.one. For certain lobs,jobs, a diggingdigging fork can facilitate the work:work: it is easier to drive intointo thethe soilsoil thanthan aa spade.spade . Footwear with good soles isis needed when digging.digging. The soil and sand must be transportedtransported from the source to the place where itit willwill bebe used.used. This isis preferablypreferably donedone usingusing aa wheelbarrow. Design andand materialmaterial maymay varyvary aa lot.lot. IfIf thethe terrainterrain isis soft, a track made of narrow planks on cross stringers will make a path for a single-wheeledsingle-wheeled wheelbarrow.wheelbarrow. Other solutionssolutions mightmight bebe sledges or yokes, ifif nono animalanimal powerpower isis available.available.

Plenty of water isis alsoalso neededneeded inin aa nursery.nursery. In bigger nurseries the watering of seedlingsseedlings cancan bebe done with,with, forfor example,example , aa sprinklersprinkler system, flood irrigationirrigation oror percolation.percolation. In small nurseries itit isis more common toto do itit byby hand.hand. Watering with aa hosehose will requirerequire lessless effort than using aa can.can.

- Whenwhen producing seedlingsseedlings inin potspots inin nurseriesnurseries therethere willwill bebe plentyplenty ofof work moving thethe filledfilled potspots shortshort distances.distances. Again: wheelbarrows or sledges can facilitatefacilitate thethe workwork considerably.considerably.

Besides all work involvinginvolving short-distanceshort-distance transporttransport ofof e.g.e.g. soil,soil, sand, water or seedlings, much ofof thethe timetime inin aa nurserynursery isis spentspent onon weeding, grading,grading, transplantingtransplanting andand pot-filling.pot-filling. None ofof thesethese activitiesactivities is physically heavy but cancan be tiringtiring due toto poor work posturespostures and/orand/or lacklack of shelter against sun,sun, windwind andand rain.rain. The use of a low stool, insteadinstead of squatting, will give some reliefrelief forfor thethe back,back, legslegs andand knees.knees. If kneeling, a small soft rugrug or kneeknee padspads will protectprotect thethe knees.knees. A small,small, light and portable shelter against thethe sunsun couldcould bebe anan alternativealternative oror complement to a broad-brimmed hathat (see(see FigureFigure 32).32). - 133 -

Even in the tropics, greenhouses are used for germination and rootingrooting of seedlings. Temperatures may be very high unless good ventilation is arranged during working hours.hours. Work rotationrotation or long restrest pausespauses outsideoutside the greenhouse may bebe needed.needed.

Figure 32. A low stool, a soft rugrug or kneepads, a shelter against thethe sun, and a wheelbarrow are examples of simple items which cancan facilitate work inin thethe nursery.nursery.

Perhaps the most hazardous factorfactor inin nursery work isis thethe handlinghandling of different chemicals.chemicals. All pesticides areare toxic.toxic. In nurseries pesticides such as fungicides, herbicides and insecticidesinsecticides are used against plant diseases, weeds andand insects.insects.

Often the pesticides are used onlyonly during shortshort periods ofof timetime each year. It cannot be expected that uneducated workers in the nursery should be aware of thethe risksrisks oror rememberremember allall safetysafety rulesrules fromfrom oneone timetime ofof usingusing to another. The supervisors will have the responsibilityresponsibility of ensuring that no workers are exposed toto safetysafety risks.risks. Much has already been said on this topic in the sequence on "Harmful"Harmful substances, e.g. chemicals, solvents,solvents, gases, smokesmoke andand dust"dust" (3.2.4).(3.2.4). In spite of this, a short repetition may be needed. The following is taken from the booklet "Vallage"Village nurseries for forest trees - how to set them up and how to runrun them":

- Lock poison in a box or cupboard away fromfrom any foodfood andand outout ofof thethe reach of children. Keep chemicals inin theirtheir originaloriginal containers.containers. Never put chemicalschemicals inin containerscontainers withoutwithout "labels. labels. Make suresure thatthat thethe poison store has a clear label:label: POISON and also aa signsign which may easily be understood byby illiterateilliterate persons.persons.

- Make suresure thatthat when youyou use,use, storestore oror throwthrow awayaway pesticides,pesticides, youyou areare following the lawslaws ofof thethe country.country. Check the lawlaw aboutabout pesticides.pesticides. - 134 -

- Always readread thethe labellabel ·and followfollow thethe instructionsinstructions on how toto use the poison. Make suresure all thethe workers understandunderstand howhow toto useuse thethe poison.poison. The label tellstells you what isis inin thethe poison, itsits uses, how much toto use (the doses), and how often.often. It also tells you how to use thethe poison as carefully asas possible.possible. It tells you what to do before you use thethe poison. It also tells you about first-aid:first-aid: what toto dodo ifif somethingsomething goes wrong. If the label is not clear, trytry toto getget aa pamphletpamphlet aboutabout the poison. Never buy or use chemicals that come in sacks or bottles without labels.labels.

- whenWhen thethe containercontainer ofof thethe poisonpoison isis empty,empty, makemake holesholes inin it,it, flattenflatten it, and burybury itit deep.deep. Bury itit inin an areaarea away fromfrom the village and fields, and away fromfrom anyany waterwater supply.supply. DoDo not use an empty container forfor anyany otherother purpose.purpose.

- Always use properproper safetysafety equipmentequipment andand wear protectiveprotective clothingclothing when you use chemicals.chemicals.

- Never smoke,smoke, eateat oror drink while you areare usingusing poison.poison. Wash yourself wiwith th soapsoap andand water bothboth beforebefore restrest periodsperiods andand when you havehave finished thethe job.job.

- wash thoroughlythoroughly allall thethe sprayingspraying equipmentequipment andand otherother toolstools with soapsoap and water after you havehave usedused them.them. When you are washing, take the water to a safesafe place soso thatthat you do notnot harmharm thethe water sources.sources.

- Be particularly carefulcareful with concentratedconcentrated poison.poison. When you mix pesticide solutions,solutions, trytry not toto make splashes.splashes. If youyou spill some of the poison, soak itit up with sawdustsawdust oror soil.soil. Then bury thethe sawdustsawdust or soilSOil in a hole and covercover it.it.

If anybody develops symptoms of poisoning, removeremove him/her from the work area and call a doctor immediately.immediately.

6.3 Planting Activities

Tree planting is becoming a more and more importantimportant activity inin forestry in many developing countries.countries. To date, little interest has in general been shownshown when itit comescomes toto improvingimproving workingworking conditions,conditions, methods,methods, techniques, tools and equipment for tree planting. Tree planting is generally manual work carriedcarried out with simplesimple tools,tools, often by women oror unskilledunskilled labour.labour. The incentivesincentives and benefits of improving tree planting operations are not always perceived by decision makers andand management.management. In general, it is also difficult to mechanize the actual planting operation.operation. But there is wide scope for improvement, in terms of quantity andand quality.quality. There are also a number of adjunct activities in addition toto actual planting, many ofof which couldcould bebe improved.improved. Examples of such activities are:are: transportingtransporting seedlingsseedlings fromfrom thethe nurserynursery toto the planting area, and thenthen carryingcarrying themthem fromfrom thethe roadroad toto thethe actualactual planting site, clearing thethe planting area,area, marking plantingplanting rows,rows, weedingweeding and tending after the planting, and transplantingtransplanting whenwhen necessary.necessary. In this section all but the firstfirst activity (transport(transport ofof seedlingsseedlings toto plantingplanting area) will be coveredcovered briefly.briefly. - 135 -

Very often the planting activities are conducted on land with difficult terrainterrain andand poorpoor accessibility.accessibility.

Workers maymay havehave toto walk longlong distancesdistances toto reachreach thethe plantingplanting area.area. They normally have toto carrycarry thethe seedlingsseedlings onon footfoot fromfrom thethe roadroad toto thethe planting site.site. When using pottedpotted insteadinstead ofof bare-rootbare-root seedlings,seedlings, bigbig amounts of heavy soilsoil areare carriedcarried asas well.well. The total weight to be carried during one working day cancan be considerable.considerable. Improving the seedling carrier is one wayway to facilitate the transport work. whenWhen thethe seedlingsseedlings areare toto bebe carriedcarried longlong distances, andand particularly when thethe terrainterrain isis steepsteep and rough,rough, a back-pack model isis preferable (see(see FigureFigure 33),33), or a packpack animal.animal.

OÀ\0.¡#\on' )01/x fi

1 111,1181

Figure 33. WhenWhen the seedlings are toto be carried long distances andand when thethe terrain is steep and rough,rough, a back-pack carrier will facilitatefacilitate the transport work. - 136 -

When itit comescomes toto thethe actualactual treetree planting,planting, thethe seedlingsseedlings cancan bebe stored in a suitable plant tray which is carried in the hand between the plaa suitable plant tray which is carried in the hand between the planting sites and put down on the ground when doing the planting (Figure(Figure 34a), or in a shoulder-carried seedlingseedling containercontainer (Figure(Figure 34b).34b).

Figure 34a. AA plant tray, carried in the hand between the planting sites and put down when planting, will also help to protect the plants fromfrom drying.

Figure 34b.34b. A shoulder-carriedshoulder-carried seedlingseedling container.container. - 137 -

Ideally, the workers should be equipped withwith a planting hoehoe ofof the appropriate typetype forfor thethe particularparticular soilsoil and terrainterrain they are planting at the moment.moment . For example, if the planting site isis stonystony andand very difficult,difficult, they shouldshould havehave aa so-called50-called "grubbing"grubbing mattock" - seesee FigureFigure 35 (ILO's(ILO' 5 Forestry EquipmentEquipment PlanningPlanning Guide, p.121),p.121), andand ifif thethe planting sitesite isis on a steep slope thethe plantingplanting tooltool shouldshould havehave a shortershorter handle than when working onon flatflat terrain.terrain. In the Philippines, different hand toolstools forfor planting (among(among otherother forestryforestry activities)activities) have been compared and evaluated in an ILOILO study.study.

Figure 35.35. Different types of planting hoes designed forfor various terrainterrain and soil.soil. When planting onon aa steepsteep slopeslope aa short-handledshort-handled tooltool is preferable (upper(upper hoe).hoe). When the planting site isis stonystony and very difficult aa "grubbing"grubbing mattock"mattock" shouldshould bebe usedused (lower(lower tool).tool) . - 138 -

Two workwork studies were undertaken which dealt withwith tree planting in the context of an industrial plantation and aa government reforestation project, respectivelyrespectively 1/.1/. Both compared different handhand toolstools forfor planting;planting; one of them also evaluatedevaluaed thethe effecteffect ofof usingusing ordinaryordinary marketmarket basketsbaskets toto augment the number of seedlingsseedlings that can be carried from the roadside to the planting site.site.

The mostmost satisfactory planting tool for general purposes waswas an oval-blade planting hoehoe (Figure(Fi~re 36).36). The oval-blade hoehoe penetratespenetrates thethe soil moremore easily than aa bladebla~ with aa straightstraight edge.edge. Unlikeunlike the wooden dibble (Figure(Figure 37), it does not leave an air pocket under the seedling, or compact the~soil soil onon allall sidessides ofof thethe plantingplanting hole.hole. Finally, thethe oval-blade hoe's cutting edge curves around the sides of the blade to facilitate patch clearing inin dense grassland.grassland.

In the government reforestation project, the oval-blade hoe increased the planting raterate by 22% above that of a military-type spade in easy terrain, and by 35% above that of the narrow-blade planting hoe in difficult terrain.

Figure 36. Removing thethe grass and humus layerlayer with oval-bladeoval-blade plantingplanting hoe.

~/1/ Workwork StudiesStudies 66 andand 7,7, ChoiceChoice ofof AppropriateAppropriate TechnologyTechnology inin PhilippinePhilippine Forestry (1981).(1981). - 139 -

Figure 37.37. Tree planting with wooden dibble.dibble.

The clearingclearing ofof thethe plantingplanting area,area, asas well asas thethe weedingweeding andand tendingtending activites, could also be improvedimproved and facilitatedfacilitated byby thethe introductionintroduction ofof appropriate tools.tools.

The all-purpose , bolobolo oror junglejungle ,knife, oftenoften mademade ofof materialmaterial of poor quality, isis the tooltool used also forfor thethe activitiesactivities mentioned above.above. The short-handled tooltool must be used inin a bent andand inconvenientinconvenient work posture.

Each separate tasktask will inin generalgeneral bebe carriedcarried outout with lessless effort,effort, faster, better and more safely when using toolstools designed speciallyspecially forfor thethe task. The workers themselvesthemselves cannotcannot affordafford three,three, fourfour oror eveneven more different tools.tools. But forfor thethe enterprise,enterprise, thethe costcost cancan usuallyusually bebe afforded,afforded, especially when consideringconsidering thethe benefits.benefits.

Figure 38 shows some different toolstools used forfor cleaning,cleaning, weeding andand tending. Tools with a new andand different designdesign andand aa newnew wayway ofof functioning, when comparedcompa·red to thethe traditional toolstools thethe workers are used toto working with,with, willwill needneed alsoalso aa newnew workingworking technique.technique. It will be decisive for the acceptance of the new tools,tools, as well as forfor production, efforteffort and safety, that workers are given appropriate trainingtraining on thethe use and maintenance of thethe new tools.tools. This is often overlooked. The attitude thatthat hand tools are so simplesimple toto use thatthat nono trainingtraining isis neededneeded isis farfar tootoo prevalent. - 140 -

(kg -

~ IQ O

Figure 38. Different tools with varying design to be used forfor cleaning, weeding andand tending.tending. - 141 -

Tree planting workwork isis usuallyusually consideredconsidered neitherneither heavyheavy nornor dangerous,dangerous, but steep and roughrough terrain,terrain, longlong walkingwalking distances,distances, heavyheavy loadsloads toto carry,carry, and strenuous and unergonomic work postures due to poor tool design often make thethe planting work heavy.heavy. These working conditions,conditions, inin combinationcombination with a hot climateclimate andand oftenoften directdirect exposureexposure toto radiantradiant heat,heat, increaseincrease thethe risk of heat stress.stress. It is important to organize the work in such a way that this riskrisk isis avoided.avoided.

Shelters shouldshould bebe provided.provided. Drinking water or other liquids should be available. Work during thethe hottesthottest hours ofof thethe day shouldshould be avoidedavoided and work should preferablypreferably bebe concentratedconcentrated inin thethe coolercooler morning hours. Transport of thethe workers betweenbetween dwelling and plantingplanting areasareas shouldshould bebe provided ifif possible,possible, toto savesave theirtheir energy.energy. Workersworkers shouldshould havehave appropriate footwearfootwear toto helphelp avoidavoid falling,falling, steppingstepping onon sharpsharp objects, and snake bites. Tools should be properly maintained, e.g. sharpened and loose handles fastened.fastened. Workers shouldshould notnot workwork tootoo nearnear eacheach other.other.

6.4 Logging Operations

Logging operations includeinclude aa numbernumber ofof variousvarious workwork elementselements suchsuch as:as:

(1) Walking inin thethe forest,forest, with or without tools.tools. (2) Use of hand toolstools andand chainsaws.chainsaws. (3) Maintenance and repairrepair of tools, equipment andand machines. (4) Clearing of paths, escape routesroutes and thethe base of treestrees fromfrom undergrowth andand otherother obstructions.obstructions. (5) Felling operations includingincluding takingtaking downdown hung-uphung-up trees,trees, debranching, cross-cutting and moving and bunching of logs.logs.

The most hazardous taskstasks are felling and debranching, particularly when theythey are donedone byby chainsaw.chainsaw.

(1) Walking

The workers are exposed to certain hazards when walking inin the forest, and on arrival at or departure fromfrom theirtheir workplace, especially ifif theythey havehave toto carrycarry tools,tools, aa chainsawchainsaw oror heavyheavy loads.loads. Walking forfor longlong distancesdistances inin aa hothot climateclimate andand inin ruggedrugged terrainterrain should be restricted, as much as possible, soso as not to cause unnecessary fatiguefatigue toto thethe worker.worker. The worker should not walk alone.alone. At least one ofof thethe workersworkers shouldshould havehave aa first-aidfirst-aid box.box.

Paths and workplaces shouldshould be kept clear fromfrom obstacles inin order to prevent stumblingstumbling andand falling.falling. The worker shouldshould wear appropriate boots toto protect thethe feetfeet fromfrom injuries,injuries, inin casecase ofof steppingstepping onon protruding sharpsharp objects,objects, andand toto preventprevent slippingslipping andand falling.falling. Good footwear will also provideprovide protectionprotection fromfrom snakesnake bitesbites andand leeches.leeches.

Frequently-used paths should be cleared of branches and plants which may strikestrike thethe worker.worker. In particular, plants whichwhich areare poisonouspoisonous oror thorny should be removed.removed.

A safety helmet must alwaysalways bebe worn toto protectprotect thethe headhead ifif therethere isis aa danger of fallingfalling branches.branches.

When sharp-edgedsharp-edged oror sharp-pointedsharp-pointed toolstools areare carried,carried, theythey shouldshould bebe equipped with protective coverscovers oror sheaths.sheaths. If not covered, thethe tooltool should be carried as safelysafely asas possible.possible. Generally, itit should be - 142 -

gripped near the cutting part and kept close to the body, with the sharp edge parallel to thethe leg,leg, oror pointing outwards.outwards.

When carryingcarrying aa chainsaw,chainsaw, thethe engineengine shouldshould be stoppedstopped andand thethe chainbar covered with a guard, except for short distances as during crosscutting and limbing,1imbing, or when the distance between trees to be felled isis veryvery short.short.

Tools for chainsaw maintenance should preferably be carried in a tool belt.

In order to save energy and to free the hands, loads should, whenever possible, be carriedcarried onon thethe back,back, e.g.e.g. inin aa rucksack.rucksack.

(2) Use of handtools and chainsaws

A major part ofof injuriesinjuries inin forestforest work occur when handling hand tools and chainsaws.chainsaws. Many of these accidents are caused by direct accidental contact betweenbetween thethe humanhuman bodybody andand thethe tool/thainsaw.too1/chainsaw. TheThe worker may, forfor example, strikestrike himself with thethe bolobolo (machete),(machete), or axe because thethe tooltool slipped.slipped. Safe working techniques areare crucialcrucial toto avoid accidents and unnecessary physicalphysical strain.strain. Below, onlyonly somesome very general precautions forfor using handhand tools and chainsawschainsaws will be mentioned. Detailed guides on, e.g., the use and maintenance of chainsaws; proper working techniques for felling operations, are therefore recommendedrecommended forfor furtherfurther study.study. See nos. 4,4, 22,22, 3737 andand 3939 in the referencereference list.list.

- Hand toolstools

The appropriate tooltool shouldshould alwaysalways bebe usedused forfor thethe job.job. For example,example, an axe should neither bebe usedused asas aa wedgewedge nornor asas aa logpick.lcigpick. Whenever possible, dangerous toolstools shouldshould be replacedreplaced with lessless dangerousdangerous ones. A handsaw, for example, is safer than an axe when felling trees (and(and saves human energyenergy andand woodwood waste).waste).

Dangerous cutting tools,tools, suchsuch asas axes, billhooks (bolos),(bolos), sawssaws andand barking spudsspuds shouldshould have asas safesafe a design asas possible.possible. , billhooks and similarsimilar cuttingcutting toolstools shouldshould have handleshandles with .aa projection toto prevent thethe hand fromfrom slippingslipping ontoonto thethe blade.blade. A correctly designed axe handlehandle isis shownshown inin SectionSection 3.2.1,3.2.1, FigureFigure 23.23. The workers should be trainedtrained toto use thethe tooltool oror chainsawchainsaw inin thethe right mannermanner byby usingusing proper workingworking techniques so as to avoid poorpoor work positions, and reducereduce staticstatic work and harmful lifting.lifting. They should start under easy working conditions until they are skilled in its use. Safe behaviour should be emphasized,emphasized, suchsuch as:as:

- never cut with a sharp tooltool towardstowards thethe body; - keep the stem between thethe tooltool andand your legs,legs, e.g.e.g. ifif debranchingdebranching with an axe or chainsaw, oror debarking with aa barking spud,spud, andand alwaysalways keep at a safesafe distancedistance fromfrom otherother people.people.

- never throw a tool toto another person,person, but alwaysalways handhand itit overover inin aa safe way; - 143 -

- always keep tools in a safe place when not using them, so as to prevent steppingstepping on,on, oror fallingfalling overover them.them. For the same reason tools, or at least their handles, should be painted in colours different fromfrom thethe surroundingsurrounding environment;environment;

- never use a tool oror chainsawchainsaw ifif itit isis not inin good condition; always use iti t following thethe manufacturer's recommendations,recommendations, ifif any - thisthis is particularly importantimportant whenwhen usingusing aa chainsaw.chainsaw.

- always use guards forfor sharpsharp toolstools duringduring transporttransport andand storage.storage.

Figure 39.39. Workwork with thethe stemstem betweenbetween thethe tooltool andand yourself!yourself!

- Chainsaws

Chainsaws can cause both frequentfrequent and severesevere occupationaloccupational accidentsaccidents and diseases. Common hazards directly relatedrelated toto thethe chainsawchainsaw are:are:

- the workerworker cuts himself, usually on the hands, fingers, feet or legs;

- kickbacks, causing severesevere cutscuts or leadingleading toto indirectindirect injuries,injuries, e.g.e.g. the workerworker falls because of the kickback and gets hurt by a sharp object; -- 144144 --

- chain breaks, usually injuring the rightright hand, but separate loose cutters or linkslinks may also intrude on the body, leading to even fatal injuries. A well-maintained chain,chain, properly sharpened,sharpened, tensionedtensioned andand lubricated, will considerablyconsiderably reducereduce thethe riskrisk ofof aa chainchain break;break;

- noise (see(see sectionsection 3.2.2).3.2.2).

- vibration (see(see sectionsection 3.2.3).3. 2.3).

Before startingstarting thethe chainsaw,chainsaw, itit shouldshould bebe takentaken awayaway fromfrom wherewhere itit was filledfilled upup withwith fuel.fuel. It should be placed on firm ground beforebefore starting up toto preventprevent itit fromfrom slipping.Slipping. The ground should bebe cleared of obstacles which otherwise might be caught by the chain and cause aa kickback.kickback. No other person than the operator mustIIlUSt be within a two-metre distance.distance.

Figure 40a40a and bb showsshows differentdifferent startingstarting techniques.techniques.

10, f

e '41 flyAr Y41

aspwaseggfr

Figure 40a. How to start thethe sawsaw whenwhen placedplaced onon thethe ground.ground. - 145 -

Figure 40b. How to start the saw when holding it between the knees.

The chainsaw operator should stand with the legs well apart and one foot forward when using thethe saw.saw. A firm stand will reducereduce the riskrisk of slipping, which is a common cause of accidents. The saw should be kept close toto thethe bodybody andand bebe supportedsupported onon thethe legslegs oror treetree (see(see Figure 41).41).

Figure 41. The saw should be kept closeclose toto thethe body andand bebe supportedsupported on the legs oror tree.tree. - 146146 --

To reducereduce the risk of kickback, the upper part of the guidebar nose should not be used (see(see FigureFigure 42).42).

Figure 42.42 . To reducereduce the riskrisk of kickback, the upper part of the guidebar nose shouldshould notnot bebe used.used.

To prevent serious injuries,injuries, thethe chainsaw operator must wear a safety helmet with eye and ear protection, safetysafety boots, gloves and leggingsleggings.. A first-aid pocket pocket kit should kit be included should in thebe personal included in the personal protective equipment. equipment.

(3) Maintenance andand repairrepair ofof tools,tools, equipmentequipment andand machines

Well-maintained toolstools andand equipmentequipment areare lessless likelylikely toto causecause accidents, and cause less physical strain than those in poor condition. Inspections for general condition and sharpness should be carried out regularly.regularly. Broken or looseloose handleshandles of toolstools shouldshould be replaced as soonsoon asas possiblepossible toto avoidavoid unnecessary,unnecessary, butbut common,common, accidentsaccidents.. CUttingCutting tools should be kept sharp, so that the worker can rely on them and be able to use an efficient and safe working technique.technique.

In an Indian study (Hansson(Hansson et al., 1966), the significance of maintenance of two-mantwo-man crosscutcrosscut sawssaws onon thethe outputoutput ofof workwork andand onon energy expenditureexpenditure waswas tested.tested. The output of work, using a well-maintained saw,saw, was more thanthan 100%100% higher,higher, andand thethe energyenergy expenditure was 120% lower,lower, comparedcompared toto thethe meanmean valuesvalues ofof fivefive badly-maintained saws.saws.

Chainsaws shouldshould receivereceive regularregular (daily(daily andand weekly) maintenance following the manufacturer's recommendations.recommendations.

Each user of tools,tools, chainsaws,chainsaws, equipmentequipment oror machinesmachines shouldshould preferably be given sufficientsufficient trainingtraining toto bebe ableable toto carrycarry outout maintenance andand simplesimple repairrepair work.work. To do maintenance work forfor a while will give thethe worker onon a physicallyphysically heavyheavy tasktask aa restrest pause,pause, while at the same timetime beingbeing productive.productive. It willwill break monotony and make the workers more independentindependent ofof repairrepair andand serviceservice organizationsorganizations in their work. - 147 --

After use, thethe toolstools shouldshould be carefullycarefully cleaned and put inin a safe place. Responsibilities for maintenance, cleaning and repair should be made clearclear amongamong workmen.workmen.

Many accidents occuroccur duringduring repairrepair work.work. Situations will arise which often are newnew forfor thethe worker.worker. Some reasons for frequent accidentsaccidents inin repair work are:are:

- lack of experience andand awarenessawareness ofof safetysafety risks;risks; - proper toolstools andand aidsaids areare notnot availableavailable oror notnot used;used; - time pressure.

(4 ) Clearing paths, escape routesroutes and base of trees toto be felledfelled of undergrowth and other obstructionso strucbons

This can be physically heavy work, particularly if carried out inin a hot climate, inin ruggedrugged terrainterrain andand withwith densedense undergrowth.undergrowth. The worker will be exposed toto thethe samesame hazards as mentioned under (1)(1) and (2) •

To protect themselves fromfrom leeches,leeches, snakes, poisonous plants and those causing allergic reactionsreactions when touched the workers shouldshould wear clothes of stoutstout material,material, withwith longlong sleevessleeves andand leggings.leggings. Boot-tops and trousers shouldshould overlap.overlap. Gloves should be used toto protect thethe hands from sharp splinters fromfrom plants, sharp edges, thornsthorns and the like.

The workers should be informedinformed about locallocal dangerous plants,plants, animalsanimals and insects, how toto identifyidentify them,them, and how to apply first-aid,first-aid, ifif affected.

(5) Felling operations, includingincludin takindown hung-up trees, debranching, cross-cutting, and moving and bunching of logs

Whatever tooltool oror machine isis usedused forfor fellingfelling operationsoperations andand relatedrelated activites such as debranching and cross-cutting,cross-cutting, thethe worker must be given sufficient training,training, under closeclose supervision,supervision, inin safesafe and efficient working techniques.techniques. Tree fellers have one of thethe most, ifif not thethe most, hazardous jobsjobs inin forestry. Tree felling causescauses frequentfrequent accidentsaccidents eacheach year.year. Many of them are severe or fatal.fatal. This is true regardless of mechanization level, climate, terrain and other relevant working environment factors.

A skilledskilled worker who isis awareaware ofof safetysafety risks,risks, whowho usesuses well-maintained toolstools (and(and when usingusing aa chainsaw,chainsaw, isis equippedequipped withwith safetysafety devices), and who wears appropriate personalpersonal protectiveprotective equipmentequipment isis lessless likely to suffer from severe occupational accidents and diseases. Common types of accidents are, e.g. that the tree fallsfalls inin the wrong direction or backwards. This isis often causedcaused byby sawingsawing throughthrough thethe fellingfelling combcomb oror byby aa poor notch. It is alsoalso common that the butt end of the tree is thrown upwards, hitting thethe worker. This is usually because the worker is standing too close to the tree after finishingfinishing thethe fellingfelling cut,cut, oror duedue toto poor escape routes.routes. - 148 -

It is also common that fellers suffer from pain in the back, neck and certain jointsjoints caused by theirtheir heavy and strenuous work. In many cases the worker would bebe helpedhelped byby applyingapplying thethe correctcorrect techniquetechnique forfor liftinglifting and carrying loads.loads. The use of levers, hooks andand logpickslogpicks facilitatesfacilitates thethe workwork when fellingfelling small-diametersmall-diameter trees.trees. (Figure(Figure 43).43).

Figure 43. In many cases thethe worker would prevent work-related pain in the back, neck and jointsjoints byby applyingapplying aa betterbetter techniquetechnique when liftinglifting andand ....(see...• (see nextnext page)page) - 149149 -

Figure 43 (cont'd.)...carrying(cont'd.) ... carrying loads. The use of levers, hooks and log-picks also facilitates the work.

--...!::--='~'------. ~ - .. - - . --.-:::,,~

la,J.<' .>------1.81-8m m ------....J..jO.lmf..10.2m -

- 150 -

Taking down hung-up trees is the most hazardous jobjob a feller has to do. ItIt should be givengiven much attentionattention during thethe trainingtraining of forest workers.

A hung-up treetree leftleft hanginghanging . isis aa fatalfatal traptrap andand every attempt shouldshould be made toto taketake itit down,down, withoutwithout delay.delay. Many forestforest workers have suffered severe or fatal accidents because of using unsafe methods when taking downdown lodged trees, suchsuch as:as:

felling thethe treetree inin which thethe hung-uphung-up treetree isis caught;caught; felling another treetree ontoonto thethe hung-uphung-up tree;tree; - cutting shortshort piecespieces ofof thethe lowerlower partpart ofof thethe hung-uphung-up tree.tree.

These methods areare usuallyusually practised because when theythey work they are faster than other, safersafer methods. However, they may not work, but resultresult in a fatal accident instead.instead.

A lodged treetree isis alwaysalways extremelyextremely dangerous.dangerous. The work of takingtaking itit down should only be started after the situation has been thoroughly evaluated, so as to decide on the safest method to be used. The proprirpro~r methodmethod may be one ofof thethe following.following. After cutting any remainingremaining brancbran~es, es, preferably with anan axe:axe:

- roll the tree free by using tools such as lifting hooks, felling lever (with cant hook), turn-line or cant hook - if the tree is small. (Figure(Figure 44).44).

- with the help of a sulky,sulky, lift the treetree up fromfrom thethe stumpstump and pull it down. (Figure(Figure 45).45).

- pull the butt end backwards, using a push pole - ifif thethe treetree is small. (Figure(Figure 46a).46a).

When thethe treetree isis bigger,bigger, aa draughtdraught animal,animal, aa tractor-mountedtractor-mounted winch or portable winch may bebe thethe solution.solution. (see(see FiguresFigures 4646 b,b, cc andand d).3). - 151 -

A.A,

e

Figure 44. Different tools which cancan be used forfor rollingrolling small trees.trees. A. Lifting hook; B.B. FellingFelling lever;lever; C.C. TurnTurn line.line. D.D. CantCant hook.hook. r

- 152 -

Figure 45.45. A hang-up sulkysulky forfor freeingfreeing of lodged trees.trees.

Figure 4646 a.a. When thethe treetree isis small:small: useuse aa pushpush polepole andand pullpull thethe butt end backwards.backwards. - 153 -

~iguresFigures 4646 b andand c.c. When thethe treetree isis bigger, useuse aa tractor-mountedtractor-mounted winch oror portableportable winch.winch. - 154 -

Figure 4646 d.d. Never leaveleave a lodgedlodged tree without marking the danger area clearly.clearly.

The followingfollowing areare toolstools whichwhich areare neededneeded forfor safesafe andand efficientefficient work:work:

- a bolo (or(or machete) with protective cover - wedges of softsoft metal oror wood - hammer toto drive wedges intointo big treestrees - axe with protective covercover - cant-hook

- felling lever with cant-hookcant-hook ) - for small - hooks and tongstongs ) trees

The chainsaw shouldshould have safetysafety devices suchsuch as:

- front handle guard with chain brake to protect the left hand and to stop the saw inin case ofof aa kickbackkickback (1),(1),

- chain catcher toto catchcatch thethe chainchain ifif itit breaks (2),(2),

- rear handle guard to protect the right hand if the chain breaks (3)(3), ,

throttle control lock out toto preventprevent thethe chainchain fromfrom runningrunning accidentally (4),(4),

- anti-vibration devices, toto reducereduce vibration beingbeing transmittedtransmitted toto hands (5),(5),

- guide bar cover to prevent injuriesinjuries (cuts)(cuts) during transport,transport, storage or walking with chainsawchainsaw (6)(6) (see(see FigureFigure 47).47). - 155 -

1

Figure 47. Safety devices on the chainsaw. (1)(1) Front handle guard with chain brake, (2)(2) Chain catcher;catcher; (3)(3) RearRear handlehandle guard;guard; (4) ThrottleThrottle control lock out; (5)(5) Anti-vibration devices;devices; (6) GuideGuide bar cover.cover.

6.5 Loading and unloading

Manual bunching, extraction,extraction, loadingloading andand unloadingunloading areare heavyheavy andand dangerous activities with obviousobvious risksrisks ofof occupationaloccupational accidentsaccidents andand diseases.

Common causes of accidents are slipping, fallingfalling and stumblingstumbling over obstacles. Paths and timbertimber yards shouldshould thereforetherefore be kept clearclear of obstacles, holes, overhanging branchesbranches and thethe like.like. The workers shouldshould wear properproper boots.boots.

Other causescauses ofof accidentsaccidents areare thethe toolstools andand aidsaids used,used, oror notnot used,used, or used inin thethe wrong manner.manner. The use of adequate tools and equipment and appropriate working techniquestechniques (e.g.(e.g. straightstraight backback when lifting)lifting) will facilitate the work andand decreasedecrease thethe riskrisk ofof backback trouble,trouble, muscularmuscular strain,strain, bursitis, unnecessary fatiguefatigue andand waste of .energy,energy, whereas usingusing inappropriate tools for the job, such as using an axe for pulling or lifting, or using tools inin poor conditioncondition (a(a bluntblunt ratherrather thanthan aa sharpsharp tool, tools with broken handles) will lead toto accidents (such(such asas cutscuts inin the leg or foot, or load dropped onto thethe foot,foot, due toto tooltool slipping).slipping).

Manual handling of heavyheavy loadsloads shouldshould bebe avoidedavoided whenever possible,possible, particularly when working inin a hot and humid climate,climate, being exposedexposed toto radiation, workingworking long hours, or if workers are malnourished or under-nourished. Instead,Instead, mechanicalmechanical aidsaids forfor lifting,lifting, loadingloading andand unloading shouldshould bebe used.used. When organizingorganizing thethe work,work, effortsefforts shouldshould bebe mademade to facilitate the work by means of scheduling of working hours and breaks, manpower planning andand jobjob rotationrotation inin casescases wherewhere itit isis notnot possiblepossible toto entirely avoid manual liftinglifting andand carryingcarrying (see(see FigureFigure 48).48). - 156156 --

itt44111Aor , rAfor v, MOM MUUM pLe.thizej MUM MUMM3

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AM aft4ft Aft O ...... AI ma.alla Aleraft INA4At, I WIND rllJAM

1400,641

Figurerigure 48. DifferentDifferent ways ways ofof loading,loading, unloading unloading and and movingmoving loads. - 157 -

Although mechanical loadingloading andand unloading will considerablyconsiderably decrease the physical workloadworkload and the risk of occupational accidents and diseases for mostmost workers,workers, new risks of serious accidents willwill occur for certain tasks. Accidents causedcaused byby lossloss ofof stabilitystability and componentcomponent failurefailure areare particularly common.common. Mechanization of almost any job requires more training ofof the workers, more planning by supervisors and management, and a strict enforcement of safety regulations, e.g. a safe distance between loadingjunloadingloading/Unloading operations and persons not directlydirectly involved must be ensured. No loadload mustmust passpass overover anyany person.person. Landings must have sufficient space and be kept clear toto ensureensure safesafe operations.operations. All workers at thethe workplace must be aware of thethe signalsignal systemsystem practised. Equipment which may cause an accident when worn out, damaged or failing to run normally should always be treated as a safety risk, and never be trusted asas safe.safe.

Equipment must be checkedchecked regularlyregularly forfor wearwear andand damage.damage. Responsibilities for keeping equipment and materials inin safe working condition must be clearlyclearly stated.stated. For instance, the anchoring ofof winches, the condition of brakes and handles on winches, and other materials such as wire ropes,ropes, chains andand chokerschokers must bebe checkedchecked regularly.regularly.

Transport When aa number ofof workersworkers carrycarry logslogs together,together, thethe . workingworking techniquetechnique and signals used for lifting and dropping the load, or walking and stopping walking should be specifiedspecified beforebefore startingstarting thethe work. New crewcrew membersmembers should be made aware ofof thethe signals.signals. Signals should be given byby thethe worker furthest to the rearrear ofof thethe load.load.

As already stated,stated, manualmanual handlinghandling ofof heavyheavy loadsloads likelike logslogs shouldshould bebe restricted. However, skiddingskidding sulkiessulkies areare a reasonablereasonable solutionsolution forfor manual transport over shortershorter distances.distances.

For terrain transport, animals may also be a good solution.solution.

Tractors and trucks of various levels of mechanization and with different equipment are frequentlyfrequently used inin transporttransport operationsoperations inin forestry. The physical workload isis generally moderate toto lowlow forfor thethe machine driver. A helper may, however, consumeconsume up toto fivefive timestimes asas muchmuch energy as the driver, when requiredrequired toto pullpull thethe cablecable fromfrom aa tractor-winchtractor-winch over long distances inin roughrough andand steepsteep terrainterrain toto reachreach thethe logs.logs. The work of the driver involvesinvolves many safetysafety andand healthhealth hazardshazards which dodo notnot existexist inin manual work. Noise, vibration, heat andand exhaustexhaust gasesgases areare somesome commoncommon ergonomic problems accompanying mechanization.

Maintenance andand repairrepair workwork areare particularlyparticularly dangerousdangerous andand causecause aa considerable number of accidents in machine operations. Besides risksrisks of accidents affecting thethe operator,operator, thethe risksrisks forfor otherother personspersons workingworking nearnear the machine and equipment will often increase when an operation isis mechanized.

Whenwhen operating aa tractor,tractor, thethe driverdriver shouldshould bebe protectedprotected inin casecase thethe tractor overturns or if falling logs, branches, flying lines,lines, or other obstacles come into thethe cabcab fromfrom above,above, oror fromfrom thethe side.side. A cabcab withwi th frame, roof and windows with metal grating of sufficient strength toto resistresist impact willwill decrease the risk of injuryinjury from such incidents. Furthermore, it should be easy to get on and off the tractor by means of anti-slip - 158 - steps, platforms and handholds, with sufficient cab space and correct placement of thethe seat.seat. When the operator has to work both inside the cab and on the ground, e.g. if operating a winch, and therefore is frequently climbing in and out,out, easyeasy accessaccess isis important.important. It is also necessary forfor safety in emergencies, e.g.e.g. firefire causedcaused byby thethe machine.machine.

The seat shouldshould bebe comfortablecomfortable andand safelysafely anchored.anchored. It should absorb oscillations of different frequency.frequency. Seat, pedals, controls and instruments should be so designed and placed as to give the operator a comfortable work posture, with possibilities for adjustment to suit most of the people likely toto operateoperate thethe machine.machine.

The controls' resistanceresistance to being moved should match the working position and muscular mass involvedinvolved toto prevent fatiguefatigue and over-strained muscles.

The instruments should be of a suitable type giving all necessary information.

Poor visibility from the operator's position over the working area may cause accidents.accidents. It may also cause fatigue and pain ifif thethe operatoroperator isis forced to get intointo awkwardawkward positionspositions inin orderorder toto obtainobtain betterbetter visibility.visibility.

The operator should be sufficiently trained to be capable of not only operating thethe machine safelysafely and efficiently,efficiently, but also carrying outout maintenance and minor repairs.repairs. Condition of brakes, winches, cables,cables, ropes, transmission, clutchesclutches and otherother partsparts mustmust bebe checkedchecked regularly.regularly. Proper toolstools and equipment forfor thisthis must be readilyreadily available.

The worker should also be trained to plan his various tasks and be familiar with the use of simple checklists in order not to overlook any factor. At work the operator should wear a safetysafety helmet, hearing protectors, boots with anti-slip soles,soles, tight-fittingtight-fitting clothes, andand glovesgloves if handling wires, cablescables andand ropes.ropes. Injuries to the handshands caused by broken wires may lead toto blood poisoning.

Passengers for whom there is no safe seat should not be allowed on the tractor or trailer.trailer. Log trucks used forfor long distance transport on public roadsroads must comply with national requirementsrequirements regardingregarding suchsuch itemsitems as lights, warning and signallingsignalling devices.devices.

6.6 Other Activities in ForestryForestsv In Sections 6.1 to 6.5, some of the most common forestry activities have been discussed fromfrom an ergonomicergonomic pointpoint ofof view. Forestry does not comprise these activities only, butbut a numbernumber ofof otherother operations asas well. Some of them involveinvolve very specialspecial risks,risks, forfor example,example, forestforest firefire fightingfighting and timber floating,floating, which will bebe briefly dealt with here.

6.6.1 Forest fire fighting

Forest firefire fightingfighting isis extremelyextremely demandingdemanding work.work. Forest fires often have to be foughtfought inin remoteremote and isolatedisolated areasareas andand inin roughrough terrain,terrain, where conditions may be very poor and where ad hoc solutionssolutions (such(such asas medicalmedical care) must be foundfound forfor emergency situations.situations.

Only workers who are healthy and physically fitfit should be selectedselected for this job.job. They will need physical trainingtraining asas well as specializedspecialized first-aid training in which the particular risksrisks in fire fighting are - 159 - stressed, for example: burns,burns, thermalthermal overload,overload, heatheat stress,stress, dehydration,dehydration, carbon monoxidemonoxide poisoning, and also learn how to recognize such behaviour of their workmates which couldcould indicateindicate thatthat they are affected inin a harmful way by e.g. heat, carboncarbon monoxide oror fatigue.fatigue. They shouldshould bebe awareaware ofof thethe importance of rest periods and sufficient intake of liquids and food to maintain a sustainedsustained workingworking capacity.capacity.

The workers should be trained in the understanding of the basic principles ofof forestforest firefire behaviour.behaviour. They should be well awareaware ofof whatwhat thethe conditions and factorsfactors are which cancan lead toto sudden changes of thethe behaviour ofof thethe fire.fire. It is often the sudden changes which causecause thethe accidents (also(also thethe fatalfatal accidents)accidents) and the near-accident situations.situations.

Clothing Forest fire fighters should wear clothes and equipment which will provide somesome protectionprotection againstagainst firefire andand heat.heat. The cloth shouldshould bebe cotton,cotton, wool and/orand/ or canvas when specialspecial flame-resistantflame-resistant clothing isis not available. Synthetics and cloth of mixed material shouldshould not be worn ifif theythey contain more than 15 percentpercent nylonnylon oror polyester.polyester. There is always thethe riskrisk thatthat such cloth will meltmelt andand causecause burns.burns. Oily clothes must never bebe worn. Shirts should be long-sleeved, and thethe legslegs of the trousers shouldshould reachreach the top of boots, so as not toto leave any part of the arms and legslegs unprotected. The safety helmet should be made of heat-resistant material as well as thethe footwear.footwear. Gloves areare recommended.recommended.

Organization Fire control organization has to be effective and requires experienced and safety-mindedsafety-minded personnel.personnel. Escape routes for everyone and safety islands should be planned and theythey have to be made known. Special lookouts should be posted whenever there isis a riskrisk of great danger. All communication should be prompt and clear and be checked thatthat itit has been understood - misinterpretations cancan bebe fatal.fatal. Crew leaders shouldshould bebe familiar with the terrain, which isis particularly important when therethere are steep slopes, narrow valleys and gullies. This type of topography can create dangerous situations as thethe firefire can speed up very fastfast and traptrap the firefighters. Other conditions which cancan givegive riserise toto veryvery unpredictable,unpredictable, and therefore dangerous, behaviour of fire are when the firefire isis burning in highly inflammable areas, and when there are variable winds. The risk of heat stress disorders and carbon monoxide poisoning should also be takentaken into account when organizingorganizing firefire control.control.

Heat stress In Section 3.1.1. "Climate", heat stress disorders have been described and fire fighters were mentioned as a high-risk group.group.

Thermal overload has a much shortershorter lapselapse thanthan heat strokestroke (described(described in that section), but can lead toto the person being totallytotally incapacitatedincapacitated within less thanthan aa minute. underUnder such strenuous conditions thethe work organization should be adapted, e.g.e.g. inin the formform of a rotationrotation systemsystem of the workers in thethe most exposedexposed positions.positions. - 160 -

Carbon monoxide

The rotationrotation system is particularly important to avoid carbon monoxide poisoning.poisoning. The effets of carbon monoxide areare insidiousinsidious andand thethe workers themselvesthemselves will not be aware of how theirtheir mental capacity deteriorates.

It is essential that the crew leaders be experienced and wellwell aware of the very special risksrisks involvedinvolved inin thethe workwork ofof controllingcontrolling forestforest fires.fires.

6.6.2 Timber floating

In many countries, waterways have long been used for the transport of timber. Different methods and techniques are used when floating loose timber or bundles of logslogs (rafts)(rafts) onon rivers,rivers, lakeslakes oror sea.sea.

Some workplaces are permanent,permanent, suchsuch asas log-pondlog-pond landings.landings. Others areare mobile, such as raftraft building on land alongside thethe waterways and inin thethe water, or thethe actualactual floatingfloating andand guidingguiding ofof looseloose timbertimber oror rafts.rafts. The working andand livingliving conditionsconditions areare diverse.diverse.

All workers engagedengaged inin timbertimber floatingfloating · -- bothboth thosethose at thethe permanentpermanent workplaces andand thosethose who areare mobilemobile -- shouldshould knowknow howhow toto swimswim andand howhow toto give artificial respiration.respiration. They should never work out of hearing and sightsight of other workers.workers.

The workersworkers should wear safety jackets and footwear with non-slip soles.

Boats should be inin good condition andand bebe well-maintained and operated only by experienced workers.workers.

The maximum number of persons and loadload allowed shouldshould be clearly stated and nevernever bebe exceeded.exceeded. There should be suitable life-saving equipment and thethe workers shouldshould bebe trainedtrained inin howhow toto actact when someonesomeone falls overboard.overboard. They shouldshould know what toto dodo ifif thethe boatboat capsizes,capsizes, e.g.e.g. take off anyany heavyheavy itemsitems suchsuch asas heavyheavy clothingclothing andand boots.boots. It is usually safer to hold on toto thethe boatboat oror otherother floatingfloating objectsobjects thanthan toto trytry toto swimswim a long distance, particularly inin roughrough oror coldcold water oror with aa current.current.

Other constructions,constructions, e.g.e.g. booms,booms, bridgesbridges andand gangways,gangways, shouldshould bebe designed inin suchsuch aa wayway asas toto allowallow thethe workwork toto bebe carriedcarried outout safely.safely. There should, forfor example, bebe enoughenough spacespace forfor safesafe movementmovement andand forfor twotwo workers toto passpass eacheach other,other, surfacessurfaces shouldshould bebe eveneven withoutwithout protrudingprotruding objects, there shouldshould bebe supportssupports toto holdhold onon toto atat dangerousdangerous spots,spots, andand sufficient life-saving equipmentequipment shouldshould bebe within easyeasy reachreach atat strategicstrategic places.places.

6.7 Wood Processingprocessing

Ergonomic matters which areare brieflybriefly discusseddiscussed inin thisthis sectionsection willwill refer mainly to sawmilling, wood-based panelpanel industries,industries, carpentry,carpentry, joineryjoinery and furniturefurniture making.making.

A wide rangerange ofof technologiestechnologies areare usedused inin woodwood processing,processing, includingincluding the most advanced large-scale wood-based panelpanel industries,industries, different sizessizes of modern sawmillssawmills asas wellwell asas smallsmall pit-saws,pit-saws, andand artisansartisans usingusing onlyonly - 161 -

Figure 49.49. pit-sawingPit-sawing.. handtools inin furniturefurniture making.making. The ergonomic problems discussed belowbelow willwill by no means be a completecomplete listlist ofof hazardshazards inin allall thesethese industries,industries, butbut willwill serve as examples of some common safety and health problems.problems.

Besides frequent accident risks,risks, many jobsjobs inin thethe processing industries involveinvolve risksrisks ofof seriousserious occupationaloccupational diseases.diseases. For examplexample,e, the use of glues, and chemicals in wood industriesindustries involvesinvolves health hazards.hazards. Also dust and other toxictoxic constituentsconstituents originatingoriginating fromfrom thethe wood give rise to possiblepossible risks.risks. Growing attention in industrialized countries is beingbeing paid to relatedrelated occupational diseases.diseases. But inin many countriescountries there is still an apparent lack of awareness of these problems.

6.7.1 AccidentAccident risks and preventive measures

Woodworking machines Woodworking machines constitute oneone major agentagent ofof occupationaloccupational accidents in the processing industry,industry, causing about one-thirdone-third ofof allall injuries (Philippines, 1977-1981). The majority of injuries occurring in woodworking concern a fewfew basic machines, namely circular saws, , spindlespindle moulders, planersplaners andand chainsaws. - 162 -

1. Circular saws

Accidental contactcontact betweenbetween hand andand sawsaw andand kickbackkickback of wood are possible, resulting in serious accidents, if sawblades are inadequately guarded.

/ ' , / /

Figure 50a.SOa. 'rtleThe sawblade must not bebe unguarded.unguarded.

Figure 50b.SOb. The sawbladesawblade shouldshould alwaysalways bebe guarded.guarded. - 163 -

For length sawing (rip-sawing)(rip-sawing) machines, the saw blade cover should be adjustable. The saw blade should have guards also underunder the table to prevent accidentalaccidental contactcontact withwith thethe saw.saw. Handles, pedals and steering wheels shouldshould bebe atat aa minimumminimum distance,distance, ofof atat leastleast halfhalf aa metre, fromfrom sawsaw andand feedfeed rollers.rollers.

Proper sawsaw bladeblade maintenancemaintenance andand feedfeed speedspeed willwill alsoalso improveimprove safety.safety. The most commoncommon typetype ofof cross-cuttingcross-cutting sawsaw isis thethe pendulumpendulum sawsaw mounted aboveabove the saw bench.bench. The saw blade should be covered with a self-adjusting guard. After cross-cutting, a countercounter weight should returnreturn thethe saw blade to ' a safe positionpoSition behindbehind thethe guideguide .fence. Start and stop controls should be within easyeasy reach,reach, butbut at aa safesafe distance fromfrom thethe sawsaw blade.

2. Band saws

Safety rulesrules areare very muchmuch likelike thosethose forfor circularcircular saws.saws. Both upper and lower band wheels shouldshould be covered,covered, asas well as thethe rearrear sideside ofof thethe blade. Guides should be adjustable inin height and the cover shouldshould followfollow the height adjustment.adjustment. A brake,brake, toto stopstop thethe bladeblade afterafter thethe powerpower isis switched off,off, shouldshould bebe availableavailable withinwithin easyeasy reach.reach. Maintenance and frequent checks for any defects of saw blades are important preventive measures.

3. Spindle moulders

The purpose of using spindle moulders is to shape wood edges toto patterns of varying designs.designs. The cutter works at very high speed andand should therefore be enclosed, toto prevent worker's contactcontact with thethe tooltool and exposure toto wood dustdust oror chips.chips. The machine should also be equipped with protection againstagainst kickbackkickback ofof wood.wood. A brake,brake, toto stopstop thethe cuttercutter afterafter thethe power isis switchedswitched off,off, shouldshould bebe withinwithin easyeasy reach.reach.

4. Planers The most dangerous planers areare thethe hand-fed surfacesurface planers.planers. An adjustable table guard should protect thethe hand fromfrom contactcontact with thethe .tool.

General commentscomments

There are numerous other wood-working machines not mentioned here.here. However, thethe generalgeneral safetysafety rulesrules thatthat shouldshould bebe consideredconsidered areare thethe following:

- moving or projecting parts must be provided with guards;guards;

a brake, to stop moving parts after thethe power isis switchedswitched off,off, shouldshould be within easy reachreach inin case of emergency;

- the importance of proper maintenance of toolstools andand fittings,fittings, properproper tensioning and sharpening should be recognized,recognized, asas well as thethe importance of operating machinery at appropriate speeds;

- only persons who are properly trainedtrained and familiarfamiliar with thethe machine should be allowed toto operateoperate it;it; - 164 -

- new operators should receivereceive adequate training from skilled and safety-minded persons;persons;

- maintenance andand repairrepair shouldshould bebe carriedcarried out only after thethe power has been switched off andand when nono partsparts areare moving;moving;

- maintenance andand repairrepair shouldshould onlyonly be carried out by qualified personnel, usingusing properproper tools;tools;

- proper personal protectiveprotective equipmentequipment suchsuch as gloves, hard hat, eye and ear protection, apron,apron, boots and other equipment shouldshould be used where appropriate.appropriate.

Plantplant layout, materials handling and housekeeping A highhigh percentagepercentage ofof accidentsaccidents areare relatedrelated toto thethe handlinghandling ofof goodsgoods and transport ofof material.material. "Falls", "stepping or striking against",against", and "struck by falling objects" areare commoncommon immediateimmediate casuescasues ofof accidents.accidents. But the real causes of suchsuch accidents usually originate fromfrom poor layout of worksites or storagestorage places,places, oror poorpoor housekeeping.housekeeping.

To attain aa safesafe andand smoothsmooth workflow, thethe successionsuccession ofof work operations must bebe carefullycarefully planned.planned. All work operationsoperations shouldshould be ensured sufficient space.space. Plant layout shouldshould allowallow peoplepeople andand vehicles,vehicles, or other means of transportationtransportation of material,material, toto move freely and without risks of collision. These movements shouldshould be separatedseparated fromfrom eacheach other.other. Whenwhen this isis notnot possible,possible, warning signssigns shouldshould indicateindicate transporttransport lanes,lanes, and vehicles should have back-up alarms toto cover the driver's blind spots. Lifting equipment should have maximum loading signs.

All tools,tools, equipmentequipment andand machinesmachines usedused forfor materialsmaterials handlinghandling shouldshould be regularlyregularly inspectedinspected forfor damagedamage oror wearwear andand tear,tear, andand mustmust bebe properlyproperly maintained.

To avoid slipsslips and falls,falls, stairs,stairs, cross-overs,cross-overs, walkways andand laddersladders should be kept clear.clear. The measurements of stairs and walkways and handles shouldshould bebe . suchsuch asas toto allowallow adequateadequate spacespace forfor feetfeet andand bodybody movements and firmfirm bodybody position.position. The floor should be made ofof non-slipperynon-slippery material and shouldshould bebe keptkept freefree fromfrom obstacles.obstacles.

The work area shouldshould be keptkept cleanclean and freefree fromfrom looseloose boards,boards, offcuts, shavings, sawdustsawdust and grease. Housekeeping must never be left to chance but responsibilities and organization forfor thisthis shouldshould be well-planned andand strictlystrictly followed.followed. Good housekeeping isis anan inexpensiveinexpensive way of preventing accidentsaccidents asas wellwell asas toto improveimprove productivity.productivity. OtherOther areasareas where housekeeping andand carefulcareful planningplanning willwill improveimprove safetysafety andand productivity are inin loglog andand lumberlumber yards.yards. ForFor instance,instance, pilespiles mustmust bebe stable to avoid logslogs rollingrolling oror lumberlumber falling.falling.

Also forfor thethe avoidanceavoidance ofof fire,fire, goodgood housekeepinghousekeeping isis necessary.necessary. In all wood-processing industriesindustries therethere isis a riskrisk of fire,fire, particularlyparticularly inin particles suchsuch asas wood dust,dust, shavingsshavings oror chips.chips. In these materials therethere is a risk of self-igniting due toto internalinternal overheating. Engines may also get overheated ifif coveredcovered withwith dust.dust. Strict rules should be followed regarding housekeeping, smoking, thethe use of open firesfires oror highlyhighly inflammableinflamable chemicalschemicals andand materials.materials. - 165 -

Figure 51.51. To avoid slips and fallsfalls there shouldshould bebe cross-overscr08s-overs andand walkways atat strategicstrategic places.places. - 166 -

The organization of firefire fightingfighting should be thoroughly planned as regards employees' training and responsibilities,responsibilities, locationlocation andand regularregular checks of firefire fightingfighting equipment.equipment.

Installation, maintenance and repair of electrically-poweredelectrically-powered woodworking and otherother machines, equipment,equipment, wiring and cablescables shouldshould be carried out by qualified electricians.electricians.

Nature of injuriesinjuries andand partsparts of bodybody injuredinjured

According toto statisticsstatistics fromfrom thethe Philippines,Philippines, thethe predominantpredominant injuries are lacertions (in more than 50 percent of cases), bruises and haematoma (in(in almostalmost one-thirdone-third ofof thethe cases).cases). Injuries were mostly to fingers, feetfeet andand head.head. About 40%40% ofof thethe injuriesinjuries affectedaffected fingers,fingers, handshands and arms, about 25% feet,feet, toestoes andand legs,legs, and more thanthan 10%10% thethe head. If appropriate personal protective equipment,equipment, such as gloves, boots and helmets had been used, a considerableconsiderable part of these 75% of thethe accidents might have been avoidedavo!.ded entirely, or at least the injuriesinjuries may have been less severe.severe.

6.7.2 Health risksrisks and preventive measures Based on statisticsstatistics availableavailable fromfrom different countries,countries, occupationaloccupational diseases are much less frequent thanthan occupational accidents inin the processing industry. On the other hand, according to the samesame sources,sources, they are more serious. However, this does not necessarily representrepresent the true picture of actual conditions. Definitions of occupational diseases are usually vague and varying and very often the relationships between a disease and certain environmental factorsfactors are still unknown. It also takes longer to develop anan occupationaloccupational disease.disease.

Noise and vibration

Impaired hearing caused by noise has a clear definition, and can easily be attributed to a too-high sound level at the place of work. Hearing impairment is also the most frequent occupational disease in the wood-processing industries,industries, accordingaccording toto statisticsstatistics inin manymany countries.countries.

Most woodworking machines produce a very high soundsound level.level. High-speed cutting tools usually produce harmful, high-frequency noise. There are also many other sources of noise such as transport systems, falling planks, hard materials clashing together, vibrating plates, ventilation systemssystems andand compressors.compressors.

Hand-arm vibration diseases do not seem to be a very commoncommon problem in the wood-processing industry.industry. When chainsaws areare usedused therethere will,will, however, be a risk of vibration inducinginducing white fingers. Whole body vibration isis reportedreported toto bebe aa problemproblem forfor many sawmillsawmill workers.workers. The most commonly found vibration is in the rangerange of 1-20 Hz and may cause dizziness, nauseanausea andand headache.headache. The combination of a standing job-posturejob-posture and vibration may lead toto varicosevaricose veins.veins.

In Sections 3.2.2 and 3.2.3,3.2.3, occupational diseases causedcaused by noise and vibrationvibration and their prevention are described more thoroughly.thoroughly. - 167 -

Woodwood dust andand toxictoxic woodwood constituentsconstituents

As alreadyalready mentioned,mentioned, woodwood dustdust increasesincreases thethe riskrisk ofof firesfires andand explosionsexplosions.. It maymay also cause skin irritation, allergic reactions, toxic effects, respiratoryrespiratory diseasesdiseases andand cancer.cancer.

- Skin irritation isis mainlymainly causedcaused byby mechanicalmechanical reaction.reaction. The reaction may be caused by sap, oilsoils,, resins, turpentines, bacteria or naturally-occurring fungi.fungi. If dustdust comes into contact with thethe eyes,eyes, nose or throat, itit may give riserise toto tears,tears, sneezingsneezing or asthma-like symptoms.

- Allergic reactionreaction maymay appearappear afterafter repeatedrepeated exposure,exposure, causingcausing reactions similar to those mentionedmentioned above, or itching throat and nose, high feverfever andand headache.headache.

- Toxic effects, suchsuch as locallocal skin and eye irritation,irritation, may be the result of contact with containingcontaining certaincertain poisonouspoisonous substances.substances. Severe health effects from inhalation of from such wood are anaemia, liver disease, depressed heart action, nausea and vomiting. Most of thesethese woods areare ofof tropicaltropical origin.origin. - Respiratory diseasesdiseases areare particularlyparticularly commoncommon amongamong employeesemployees inin thethe furniture industry.industry. Very finefine dust, which isis extremely irritantirritant toto the respiratory tract,tract, isis produced inin large quantities when wood is sanded. The exposure to a variety of wood dusts may cause diseases such as bronchial asthmaasthma andand fibroidfibroid lung.lung.

- Cancer of thethe lung,lung, tonsils,tonsils, tongue,tongue, nasalnasal passagespassages andand larynx,larynx, mostmost probably due toto exposureexposure toto wood dust, havehave beenbeen reportedreported primarilyprimarily in the furniture industry.industry.

Preventive measures areare dustdust collectioncollection andand efficientefficient systemssystems ofof exhaust ventilation at wood dust-producing machines or operations.operations. When this is not possiblepossi~le thethe worker must wear personal respiratoryrespiratory equipment. Employees exposed toto wood dust shouldshould have regularregular medical examinations.

Chemicals, glues and solventssolvents

A largelarge varietyvariety ofof chemicalschemicals areare usedused toto preservepreserve woodwood fromfrom beingbeing destroyed by mouldsmoulds andand insects.insects. These chemicals may be applied by brushing, spraying, immersion,immersion, osmosis or injection.injection. As thethe useuse ofof thesethese chemicals involves different health risks,risks, direct contactcontact with themthem shouldshould be avoided.avoided. Irritation of the skin and eyes, bronchitis, allergic reactions, andand even severe poisoning have been reported as affecting the workers handling thesethese chemicals.chemicals. The application of chemicals should always be done inin enclosedenclosed systems.systems. Even when an enclosedenclosed systemsystem isis used,used, there is still the possibility of contact between thethe worker andand chemicalschemicals due toto leakageleakage ofof vapourvapour oror mists,mists, oror spillingspilling fromfrom defectivedefective containers.containers.

New chemicalschemicals areare introducedintroduced toto thethe marketmarket everyevery year.year. veryVery often the effect of these on health isis not known. Such chemicals should allall bebe treated with thethe greatestgreatest care.care. - 168 -

Another factorfactor causing health problems, particularly in veneer, plywood and particle-board manufacture, is the use of glues, particularly artifical ones.ones. Most of them are made of synthetic adhesives based on formaldehyde and thethe neopreneneoprene adhesives.adhesives. Besides skinskin diseases, allergicallergic reactions, and chronic eczemaeczema from directdirect contact,contact, these glues maymay causecause systemic intoxication.intoxication. At lowlow concentrationsconcentrations ofof formaldehydeformaldehyde inin thethe air,air, the eyes and upper respiratoryrespiratory tracttract willwill bebe irritated.irritated. If concentration increases, the problems becomebecome moremore severe.severe. The eyes, nose andand tracheatrachea will burn and thethe eyes startstart watering. The exposed person will have difficulty inin breathing and may get severesevere spasmodic coughing. If high concentration isis inhaledinhaled itit maymay bebe fatal.fatal.

Where glues,glues, paintspaints andand areare used inin thethe processingprocessing industries, there will also be the use of various solvents .such as alcohols, ethers,ethers, glycolglycol derivatives,derivatives, turpentine,turpentine, etc.etc. Irritation of mucous membrane and skin are commoncommon problems. Some solvents also lead toto allergic reactionsreactions and eczema, and may even affect thethe central nervous system. Benzine, tetrachlorethane and carbon tetracholoride are examples of highly toxictoxic solventssolvents whichwhich shouldshould notnot bebe used.used.

Preventive measures to protect workers from occupational· diseases caused by toxictoxic chemicalschemicals cancan bebe carriedcarried outout by:by:

- changing the dangerous chemicals for less hazardous ones to the health; - enclosing processes where harmful substances are in use; - installing effective ventilationventilation andand washingwashing facilities.facilities.

All workersworkers who maymay bebe exposedexposed toto dangerousdangerous chemicalschemicals shouldshould bebe givengiven proper information,information, instructions,instructions, andand trainingtraining onon howhow toto handlehandle thethe chemicals, and on the necessity of using personal protective equipment,equipment, personal hygiene,hygiene, andand emergency treatmenttreatment inin casecase ofof accidentalaccidental exposure.exposure . Personal protective equipment such as protective clothing, rubberrubber boots, aprons and gloves,gloves, faceface shields,shields, respiratoryrespiratory masksmasks oror anythinganything elseelse which may be appropriate, shouldshould bebe worn. The provision and maintenance ofof personal protectiveprotective equipment, suchsuch asas cleaningcleaning andand regularregular checkschecks forfor damage or leakage,leakage, shouldshould bebe organized.organized. First-aid equipment and treatment should be available and exposed workers should have periodic special medical examinations.examinations. workWork postures and movements workersWorkers inin thethe wood processingprocessing industryindustry usuallyusually havehave toto workwork inin standing or walking postions, very often without any chance to sit down even.for aa shortshort while.while. Many jobs,jobs, particularlyparticularly inin smallsmall oror oldold plants,plants, are physically heavy.heavy. But even when jobsjobs are not heavy, theythey may leadlead to severe occupational diseases such as tenosynovitis (inflammation(inflammation of tendons). Due to shortshort work cyclescycles with rapid,rapid, repititiverepititive movements, inin unergonomically designed workplaces, tenosynovitistenosynovitis occursoccurs frequentlyfrequently inin thethe hands, wrists andand forearms.forearms. Low back pain and headaches areare otherother commoncommon problems.

Another inflammatoryinflammatory effecteffect isis bursitis.bursi tis. Here, the parts of the body that are most commonly affected are the elbow and knee jointsjoints due to repeated pressure on joints.joints. If frequently carrying heavy loads,loads, suchsuch asas timber or lumber, workers may get bursitis in their shoulders.shoulders. - 169169 -

Ergonomically designeddesigned workplaces with suitablesuitable work heights, well-placed controls andand panels, enough space,space , and the availability of appropriate tools, machines and other aids can solve many of thesethese problems.

6.7.3 Other ergonomic factorsfactors

Lighting

Insufficient lightinglighting isis commoncommon inin thethe wood-processingwood-processing industries.industries. Besides too-lawtoo-low lighting levels,levels, glare from unshaded lamps or poor location of lamps and windows maymay troubletrouble thethe worker.worker. veryVery often the worker himself is not aware of poor lighting being the cause of his fatigue, headaches and inability to concentrate.concentrate. Unsuitable lighting may result in low quality and quantity of work andand increasedincreased accidentaccident risks.risks. Such a ·simple measure as regular removal of dust fromfrom lamps and windows may improve lightinglighting conditions considerably.

Climate

Ventilationventilation maymay bebe necessarynecessary toto reducereduce heatheat stressstress whenwhen thethe climateclimate is hot and humid. Drinking water should always be within easy reachreach so that the workers do notnot havehave toto waitwait untiluntil longerlonger breaksbreaks forfor drinking.drinking.

Stress and mental workload

monotonous,Monotonous, repetitiverepetitive jobsjobs with nono possibilitiespossibilities forfor thethe workerworker toto control his own work pacepace oror workwork method;method; limited contacts with colleaguescolleagues due to noise, distance, work pace oror becausebecause thethe workers areare tiedtied toto theirtheir individual workwork places:places; and night or shift work are some of thethe factors in the wood-processingwood-processing industry which may cause "psychosomatic"psychosomatic problems". Changes of work design andand work organization may helphelp toto improveimprove ·thethe psycho-social effectseffects fromfrom thethe workwork environment.environment.

7. THE USE OFOF ERGONOMICERGONOMIC CHECKLISTSCHECKLISTS

7.17. 1 Background andand ObjectivesObjectives

A checklist isis notnot aa substitutesubstitute forfor knowledge,knowledge, butbut provesproves toto bebe moremore valuable the more experienced thethe user is.is. No matter how experiencedexperienced and knowledgeable a person is,is, aa checklistchecklist isis indispensableindispensable forfor ergonomicergonomic evaluation and analysis.analysis. The use of checklists will prevent the risk of overlooking any ergonomic aspect of importanceimportance forfor thethe evaluation.evaluation. It will also provide comparable data fromfrom studiesstudies and analysisanalysis conductedconducted byby different persons, at different timestimes and of different objects.objects.

A checklistchecklist willwill proveprove usefuluseful when:when:

- assessing new design ofof tools,tools, machines,machines, equipment,equipment, etc.;etc. ; - assessing new work organizationsorganizations andand techniques;techniques; - assessing entire workplaces, includingincluding tools,tools, machines,machines, equipment, work organization,organization, methods andand techniques;techniques; - purchasing tools,tools, machines, equipment,equipment, etc.;etc.; - conducting safety inspections;inspections; - teaching ergonomicsergonomics.. - 170 -

For certain .analyses, it willwill be necessary to carry outout supplementary measures, applying more sophisticatedsophisticated methods and instruments,instruments, forfor instanceinstance when analyzinganalyzing noisenoise exposure,exposure, physicalphysical workloadworkload oror nutritionalnutritional conditions.conditions. Very often, however,however, well-prepared and well-designed checklists, includingincluding interviews, will provide sufficient information about the workingworking conditions to be evaluated. The objectives of an ergonomic checklist, when used for problem surveys, or inin thethe planning andand designdesign process,process, are:are:

- to ensure a logical and systematic study of the problem to be solved; - to maximize the chances of gathering only the relevant and important data and background information;information; - to minimize thethe riskrisk ofof missingmissing anyany ofof it;it; - to assist inin thethe decision process,process, wheneverwhenever possible.possible.

For operational management, a checklist is used as a tool for gathering qualitative ratherrather thanthan quantitativequantitative data.data. The objective is,is, then, not to get material sufficientsufficient forfor statisticalstatistical analysis, but toto get a general overview of thethe working conditions, enabling thethe user toto pin-pointpin-point critical conditions. The conditionsconditions identifiedidentified as unacceptable,· or sub-optimal, should then become thethe . object ofof furtherfurther studies. ItIt might be necessary to consultconsult experts forfor conductingconducting furtherfurther studies, and findingfinding solutions toto thethe problems.problems.

Generally, all checklistschecklists shouldshould includeinclude interviewsinterviews with involvedinvolved parties. The studied worker and supervisorssupervisors are persons who should be considered as experts on theirtheir own working conditions.conditions. If the interviews are carried out carefully with a respectfulrespectful and open mind, they will always prove to be an invaluableinvaluable sourcesource of information.information. They will also prevent misinterpretation of data gathered using other methods and techniques.

7.2 Required Conditions

To get thethe best out ofof aa checklistchecklist study,study, thethe followingfollowing requirementsrequirements should be met:met: - the user of 'the checklist should be knowledgeable, experienced and well-prepared; - the user of the checklist should aim at objectivity and preferably have an independentindependent relationshiprelationship with involvedinvolved parties;parties;

-a thoroughthorough introductionintroduction shouldshould bebe givengiven toto everyoneeveryone concerned,concerned, oror toto representatives of e.g. management, employees, safety and medical departments, regardingregarding background,background, objectivesobjectives andand proceduresprocedures ofof thethe study, e.g. methods to be used, how findingsfindings will be presented and utilized, ifif and how thethe studystudy will bebe followedfollowed up;up;

- the approval of all parties should be obtained before the studystudy starts; - the attitude of persons who might not agree to participate inin thethe study, particularly in an interview,interview, shouldshould be respectedrespected and fullyfully accepted; - 171 -

- sufficient time should be allowedallowed forfor observationsobservations andand interviews,interviews, and for making additional notes, comments, photographs or sketches related to items covered inin thethe checklist;checklist;

- a quiet environment and a relaxedrelaxed atmosphere during the interviews should be ensured;

- no listeners or onlookers should be present during the interviews;

- the interviewer and interviewee should preferably speak the same language so as to avoid the presence of a third person, an interpreter, during thethe interview;interview;

- after the interview is completed, the interviewed person should be provided with a contact address, in case he/she would like to change or add to anything saidsaid duringduring thethe interview;interview;

- any follow-up or feedback activity promised, e.g. during the introduction or thethe interview,interview, mustmust taketake place.place. Future cooperation from involved parties cannotcannot otherwiseotherwise bebe expected;expected;

- sufficient time should be set aside for the analysis of the information as soonsoon asas possiblepossible afterafter itit hashas beenbeen gathered.gathered. Notes, sketches, etc., and particularly notes from interviews, should always be interpreted byby thethe personperson who producedproduced them;them;

- group interviews should only be conducted by persons with experience of such, as group interviewsinterviews alwaysalways involveinvolve a riskrisk ofof gettinggetting only the official opinion, or the opinion of the "leader", which is not necessarily thethe opinion ofof thethe groupgroup as a whole.

As mentioned earlier,earlier, anan ergonomicergonomic checklistchecklist cancan alsoalso serveserve asas aa useful teachingteaching aidaid inin ergonomicsergonomics training.training. Preferably, thethe checklistchecklist willwill be used towardstowards thethe endend ofof thethe training.training. The exercise will provide the trainees with an opportunity to apply learned theories and practices under realistic conditions. The exercise will also serve as a check-up, for both trainer and traihees,trainees, of what has been learned or perhaps misunderstood. It will give an indication of what kind of further training isis needed.

An example ofof anan ergonomicergonomic checklist,checklist, originallyoriginally developeddeveloped forfor training purposes, has been includedincluded inin this handbook.

The checklist is fairlyfairly comprehensivecomprehensive and may thereforetherefore alsoalso be appropriate forfor other purposes,purposes, mentioned earlier.earlier. It can be used by followingfollowing the general "instructions" discussed in this section.section. Some additional "instructions""instructions" applicableapplicable toto thisthis particular checklistchecklist may,may, however, bebe useful.useful.

7.3 How to use thethe ChecklistChecklist

The checklist is designed to be used forfor only one worker/job at a time, as each worker, with a specificspecific job,job, isis unique. So there must bebe oneone checklist forfor each worker/jobworker/job toto bebe studied.studied. - 172 -

Before starting toto fillfill inin thethe checklist:checklist:

- make aa schemaschema ofof thethe totaltotal processprocess flow.flow. Indicate wherewhere the different workplaces areare located.located. The schema will familiarize thethe checklist user with the production process, as wellwell as being useful for the reportingreporting ofof thethe study;study; - make a simple drawing, or take photographs of the studied worker and his workplace.

- photographs takentaken of work postures, tools,tools, aids, etc. may also proveprove useful.

- write a jobjob description forfor thethe studiedstudied worker.worker .

- before each question, indicateindicate whether thethe question can be answered solely by observations, if the observations shouldshould be completed with an interview, and when the question has to be answered by the information given during thethe interview.interview.

The symbols usedused are:are:

ID -= interview desirable to complement observations

IN = interview necessary

- Start with thethe observations,observations, answeringanswering allall unmarkedunmarked questions.questions. This should preferably bebe donedone withoutwithout disturbingdisturbing thethe worker.worker. Continue thereafter with the interview and answer all questions marked ID and IN.

- In most cases the entire checklist can be used, as the items which are not applicable will drop out when followingfollowing the instructions saying "if NOT, see...."see • •.. " or "if"if YES see ...."..... " .

- Additional informationinformation will alwaysalways bebe necessarynecessary from,from, e.g.e.g. management, medical and safetysafety departments, representativesrepresentatives ofof tradetrade unions oror workers' associations.associations.

- After each sectionsection therethere isis aa spacespace forfor "Comments""Conunents" which shouldshould bebe used forfor any remarksremarks andand informationinformation ofof relevancerelevance toto thethe subjectsubject ofof each particular section.section. Improvements and changeschanges which areare neededneeded or desirable should be noted down. Unusual or new solutions to problems which havehave already beenbeen successfullysuccessfully appliedapplied may bebe citedcited as good examples.

- Mark each itemitem forfor which measures shouldshould bebe takentaken toto improveimprove thethe conditions. Circle the number ofof thethe item.item. Items for whichwhich measures are urgent shouldshould bebe marked inin aa very distinctdistinct way, e.g.e.g. byby marking with a noticeable colour.colour. - 173173 -

7.4 Ergonomic ChecklistCheckList for WorkplacesWorkpLaces

TASK: • ..• ••• • ••.•••.•• •.•• ••••••• •••• ENTERPRISE:. • •••.••••. ••• •••••• ••• •

WORKPLACE: ••• •. •••• •••• ••• • •• ••••• ••• MAIN ACTIVITY-ACTIVITY: ......

WORKERWORKER'S' S NAME.NAME: •• • •••••••• • ••• • •••.•• • No. of Male Female employees WORKER'S AGE-AGE: •••••••••••••••••••••••• Office NAME OF CHECKER.CHECKER: •••.• • •••••••• •• ••••• Production DATE:DATE: •••••••••••.••••••••••••••••••••

DRAWING OF WORKPLACE (Provide a simple drawingdrawing ofof thethe workplaceworkplace underunder study.study. Mark the positionposltlon ofof the worker and pointpoint outout thethe positionposition ofof machines/equipment/materials.)machines/equipment/materials.)

DESCRIPTION OFOF TASKTASK (List activities performedperformed byby thethe workerworker underunder studystudy andand estimateestimate timetime inIn percentagepercentage spentspent onon differentdifferent activities.)activities . ) - 17417/, --

LEGENDLEGEND::

1101IIDI = Interviews desirable to supplementsupplement observationsobservations

IINIIIN1 = Interviews necessary

11. . WORKING POSTURESPOSTURES YES NO

1.1 SittingSi tting ..

1.2 Sitting/standing (changeable)(changeable)

1.3 Standing ......

1.3.1 Can the job be done sitting oror sitting/standing? (specify)(specify) ...... •.....

1.3.2 Is a chair available during shortshort breaks?breaks?

1.4 Standing/walking

1.4.11.4. 1 Is a~chaira,chair available during shortshort breaks?breaks?

1.5 Chairs:

1.5.1 Is the chair well-designed (regarding(regarding height,height, 'seat,·seat, armarm-- andand back-support)? ......

1If f not, comments ......

1.5.21.5.2 Is the chairchair adjustable?adjustable? 1.51.5.3. 3 Is aa footrest available? EE 1.6 Does thethe jobjob imply:imply:

1.6.1 Free choice of working position?position? f--.--f---l 1.6.2 A fixed position? r--i--- 1.6.31. 6 . 3 Static muscle work?

1.6.4 One-sided and unsymmetrical movements?movements ? -_.- ---- 1.6.5 Frequently-repeated movements without variety?va r iety? f-_ .------1.6.6 Complicated work patterns? .... --_._- .- 11.6.7.6.7 Uncomfortable oror tiring movements (e.g(e.g.. workingworking with arms above shouldersshoulders or head, twisting, bending, stooping)?stooping)? ~ ------"- ---' - 175 -

IINI1INI 1.7 Suggestions for improvement (related(related toto itemsitems 1.1- 1.6)1 .6)

2. TOOL(S) ANDAND EQUIPMENTEQUIPMENT YES NO

2.1 Are any tool(s)/equipment used byby thethe worker?worker? ....

If NO, continue atat 3.3.

If YES, replyreply to questions 2.2-2.8.2.2-2.8.

2.2 Which tool(s)/equipment are used and forfor whichwhich task(s)?

1101MI 2.3 How frequentlyfrequently is/are thethe tool(s)/equipmenttool(s)/equipment usedused (con-(con­ tinuously, often, occasionally, rarely)?rarely)?

YES NO 110111D1 2.4 Are the tool(s)/equipment appropriateappropriate forfor performingperforming the task? ......

If not, state why (e.g. too heavy, inappropriateinappropriate design, etc.)etc.)

YES NO

1IIDI101 2.5 Are tools fitted with adequate "handles? handles?

110111D1 2.6 Are tools properly maintained?

IIDI1101 2.7 Can the job be performed more easily/moreeasily/more efficientlyefficiently

by using any additional/other tool(s)/equipment?tool(s)/equipment? . .

If yes, which tool(s)/equipment andand forfor whichwhich task(s)?task(s)? ...... -- 1761 76 --

!IN'IINI 2.8 Suggestions for improvementimprovement (related(related toto itemsitems 2.1-2.1- 27)2.7) ......

3. CONTROLS AND DISPLAYS YESYES NO

3.1 Are any controls or displays used byby thethe worker?worker?

If NO,NO, continuecontinue atat 4.4.

If YES, replyreply toto questionsquestions 3.2-3.9.3. 2-3.9.

3.2 Which:

controls?

displays?

1101IIDI 3.3 How frequently are the controls/displays used?used?

YES NO

IINI 3.4 Is it easy to operate the controls? . ..

1101IIDI 3.5 Has the function of the controls/displays beenbeen

clearly indicated, and isis itit understandable?understandable? . .

1101IIDI 3.6 Is the operator adequately informedinformed aboutabout thethe function of the controls/displays?

1101IIDI 3.7 Have the controls/displays beenbeen setset upup logicallylogically and conveniently? ......

1101IIDI 3.8 Can the job be performedperformed more easily/moreeasily/more efficientlyefficiently

by using any additional/other controls/displays? . .

IINI 3.93.9 Suggestions for improvementimprovement (related(related toto itemsitems 3.1-3.1- 33.8). 8) - 177177 -

4. PHYSICAL WORKLOADWORKLOAO (should(should preferablypreferably bebe supplementedsupplemented by measurement) YES NO

4.1 Is the work physically veryvery heavy mostmost ofof thethe time?time?

4.2 Not very heavy most of thethe time,time , butbut withwith peakspeaks ofof very heavy work'work? . . . . .

4.3 Mention thethe heaviestheaviest workwork elements:elements: ......

YES NO

4.4 Light work most of thethe workingworking timetime . ..

IINI 4.5 Worker's opinion of thethe physicalphysical workloadworkload (4.1-4.4)(4.1-4.4)

IINIITN( 4.6 Suggestions forf or improvementim proveme nt (related(related toto itemsitems 4.1-4.5)4.1-4.5)

5.5. MANUAL LIFTING,LIFTING,CAR~YING, CARRYING, PULLING AND PUSHING

5.1 Does thethe jobjob imply:imply: YES NO

55.1.1. 1 . 1 manual lifting'lifting?

5.15.1.2 .2 manual carrying'carrying?

5.1.3 manual pulling'pulling?

5.1.4 manual pushing'pushing?

If NO,NO , continue atat 6.6.

If YES, reply to questions 5.25.2 andand 5.3.5.3. - 178 -

110ilD11 55.2. 2 Give aa briefbrief description ofof thethe burdens:burdens:

weight: ......

shape:shape- ......

frequency of handlinghandling (per(per hour).hour) : ......

distance ofof handling:handling :

IIININI1 5.35. 3 Suggestions forf or improvementimprovement (related( related toto itemsitems 5.15.1 andand 5.2)5.2)

6. VIVISIBILITYSIBILITY ANDAND LIGHTINGLIGHTIN G YES NO 11D1110 1 66.1. 1 Is visibilityvisibility adequate (regarding( regarding workwork posture,posture , safetsafety,y, fatigue,fat i gue, efficiency)?effic iency) ? ......

66.2. 2 Is the workplacewor kp lace litlit byby artificialartifi cial oror naturalnatural light?light?

...... ' ......

66.3. 3 What kind of artificial lightlight source?source?

66.4. 4 If the workplace is1S litlit byby (a)(a) lamp(s),lamp(s), isis thethe workerworker disturbed by:by: YES NO

110IDI I 6.4.16 . 4.1 flflickering ickering of the lamp?lamp?

1ilDi101 6.4.26. 4.2 too much contrast?

IID!1101 6.4.3 fluctuation of bright and dark inin hishis visual field?

110IIDI I 6.4.4 glare or reflection?reflection?

IINIlIN I 6.56. 5 According to the worker, is1S thethe workplaceworkplace wellwell lit?Ii t? . lINIINI I 6.6 Suggestions for improvementimprovement (related(related toto itemsitems 6.1-6.5)6.1-6.5) ...... -- 179 -

77.. NOISE (should(should preferablypreferably bebe supplementedsupplemented byby measurement)measurement) YES NO 7.1 Is the worker exposed toto noise?noise? . . -,-----J If NO, continue atat 8.8.

If YES, reply to questions 7.2-7.11.7.2-7.11.

I1D11101 7.2 What is/areis/are thethe source(s)source(s) of the noise?noise?

1101IID1 7.3 For how longlong perper dayday isis thethe workerworker exposedexposed toto noise?noise?

hours/day

7.4 Is the noise continuouscontinuous oror intermittent?intermittent?

YES NO

7.5 Is there noise ofof impulse-type?impulse-type? . . .

IN 7.6 lIN I 7.6 Is the noise disturbing, accordingaccording toto thethe worker?worker? . EE IIf f yes, inin what way?way?

YES NO

7.7 Can the noisenOIse source(s)source(s) bebe eliminated? ......

If yes, how?how?

YES NO

7.8 Can the noisenOIse source(s) bebe isolated?isolated?

IIf f yes, how?

YES NO

7.9 Does the worker wearwear ear protectors?protectors?

If yes, what kind?kind? ......

IINIIIN I If no, why not? ...... - 180180 --

YES NO 1101MI 7.10 Are there any audible warningwarning signals oror otherother audible communications necessary toto performperform thethe job?job? IINIIN If yes, can the workerworker hearhear them?them? ...... rn ITN!IINI 7.117.11 Suggestions for improvement (related(related to items 7.2-7. 2- 7.10)

......

8. VIBRATIONVI8RATION YES NO

8.1 Is the worker exposedexposed to vibration'vibration? ......

If NO, continuecontinue atat 9.9.

If YES, replyreply to questions 8.2-8.8

8.2 What kind ofof vibration:vibration: YES NO

8.2.1 hand-arm vibration? 8.2.28. 2.2 whole-body vibration?vibration? rn 8.38. 3 What is/are thethe source(s) ofof vibration?vibration? · ...... · ......

IINI 8.48. 4 For how long per day isis thethe workerworker exposedexposed toto vibration?vibration?

· ...... hours/day YES NO

IINI 88.5. 5 Is the vibration disturbing,disturbing , accordingaccording toto thethe worker?worker?

If yes, in what way?way? · ......

· ...... YES NO

8.6 Can the vibration source(s)source(s) bebe eliminated?eliminated?

If yes, how?how? · ...... · ...... - 181 --

YES NO

88.7. 7 Can thethe source(s)source{s) bebe isolated?isolated?

If yes, how?how?

IINI 8.8 Suggestions forfor improvementimprovement (related(related toto itemsitems 8.2-8.7)8.2-8.7)

9. DUST, SMOKE, GAS,GAS, CHEMICALS,CHEMICALS, ETC.ETC.

1I'D'10 1 9.19.1 Is the workerworker exposedexposed to:to: YES NO

9.1.1 Dust? source:

9.1.2 'Smoke?' Smoke? source:source......

9.1.3 Gas? source:source...... " .. " " ."

9.1.4 Chemicals? namely: ......

9.1.5 Other dangerous substances? namely.namely: ......

IIDI110 I 9.2 Is ventilation adequate?adequate?

1101¡ID! 9.3 If the worker is1S exposed to sawdust, is1S itit adequatelyadequately removed fromfrom thethe workplace?workplace?

IIN1IINI 9.4 If the worker is1S exposedexposed to gas,gas, doesdoes thethe worker~'iorker wear a mask? IINI 9.5 If the worker is1S exposed to chemicals,chemicals, doesdoes the worker wear protective clothing (gloves,(gloves, shoes,shoes, apron) or aa gas mask?mask? - 182182- -

IINI 9.69. 6 Is the worker suffering fromfrom anyany healthhealth problemsproblems re-re­ lated to sawdust, saw-vapour,saw~vapour, gas,gas, chemicalschemicals (i.e.(i.e. YES NO skin irritation,irritation, irritationirritation ofof thethe eyes,eyes, roughrough voice, eczema, asthma)?asthma)? ......

If yes, specify what.what : ......

IINI 9.79. 7 Suggestions for improvementimprovement (related(related toto itemsitems 9.2-9.6)9.2-9 . 6)

10. CLIMATIC FACTORSFACTORS

IINIIIN1 10.1 Is the worker exposedexposed to:to: YES NO

10.1.1 Cold?

1010.1.2. 1.2 Heat2Heat?

10.1.310.1.3 Humidity?

10.1.4 Draught? .

IINI 10.2 Suggestions for improvement

11. STRESS, MENTAL WORKLOAD YES NO

IINI 11.111 . 1 Is the work pace controlled byby thethe worker?worker? .....

If YES,YES , continue atat 11.211 . 2

If NO, is the pacepace controlledcontrolled by:by: YES NO

1111.1.1 . 1 .1 The machine thethe workerworker isis operating2operating?

11.1.2 Other machine(s) oror worker(s)worker(s) (after(after oror be-be­ fore the workerworker inin thethe productionproduction process)?process)?

11.1.311 . 1.3 Other factors

If yes, describe:describe: ...... • - 183 183 -

YES NO

IINI 11.2 Can the worker determine whenwhen to taketake short breaks? 11.3 Isls the job task very repetitive?repetitive? EB How frequently doesdoes thethe samesame workwork elementelement occuroccur during a 10-minute period?period?

YES NO 1101IIDI 11.4 Can the worker determine which tools, techniques and methods will bebe used?used?

11.511.5 Is the worker closely supervised?supervised?

1MI101 11.611.6 Does the job task imply social interactioninteraction or co- operationoperation with other people? . . ...

11.7 Is the worker isolated most of the working day (e(exceptxcept during longerlonger breaks)?breaks)?

If yesyes,, explain nature ofof isolation:isolation :

YES NO

IINIIIN I 11.8 Does the worker rotaterotate betweenbetween different tasks?tasks?

IINIIINI 11.9 Suggestions for improvement (related(related toto itemsitems 11.1.1-11.1 . 1- 1111.8) . 8) ......

12. WORKING TIMETIME

1212.1. 1 Does the workerworker work:work: YES NO 12.1.1 Only day-time (not(not beforebefore 6.006.00 a.m.a.m. andand notnot after 6.00 p.m.)?p.m . )?

12.1.2 Two-shift work?work?

12.1.312 . 1.3 Three-shift work?work?

12.1.4 Other scheduling of working hourshours (e.g.(e.g. whenwhen changing shifts)?shi fts)? ...... '--- - L ._ - 184 --

12.2 When does work:work:

start? ...... hours

finish? ...... hours

12.3 Work extends over:over:

how many days per week? days

how many months perper year?year? ...... months YES NO

IINI 12.4 Does the worker take (a)(a) meal break(s)?break(s)? .

If yes:

From to' ...... (hours)

From ...... to (hours)

Where isis the meal breakbreak taken?taken? YES NO

IINI 12.5 Does the worker take any other breaks?

IfIf yesyes;

How often?

How long each time? ...... minutes

Where are the breaks spent?spent?

IINI 1212.6. 6 Suggestions for improvementimprovement

13.13. GENERAL SAFETY AND HEALTH ASPECTS YES NO IINI 13.1 Has the worker experienced any accident(s)accident(s) onon the job?job? ......

If yes, give details: - 185185 --

YES NO IINI1INI 13.2 Does the worker recall fatalfatal accidentsaccidents oror accidentsaccidents

leading to loss of work among his fellow workers? .

If yes, give details: · ...... · ......

YESYES NO

IIN1IINI 13.3 Is the worker exposed to any obvious accident risk?risk?

If yes, which:which:

YES NO 13.4 Does the worker expose otherother personspersons toto accidentaccident risks? .

If yes, howhow andand which:which: · ......

YES NO

IINI111'41 13.5 Do safety regulations exist forfor thethe job?job?

If yes, are they adequate? ......

IINIIINj 13.6 Is adequate first-aid equipment available?

IITN'IN I 13.7 Has someone at the work sitesite beenbeen trainedtrained inin first aid? ..

IIINIINI 13.8 Does the worker suffer fromfrom healthhealth complaints?complaints? .

If yes, give details: - 186 -

YES NO IIN1IINI 13.9 Does the worker recallrecall thatthat fellowfellow workersworkers havehave givenglven upup employmentemployment because ofof healthhealth complaints?complaints?

If yes, givegive details:details:

YES NO

IINI¡IN 1 13.10 Is the workerworker exposedexposed toto anyany obviousobvious healthhealth risks?risks?

If yes, which:which:

YES NO

IINI 13.1113.11 Has the worker access toto adequateadequate medicalmedical care?.care?' .'. .

IINI1INI 13.1213.12 Comments and suggestions forfor improvementimprovement

14. PREMISES AND FACILITIESFACILITIES YES NO 14.1 Can thethe workerworker enterenter andand leaveleave thethe workplaceworkplace safelysafely and easily?

14.2 Are passagewayspassageways clearlyclearly markedmarked withwith warningwarnlng signs?signs? .

14.3 Are there sufficientsufficient auxiliaryauxi liary supports,supports, e.g.e.g. steps,steps, handles, railings?railings?

If yes, isis theirtheir designdesign andand placementplacement adequate?adequate?

14.4 Are cabins, platformsplatforms andand otherother constructionsconstructions safe?safe?

14.5 Is the working floorfloor freefree fromfrom obstructionsobstructions andand risk of slipping?sl ipping? ......

14.6 Is there sufficient workingworking spacespace toto movemove freelyfreely and safely?safely? ......

14.7 Are dangerous movingmoving partsparts ofof machinesmachines adequatelyadequately guarded? ...... - 187187 --

YES NO 14.8 Is fire equipment adequately locatedlocated andand inIn working order?order? ......

14.9 Are there adequate sanitary and hygienic facilities (toilets, washing facilities)? ......

14.10 Is adequate housekeeping providedprovided (proper(proper storage of tools, rawraw materialsmaterials andand products,products, cleaning,cleaning, disposal of waste, maintenance of premises and equipment)? ......

14.11 Are machinesmachines andand equipmentequipment regularlyregularly maintainedmaintained and inspected? ......

14.12 Are electricalelectrical installationsinstallations safesafe andand regularlyregularly maintained and inspected?inspected?

14.13 Other observations:observations:

IIN1IINI 14.12 Suggestions for improvement (related(related toto itemsitems 14.1-14.1- 14.13) ...... - 188188 --

15. PERSONAL PROTECTIVEPROTECTIVE EQUIPMENTEQUIPMENT

Not How often Not Not Not. Provi- Equipment Needed Used prOV1-pray).- 1Sis equipment needed used ded ded replaced?

15.1 Safety helmet

15.2 Ear pro- tectors

15.3 Eye pro- tectors

15.4 Safety gloves f------'--" -'- . ------15.5 Safety leggings r---.------~ .--.-- . -. ------" ------15.6 Safety boots I -----. ------f-- 15.7 Gas/dust mask .------15.8 Protective I clothing I I 15.9 Other per-per- , sonal pro-pro- tectitective ve equipment

Please ...... specify ......

YES NONO

IINIiIN I 15.10 lsIs the personalpersonal protectiveprotective equipmentequipment properlyproperly cleaned and maintained'maintained? ......

If yes, by whom'whom? ......

how often'often? ...... - 189189 --

IINI 15.11 SuggestionsSuggestions forfor improvementimprovement ofof personalpersonal protectiveprotective equipment ......

16. AID TOOLSTOOLS FORFOR SAFESAFE FELLING,FE LLING, DEBRANCH1NGDEBRANCHING ANDAND CROSS-CUTTINGCROSS-CUTTING OFOF TREESTREES

Not Not Not Aid tools Needed Used Provided Aid too I s ln~~~edneeded I Needed '~~:dused Used provided r------~------f------16.1 FelhngFelling leverslevers I I . type:type...... i I 1------t-: ------~ ------+-----+------1 16.2 Wedges I ! ! I f-_____type- ___ ._• . .:. .._ ._._ _ t_y_pe~ ..:~ _~._ j __. ____ j ______------I

1616.3. 3 Lifting devicesde~ ! I, (e.g. hooks,hooks, tongs)tongs) " i I ' type:type...... : ----~------,------t------4 ------1------

1

16.4 Aid tools for taking I 'I' ddownown hung-up treestrees i ,

type:type...... i ! ~------1--~--+--~-+---~-----1

16.516.5 Other aid toolstools ; i type:type- ...... i

IIN I 16.616.6 Suggestions for improvement of aida i d tools

...... ~ ...... - 190 -

17. SAFETY DEVICESDEVICES ONON CHAINCHAIN SAWSSAWS IIDI1101

Not Not Safety devicesdevices Available . Functioning available functioning

17.1 Front handlehandle guardguard

17.2 Rear handlehandle guardguard

17.3 Automatic chainchain brakebrake

17.4 Chain catchercatcher

17.5 ThrottleThrottl~ controlcontrol

1717.6 .6 Anti-vibration system (e.g.(e.g. damp-damp- ening elements)elements)

17.7 Spiked bumperbumper

17.17.8 B Guide bar cover

IINIIIN1 17.9 How is maintenance organised (schedule,(schedule, responsibilities,responsibilities, place)?

IINI'IN! 17.1017.10 SuggestionsSuggestions for improvement of chain saw safety

lB. INFORMATION ABOUTABOUT SOCIALSOCIAL SECURITY,SECURITY, WORKERS'WORKERS' WELFAREWELFARE ANDAND NUTRITIONNUTRITION

lB.l18.1 What isis compensation inin casecase ofof accident?accident?

18.2lB.2 What isis compensation inin case of sickness? ...... - 191 191 --

1818.3. 3 What is compensation inIn casecase ofof invalidity?invalidity?

18.4 What is compensation inin case of retirement?retirement?

1818.5. 5 How many days paidpaid annual leave isis thethe workerworker entitled to?

days

1818.6. 6 How many days maternity leave isIS thethe workerworker entitled to?t o ?

days YESYES NO

IINI 18.718.7 Is housing provided?

If so, what kind?kind?

YESYES NO

IINI 1818.8. 8 Is transportation to and from work provided?provided? . . ..

If so, how is it organised?

IINI 18.9 How far, and for how long,long, does thethe workerworker walkwalk dailydaily to and from the worksite?

YES NO 11NIIINI 18.10 Is adequate sheltershelter providedprovided atat thethe worksiteworksite (from(from rain, heat, wind)?wind)? ..

1818.11. 11 Are camping facilitiesfacilities provided?provided~

If yes, are theythey adequate?adequate?

IINI 1818.12. 12 What are the worker's mainmain activitiesactivities outsideoutside work?work? ......

IINI 18.13 When and wherewhere doesdoes thethe workerworker havehave hishis mainmain meals?meals? ...... - 192 --

IINIIIN I 18.1418.14 WhoWho prepares thethe food?food?

YES NO

18.15 Is any food providedprovided oror subsidisedsubsidised byby thethe employer?employer?

If so, what kindkind ofof food?food? ......

how much2much?

how often? ......

IINI 18.16 Does the worker eateat thethe followingfollowing foodfood itemsitems daily?daily? weekly?

Food item Daily Weekly

Rice, malze,maize, bread, cassava,cassava, potatoespotatoes or other carbohydrates

Fish, meat, eggs, dairydairy produce,produce, beansbeans

Vegetables, fruitfruit

IINI 18.17 What is the availability and quality of drinking water?

IINI 18.1818.18 SuggestionsSuggestions for improvement (related(related to itemsitems 18.1-18.1- 18.17) - 1_93193 -

19. WORKER'S BACKGROUNDBACKGROUND

19.1 Time workedworked withwith thethe enterprise.enterprise: ...... years

19.2 Time workedworked onon presentpresent job.job: ...... yearsye ars

19.3 Type ofof employmentemployment (permanent,(permanent, seasonal,seasonal, casual)casual) ......

OA'IINI 19.4 Education:

19.419.4.1. 1 How many years has the worker spentspent inin school?

years YES NO 19.4.2 Can he/shehe /she readread andand write?write" ...... TA 19.5 Training: YES NO IINIlIN I 19.5.119.5 .1 Was initialinitial instructioninstruction providedprovided whenwhen thethe worker started on hishis/her iher job?job? . [__"'''''-J .J1 .. __ If yes, please describe

YES NO _.. _---- 19.5.219.5.2 Are instructioninstruction manuals necessary?necessary? ... ..

If yes, are they available and understoodunderstood byby the ' worker?worker? ......

IINII1N1 19.519.5.3. 3 Has the workerworker receivedreceived basicbasic trainingtraining forfor the job?job? ......

If yes, please describe

YES NO IINIIINI 19.5.419.5.4 Has the worker practical experience/training Inin other jobs?jobs? ......

If yes, which ones? -- 194194 --

19.6 How are wages paid:paid: YES NO

19.6.1 Based on time2time?

19.6.2 Based onon task.?task?

19.6.3 Piece rate2rate?

19.6.4 Based on time plus productionproduction bonus'bonus?

IINI 1919.7. 7 Trade union:Unlon: YES NO 19.7.1 Is the worker a member of aa tradetrade unionUnlon oror a workers' association?association?

If yes, whichwhich one?one? ...... YES NO 19.7.2 Has the tradetrade unionunlon negotiatednegotiated aa collectivecollective

agreement withwith thethe worker'sworker's employer?employer? . . .

IINI 19.819.8 Suggestions made by thethe workerworker forfor anyany kindkind ofof improvements

IINI11NI 1919.9. 9 What does the workerworker likelike bestbest aboutabout thethe job?job?

IIN1IINI 19.10 What does the workerworker likelike leastleast aboutabout thethe job?job?

19.11 Comments - 195195 --

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