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SlCK BUILDINGi·SYNDROME; A REVIEW - by J M Sy;kes, BSc, CEng, MIOH, Principal Specialist Inspector JlllC .. SICK BUILDING SYNDROME: A REVIEW by J K SYKES BSc. CEng. KIOH SUMMARY This paper reviews published information on 'sick building syndrome•·, the cause of reputedly high incidence of sickness amongst occupants of sealed, mechanically ventilated buiidings. It discusses symptoms, common features of 'sick buildings' and possible causes. On the basis of reported cases, there appears to be no single cause but a series of contributing factors. ; ; ; CONTENTS PAGE Introduction 1 Definition 1 Reported Cases 1 Symptoms and Prevalence 1 Common Features of Sick Buildings 2 Possible Causes 2 Airborne Pollutants 3 Effects of Airborne Contaminants 5 Odours 6 Charged Air Ions 6 Inadequate Ventilation 6 Relative Humidity 7 Working Environment, Comfort and Sensory Perception 8 Lighting 9 Visual Display Units (VDUs) 9 Dis-satisfaction and psychological Causes 9 Conclusion 10 References 11 APPENDICES APPENDIX NO TITLE PAGE 1 Investigation and Research Reports on Building Sickness 17 2 Table 1 Air Contaminants Detected in Tight Building/Investigations 18 Table 2 Gases Found in Cigarette Smoke 19 Table 3 Physical Irritation Caused by Smokers 20 iv INTRODUCTION REPORTED CASES Concern about the reportedly high incidence of Reports of 'sick bu i 1ding syndrome' fa 11 into two sickness amongst people who work in sealed categories - investigation of cases in order to buildings, especially offices, has attracted prescribe a remedy, and surveys of office and other considerable attention. In the UK this is a bu i 1dings to assess the extent of the prob 1em and comparatively recent problem, most reports having its likely causes. Many in the latter category been published since 1980, but in other countries, usefully include 'sick' and 'control' buildings to especially in North America and Scandinavia, the enable comparison. Appendix 1 lists the reports prob 1em was first reported so111e 30 years ago, both considered and possible causes. in the workplace and the home. One noteable shortcomi~g is that few investigations Various terms have been used to describe the are completely multidisciplinary in approach so that phenomenon 'building sickness', 'sick building papers often consider separately the medical syndrome', 'sick office syndrome', 'tight bu i 1ding aspects, measurement of airborne contaminants or an syndrome', 'office eye syndro111e' and others. None assessment of the physical environment and the adequately describe the condition but the term 'sick ventilation or air conditioning system. Few bu i 1ding syndrome' has been accorded recognition by s i mu 1taneous ly study a 11 three aspects of the the World Health Organisation (WH0) 1 and is the most prob 1em. This means that some investigations have widely used. drawn conclusions which do not appear to be fully supported by the reported facts, possibly because 'Sick building syndrome' continues to attract both not all of the information found in the speculation and controversy and, unfortunately, many investigation is reported or possibly because the of the plethora of papers on the subject are devoted investigators have made assumptions. Whatever the more to speculation than to fact. Its nature, reason, some conjecture appears to be subsequently prevalence, causes and even its existence are open reported as fact, especially in the press. to debate. This paper reviews current published Unfortunately, few investigations have conclusively information on the subject. proven a cause by the successful application of remedial measures in a controlled sequence. DEFINITION In addition to case investigation and studies, a 'Sick building syndrome' is, by its nature, ill number of papers consider a particular, narrow defined. One definition used is "a building in aspect of 'sick building syndrome' or one postulated which complaints of ill health are more common than cause. Some provide a usefu 1 and deta i 1ed insight 3 might reasonab 1y be expected" , This has some into that aspect wh i 1st in others it appears that drawbacks since it does not address the question of the particular author has used 'sick building whether such complaints are, or are not, justified. syndrome' as an excuse, rather than a reason, for However, the common feature of sick buildings is the work. that their occupants suffer, or appear to suffer, a measurably higher incidence of illness than expected SYMPTOMS AND PREVALENCE for no readily identifiable reason. Clinically diagnosed illnesses which can be readily attributed Most reports of outbreaks deta i 1 a common 1 is t of to a particular cause such as humidifier fever, symptoms. These are summarised by WH0 1 as: Legionnaires disease or to ellposure to a toxic agent in the environment are not usually regarded as 'sick - eye nose and throat irritation building syndrome'. - sensation of dry mucous membranes and skin - erythema (skin rash) Various authorities and authors have attempted to - mental fatigue subdivide 'sick building syndrome' into different - headaches, high frequency of airway infections 1 categories. Most notably, WH0 , differentiates and cough between 'temporarily sick buildings' where symptoms - hoarseness, wheezing, itching and unspecified decrease and disappear in time and 'permanently sick hypersensitivity bu i 1dings' where they persist, often despite the - nausea, dizziness. most extensive remedial measures. Some researchers and authors have postu 1ated sub species of 'sick Some investigations have produced more extensive building syndrome' based on their particular area of lists of symptoms including, for example, high blood 4 5 6 7 interest , • Such an approach may have advantages if pressure and miscarriages • However, these are the different symptoms suffered by the occupants of mentioned as occurring amongst staff in sick sick bu i 1dings can be shown to have many different buildings; they are not specifically attributed to causes. 'sick building syndrome'. The range of symptoms and their prevalence may to be assumed that they are relatively mild. depend, to some extent, on the questionnaire used. However, reports on its prevalence suggests that the Investigation of symptoms is often carried out by a to ta 1 number of sufferers is great and despite the self administered questionnaire and the response inconclusive results from performance tests, some may , in some cases, be influenced by the number and reduction in personal performance and motivation nature of the questions. cannot be ruled out. Studies in the UK 3 8 9 41 42 show a number of eot9«JN FEATURES Of SICK BUILDINGS patterns: The WH0 1 identifies a number of features common to (a} Symptoms are most com111on in air conditioned sick buildings. Summarised, these are: buildings but they also occur in buildings that are naturally ventilated. (a) They often have forced vent i 1at ion (WHO does not make specific reference to air conditioning (b} Clerical staff are more likely than managerial although air conditioning will fall into this staff to suffer, and complaints are more frequent in general category). the public than the private sector. Complaints are also more frequent in offices housing many staff. (b) They are often of light construction . ( c) People with most symptoms have 1east perceived ( c) Indoor surf aces are often covered in text i 1es control over their environment. (carpets, furnishing fabrics etc}. ( d} Symptoms are more frequent in the afternoon ( d} They are energy efficient, kept re 1at i ve 1y warm than the morning. and have a homogeneous thermal environment. Some investigators have sought to show a link (e) They are airtight, ie windows etc cannot be between 'sick building syndrome' and performance/ opened. neurological tests. Sterling and Sterl ing 10 used 'tremor' tests and 'T crossing' tests but failed to Subsequent comparative stud ies in the UK have tended 38 9 41 42 show a difference between the test and control to confirm these common features , , , although groups. Bergund 11 tested volunteers in 'sick' and sick building syndrome does not occur in all study buildings for stress, memory, vigilance, buildings with these features Wilson and Hedge 9 in reaction time and steadiness, again without finding their survey of 46 buildings in the UK, considered adverse effects. Although various papers have the building environment and air conditioning system discussed the effects of exposure to toxic design in relation to the prevalence of symptoms and 12 substances on behaviour , u and 11ental fatigue is found significant differences even amongst buildings one of the symptoms of sick building syndrome, those conforming to the WHO list of features. In general, studies by Sterling and Ster! ing and by Berglund cheaply constructed buildings with poorer air failed to show a measurable link between sick conditioning systems, especially pub I ic sector building syndrome and performance. One major survey buildings constructed in the 1970s, showed more does suggest a reduction in efficiency of 20% problems than well constructed buildings with more amongst occupants of sick buildings, but this is expensive air conditioning systems dating from the based on personal opinions of those showing symptoms 1980s. The type of glazing al so appeared to be rather than on performance measurements. significant - all of the least healthy buildings, but none of the healthier buildings, had tinted The prevalence and overall effect of 'sick building glazing. syndrome' are difficult to assess since most