Volume 16 Number 2, Dec 2017 Environmental and Occupational Health Impact of Mining in : A Review

Lee KYa, Ho LYa, Tan KHa, Tham YYa, Ling SPa, Qureshi AMa, Ponnudurai Ta, Nordin Ra aJeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia

ABSTRACT

In the perspective of recent bauxite mining in Malaysia, this review aims to identify the potential environmental and health impacts on miners and surrounding communities. The environmental issues of bauxite mining include, air, water and soil pollution due to bauxite dust; leaching of bauxite into water sources resulting in reduced soil fertility as well as affecting agricultural food products and aquatic life. Bauxite occupational exposure affects the health of miners, and has negative consequences on the health of surrounding communities, such as increased respiratory symptoms, contamination of drinking water, other potential health risks from ingestion of bauxite and heavy metals, including noise-induced hearing loss and mental stress. This review discusses the processes of bauxite mining, its constituents and residual trace elements, and their impact on the environment and health of exposed workers and communities. It also explores the Malaysian legal requirements and standards of occupational exposure to bauxite.

Keywords: Bauxite mining, occupational and environmental health impact, Malaysia

INTRODUCTION

4 Aluminium (Al) is the most plentiful metal in and diaspore [α-AlO(OH)] . In addition, other earth’s crust, representing more than 7% by weight, compounds are also found in bauxite such as and is the third most abundant element after silicon hematite [Fe2O3], goethite [FeO(OH)], quartz [SiO2], 1 and oxygen . Because aluminium is highly reactive, rutile/anatase [TiO2], kaolinite [Al2Si2O5(OH)4] with 4 it is mostly found in oxidised form, of which impurities in traces . Trace elements found in approximately 250 different minerals exist1. Due to bauxite include arsenic, beryllium, cadmium, high chemical reactivity, aluminium is never found chromium, lead, manganese, mercury, nickel and in the elemental state1. In terms of production, naturally-occurring radioactive materials such as 2 bauxite is the main source of the world’s aluminium, uranium and thorium . These elements often remain supplying 99% of metallic aluminium1,2. Many attached to the bauxite residue even after alumina 2 minerals including feldspars contains aluminium, but extraction . extraction from these is expensive and requires high energy compared to bauxite3. Bauxite is formed as a weathering product of 1, 4 low iron and silica bedrock . The weathering Bauxite was first discovered near the town of Les process involves the exposure of various igneous, Baux in France, and was named after that town. It is sedimentary, and metamorphic rocks to the tropical 2 the principal ore of alumina (Al2O3) which is an and subtropical climates for millions of years . immediate precursor in aluminium production2. Ninety per cent of bauxite resources in the world Having reddish-brown colour, bauxite is a naturally can be found in tropical areas while the rest in occurring heterogeneous material and composes of other latitudes have been exposed to prolonged 2 one or more aluminium hydroxide minerals, weathering in their geological past . Large bauxite principally gibbsite [Al(OH)3], boehmite [γ-AlO(OH)] reserves are found in Central and South America particularly in Brazil, Guinea and Australia2, 4. In Malaysia, bauxite resources are mainly located in Bukit Batu, Bukit Gebong, Lundu-Sematan, and Tanjung Seberang in , Bukit Mengkabau and Corresponding author: Labuk Valley in , Sungai Rengit and Teluk Prof Dr Rusli Bin Nordin Ramunia in , and Bukit Goh in , Jeffrey Cheah School of Medicine and Health Pahang5. Sciences Monash University Malaysia Bauxite can be extracted from the surface or No. 8, Jalan Masjid Abu Bakar underground deposits. Most bauxite occurs near the 80100 Johor Bahru, Johor, Malaysia surface of earth with 1 or 2 meters of overburden Email: [email protected] consisting of top soil and vegetation2. In addition, Tel: +6072190629 Fax: +6072243311

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underground deposits occur due to covering of meters thick under an overburden of up to 10 other materials over bauxite after it has been meters thickness6. The deposits vary in thickness formed, and require underground mining to extract and most can be mined and processed without these deposits economically2,4. Surface mining is further treatment to concentrate the mineral more often carried out compared to underground through process of beneficiation. However, bauxite mining because most of bauxite deposits occur close ore from northern Brazil and Vietnam has a to the surface. Bauxite is thus extracted by shallow, high clay content, and has to be washed before open-cut mining using open-pit method from large processing3. Underground deposits require blanket-type lateritic deposits, which are 4–6 underground mining to extract them economically.

Figure 1: Typical processes involved in surface mining of bauxite deposits3

Bauxite ore is then refined into alumina (Al2O3) by economically viable reserves of aluminium to last 1 Bayer process, where these aluminium-containing another 100 years to supply for current demand . minerals are dissolved in hot sodium hydroxide There is a growing need for bauxite due to (NaOH)6. The insoluble solids (bauxite residue, mud increasing demand for quality aluminium products, and ) are washed, or partially neutralized and new reserves are to be discovered for economic 1 (using CO2 or seawater treatment), and deposited in viability . impoundments around the refinery using wet (yielding 15–30% solids) or dry (with 50–65% solids) Other than bauxite, alternative sources of disposal techniques6. Most of alumina then aluminium include kaolin clay, oil shale, coal 6 undergoes the Hall-Heroult electrolytic process to wastes and mineral anorthosite . However, bauxite be transformed into aluminium. reserves are plentiful and economically cheap compared to these alternatives; therefore, Approximately two to three tonnes of bauxite are technologies to process alternatives into aluminium required to produce a tonne of alumina as bauxite are not expected to progress beyond the 4 only contains 30-54% alumina1. Four to six tonnes of experimental stage . bauxite are required to be purified to produce one tonne of aluminium metal. Compared to refining of Recently, there appears to be concerns about the bauxite and electrolytic reduction of alumina, impact of bauxite mining not only towards the bauxite mining consumes only a small amount of environment, but also on the health of population, energy. especially in Kuantan. Mining areas are situated within residential zones, which lead to worries Current, global bauxite resources has been among the general public of its effects. estimated at more than 70 billion tonnes, with Environmental pollution due to bauxite mining the largest concentration in Guinea, where an remains a concern not only because of direct estimated 25 billion tonnes of bauxite might be pollution, but also due to detrimental short and long present3. It is projected that there are sufficient term effects. However, there is a lack of studies

138 Volume 16 Number 2, Dec 2017 especially in Malaysia on this matter, justifying the When it came to obtaining literature for the review, need for a review to allow better understanding of relevant research concerning environmental and its impacts, the standards of exposure and the laws occupational health impact of bauxite mining was pertaining to bauxite mining. identified by searching on Ovid Medline and PubMed. In order to ensure that relevant studies This paper aims to provide a general review of the were not missed, the search terms remained broad. impact of bauxite mining and its contents on the environment and individuals’ health, and to Using PubMed, keywords such as “bauxite”, “health encourage detailed research in this area. impact”, “aluminium oxide”, “bauxite refining”, “bauxite mining respiratory”, “bauxite mining MATERIALS AND METHODS occupational” were searched.

Search strategy The bulk of the research was done on Ovid Medline First of all, Google Scholar search and BMJ were because of its extensive library of research papers used to better understand bauxite mining and its that allows a comprehensive search using the effects. Cochrane library was then used for further Medical Subject Headings (MeSH) and “Additional research as it provided higher quality articles. On Limits”. No language restrictions were employed, st Google scholar, the keywords used were “bauxite and any paper published until 31 August 2016 was Malaysia review”, and the limit was set to “where reviewed. The following shows the relevant my words occur”. keywords used to narrow down our search:

Topic Keywords Accidents Accidents, Occupational Adverse effects Adverse effects Air pollutants Air pollutants, Air, Pollutant, Occupational, Analysis, Adverse effects Bauxite Aluminium oxide, Aluminium, Oxide, Bauxite

Bauxite mining Aluminium oxide, Aluminium, Oxide, Bauxite, Mining Dust Analysis Dust, Analysis Forced expiratory volume Forced expiratory volume, Forced, Expiratory, Volume Heavy metals Heavy, Metals, Heavy metals Health Impact Health, Impact, Health impact Inhalation exposure Inhalation, Exposure, Inhalation exposure Metallurgy Metallurgy Noise Noise, Occupational, Adverse effects Occupational exposure Occupational, Exposure, Occupational expo- sure, Adverse effects, Occupational diseases, Mortality, Analysis Occupational health Occupational, Health, Occupational health Risk assessment Risk, Assessment, Risk assessment

Selection criteria mainly on the extraction process and neutralization of bauxite or social issues pertaining to the mining. The next step was a detailed examination of papers, and at this point, studies were chosen On the other hand, studies that were done in based on relevant type of ores mined and refined. different areas such as Western Australia, India, For instance, “kaolinite”, “vermiculite mining”, Mozambique, Surinam and others, were included due “asbestos” and “aluminium nanoparticles” were to the lack of studies done in Malaysia. Also, articles excluded from the list. Other than that, articles were selected based on its context of bauxite mining that were excluded include formal documentation impacting on the environment, which includes study such as proceedings of a meeting, report of policy of microbial life, plant growth and soil content after strategies, new sites for mining, studies focusing mining.

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An illustration for our selection criteria is as follows:

668 articles 305 articles (focusing 670 articles (2 incomplete mainly on environmental, extracted articles were health and occupational excluded) impact) were included

Only 50 articles (focusing mainly on environmental, health and occupational impact) were selected due to journal requirement on article limit

RESULTS

Based on our research, Australia is the world’s bauxite sector saw a dramatic increase in largest producer of bauxite (80,000 tons), production from year 2014 to 2015, with 6.5 times representing 29% of global production in 20157. This increase, from 3,260 tons in 2014 to 21,200 tons in is followed by China (60,000 tons, 22%) and Brazil 2015. This was due to strong demand from China (35,000 tons, 13%). These facts are reflected in after Indonesia banned its exports to encourage Figure 1. It is pertinent to note that Malaysia’s domestic processing.

Figure 1: Amount of bauxite produced by country in 2014 and 20157.

140 Volume 16 Number 2, Dec 2017 In terms of bauxite reserves, the largest Indonesia (1,000,000 tons)7. As can be seen in concentration of bauxite reserves is located in Figure 2, compared to other bauxite-rich countries, Guinea (7,400,000 tons), followed by Australia Malaysia only has an estimated 40,000 tonnes of (6,200,000 tons), Brazil (2,600,000 tons), Vietnam bauxite reserves. (2,100,000 tons), Jamaica (2,000,000 tons) and

Figure 2: Bauxite reserves by country in 20157.

Impact Of Bauxite Contents And Bauxite Mining On The Environment

Bauxite mining has a direct impact on the open-pit drilling and blasting, loading and haulage, environment by polluting air, water sources and soil vehicular movement, ore and waste rock handling (Table 1). The environmental pollution exerts generate dust particles3. indirect effects on the health of miners and nearby communities. In general, these particles can be classified into coarse and fine particles, where coarse particles Air Pollution have a 1-10 μm range while fine particles have a 0.1 -1 μm range9. Coarse particles commonly originate One of the primary concerns of bauxite is the from erosion, road and soil dust dispersion by wind, release of airborne particulate matter due to as well as anthropogenic activities such as vehicle mining activities. According to the International emissions9. The coarse particles are of lesser Standardization Organization (ISO) and British concern as studies have shown that they tend to Standard Institute, dust is defined as ‘small solid deposit in larger airways, hence can be coughed out. particles, usually below 75 μm in diameter, that Fine particles, on the other hand, which are also settles under their own weight but remain produced during bauxite mining, can be lodged deep suspended for some time’8. In bauxite mining, within alveoli, potentially leading to respiratory and activities such as site clearance and road building, cardiovascular problems8, 10.

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Table 1: Types of environmental pollution in bauxite mining Air pollution Dust emissions (large particles ranging 1-10 µm, fine Gelencser A KN particles ranging 0.1-1µm) leading to cardiovascular and et.al respiratory problems Reduced FEV1 after dust exposure (≥100mg/m3) of 20 years Donogue AM among non-smokers et.al. Water pollution Leaching of iron, aluminium, arsenic, cadmium, lead, Petavratzi E KS nickel, manganese and mercury into drinking water sources et.al High concentration of heavy metals in sediments, which are Yi YJ et.al. deposited in the water, further dissolves and deposits into fish and benthic invertebrates, in which levels are 10-1000 higher than in normal water. Soil pollution Soil contamination of heavy metals decrease microbial Raymond AW activities which lowers its fertility FE et.al. Low levels of carbon, nitrogen, phosphorus, potassium, Lad RJ et.al. calcium and magnesium in post-mining soil in India Insufficient soil depth for agriculture (<15cm) Coke LB WC et.al. Habitat destruction and soil erosion Mertzanis A et.al Food Lead, cadmium, arsenic accumulation in vegetables Zhou H et.al. contamination High levels of lead found in sweet potato, exceeding CODEX Wright V JS safety limit of 0.1mg/kg et.al.

Dust can react with the air in atmosphere, causing Impact on Water Sources various chemical reactions, affecting soil, hence health of plants; meteorological and local climate, Most of the surface water in the world consists of as well as penetrating into vegetation depending on streams, rivers, springs, ponds and lakes. These particle size8. Dust can also dissolve in water, and water sources closely interact with soil and rocks on flows down the food chain, where it is ingested by the aforementioned surface, temperature and pH of humans, or aquatic animals8. environment, influencing adsorption and desorption 12 of inorganic and organic matters . Bauxite dust is visible due to high iron oxide content, having red colour which contaminates Water contamination by bauxite mining activities, clothes, properties, vegetation, food and water especially drinking water sources, has the potential sources11. It is classified for occupational hygiene to cause harm due to components such as iron and purposes as a ‘nuisance dust’ (coarse particles aluminium as well as other toxic heavy metals found that decrease environmental amenity, damages in trace amounts (arsenic, cadmium, lead, nickel, 8 machinery, decreases visibility, or acts as an irritant manganese and mercury) . This is especially true for substance) or a “particle not otherwise specified”3, heavy mining activities which have been aggressively 8. Bauxite dust is detrimental because it can carried out. decrease visibility and result in visual changes to the environment8. It can be deposited into machineries, The most significant impact of heavy metals on the reducing their life cycle and overall productivity8. river is on sediments, aquatic organisms, and the water itself. Heavy metals do not degrade, Bauxite dust is inhalable (respirable), and defined depositing in sediments to be taken up by plants, 13 as dust particles less than 10µm in diameter or animals or by feeding benthic animals . According 10 particulate matter of PM10 and PM2.5 . In Kuantan, to a Chinese study conducted on a river exposed to 3 24-hour PM10 level ranged from 167-277 µg/m mining, concentrations of heavy metals in sediments during December 2015, which exceeds Malaysian were 1000-100,000 times greater than water whereas National Ambient Air Quality Standard-201510. There concentration was 10-1000 times higher in fish and 13 is ‘no safe level’ for PM10 and PM2.5 as per the World benthic invertebrates . Fishes come into contact Health Organization, because these particles can with heavy metals through water, via breathing and 13 deposit in the alveoli during respiration and cause food chain . Heavy metals are mobilized in water, increased hospital admissions due to respiratory and are flushed downstream and deposited into clay cardiovascular problems8,10. Apart from damage to minerals, or absorbed by algae at the lower trophic 12 lungs, nose and throat, the eyes and exposed skin levels of food chain . As heavy metals accumulate, are at risk, as well as gastrointestinal tract8. In this leads to critical levels, causing more problems some, it can also cause allergic reactions such as by affecting organisms at higher food chains. asthma or eczema8.

142 Volume 16 Number 2, Dec 2017 Production of acidic water from mining activities support a limited number of crops16. Studies have can increase solubility of heavy metals and harm the shown that vegetable crops, root crops and legumes aquatic ecosystems, especially at pH 5 and below12. require a minimum of 30cm, which is lacking in Heavy metals can be introduced to groundwater by reclaimed land16. agricultural and industrial activities, mining, and land filling, impacting drinking water and irrigation In addition, open cast bauxite mining creates sources12. As heavy metals leach into soil and water, artificial pits with large volume of calcareous they can be released into air by surface erosion12. debris; this destabilizes the environmental balance by changing the geo-morphological processes17. In Kuantan, the river water near bauxite mining Land clearing processes before mining, such as sites is the essential source for surrounding deforestation, forest fires, opening up new road communities and there are several treatment networks for better access and waste disposal, lead plants located nearby10. Pollution of rivers by to habitat destruction and soil erosion. This can bauxite processing plants have resulted in closure of further result in loss of bio-diversity, water treatment plants11. Water samples taken from pollution and increased turbidity17. These effects nearby residences have exceeded the Health can be short-term, requiring a sizeable amount of Ministry’s aluminium levels of 0.20mg/L while time and resources to restore or can be severe to mercury levels were 0.0093mg/L, nine times above become irreversible17. the recommended level for raw water. However, continuous drinking water monitoring by Impact of Bauxite-contaminated Soil on Food State Health Department has reported that the Products concentration of aluminium and iron in drinking water has yet to exceed the National Drinking Water Bauxite-contaminated soil can be detrimental to Quality Standard11. health, as its contents can contaminate soil and water sources used in agriculture. Food products has Impact on Soil been identified as a major pathway for human exposure to heavy metals compared with inhalation Soil is one of the most important elements in the of soil particles, skin contact and drinking water18. ecosystem as it provides nutrients for the plants and Heavy metals can easily be taken up by vegetable is also the major site of degradation and roots and get accumulated at high levels in edible transference of biomass. Soil can form solid phase parts, although vegetable species differ in their where it comprises mostly minerals and organic ability to take up and concentrate heavy metals18. matters; or fluid phase when it interacts with Heavy metals that can accumulate in plant products water12. All of these phases involve ions interacting include lead, cadmium and arsenic. and entering the soil system. The excessive presence of heavy metals in soil is detrimental, as it For instance, cadmium in soil can be mobilized and inhibits such processes and biodegradation of readily absorbed by plants and crops. This was seen organic contaminants14. In addition, higher soil in a Jamaican study, where crops from previous contaminants lower its fertility. This can impact bauxite mining site contained high level of agricultural activity and decreases food quality and cadmium19. Cadmium not only accumulates in ultimately causing food shortages14. plants, but also leaches into water supply and sources where it gets deposited in aquatic animals, The quality of soil is determined by the presence of which are later consumed by the community19. organic carbon15. In a study conducted on Indian Chronic consumption of cadmium causes kidney and bauxite mines, mining soil showed low levels of bone damage, cancer, low birth weight and carbon along with low nitrogen, phosphorus, spontaneous abortion19. Thus concerns should be potassium, calcium and magnesium, which are raised regarding reclaimed bauxite mining sites for essential for healthy plant growth15. Moreover, soil agricultural purposes. in bauxite mines have high levels of Al (as bauxite ore is essentially Al2O3, Fe2O3 and SiO2), limiting the Other issues include leaching of heavy metals into growth of microbes in soil15. Without microbiological soil. Heavy metals can accumulate in crops. Among activity, nutrients are not released into soil, different crops planted in various locations, sweet restricting plant growth in acidic soil. This prevents potatoes showed the highest lead concentration, post-mining biological land reclamation15. However, which is beyond the safety level of 0.1mg/kg if there is contact of limestone and soil due to indicated by CODEX19. Lead poisoning is lethal, bauxite refining process, the reclaimed soil will be causes neurological disorders, as well as debilitating alkaline instead16. reproductive disorders and diminished intelligence after ingestion in children or newborns19. Comparing reclaimed and un-mined bauxite lands, it is found that the major difference between the two is the depth of soil16. Un-mined lands have deeper soil, which supports deep-rooted trees and agricultural crops; while reclaimed soil has approximate depth of 15cm or less and can only

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Figure 3: Various impacts of bauxite mining on the environment and on health3, 11

OCCUPATIONAL EXPOSURE TO BAUXITE MINING increased incidence of melanoma among miners but it was not significant24. Another research noted that Physical Hazards outdoor work does not increase the risk of Physical hazards encountered in bauxite mining melanoma3. However, heat and humidity result in include noise, heat, humidity, and ergonomic heat-related illnesses, which include heat problems such as vibration, ultraviolet radiation and exhaustion and miliaria rubra3. radioactive materials3, 20. Both studies acknowledge the potential for traumatic injury and elaborate that A few studies have noted radiation potential of injury in bauxite mining is uncommon compared to bauxite, since it contains small amounts of coal or metalliferous mining3. radioactive materials such as uranium, thorium and potassium3. One study in Mozambique found very Noise in bauxite mining originates from mining low radiation dose which was below the detection equipment and processes such as blasting, drilling, limits and radiation exposure risk25. Another study excavating and crushing3. Noise levels range from from Western Australia indicates that personal dose 85dB to 106 dB, and a study shows that this noisy levels across a range of jobs were below the public environment within 10m is potentially detrimental exposure limits of 1.0 mSv per year3. While to health3, 20, 21. Furthermore, most miners have high continued monitoring is necessary, radioactivity exposure as mines are being operated round the does not significantly impact on the human health3. clock3, 20, 21. This exceeds the healthy noise levels range (less than 85dB) and acceptable duration of Chemical Hazards exposure (101-106 dB for 4-15 minutes)22. Hence, There are a few related chemical hazards because noise-induced hearing loss is an important bauxite is biologically inert and is classified as a occupational hazard due to bauxite mining3. nuisance dust or ‘particle not otherwise specified’ in the context of occupational hygiene. However, A study in India concluded that vibration dose to an increased respiratory symptoms, such as cough, individual depend on work circumstances and type wheeze and rhinitis, have been noted among of machineries used23. Whole-body vibration is a bauxite miners, with self-reported symptoms hazard in bauxite mining but not the hand-arm ranging from 1.5% to 11.8%3, 26, 27. This is attributed vibration due to machineries used such as to bauxite dust from breaking-blasting the crust and excavators, drilling rigs, scrapers and haulage excavation, and loading of ore onto trucks. A study trucks3. The effects of whole-body vibration on of bauxite miners (exposed to bauxite and silica) miners can be reduced with proper maintenance of have shown non-specific airway responses, such as machineries. cough, mucous production and decreased forced 26 expiratory volume in 1 second (FEV1) . Another As bauxite mining is concentrated in tropical study showed a significant decline in FEV1 of 7.3mL/ climates, ultraviolet radiation exposures can year which was associated with employment contribute to skin cancers3, 24. One study noted an duration27. This association between employment

144 Volume 16 Number 2, Dec 2017 duration and FEV1 was independent of bauxite associated with air, water, and soil pollution due to exposure. Other studies have shown that cumulative mining activities11. exposure to bauxite was not linked to significant respiratory symptoms or lung function changes27, 28. Impact on Health due to Dust Particulate A study has described how large particles released A case of pulmonary fibrosis was reported after into the environment from open mining processes prolonged exposure to bauxite crushing and contaminate property, water, food sources and transport, and bauxite was found within fibrotic clothes and affect personal comfort. These nuisance area during autopsy29. However, recent bauxite particles cause irritation of eyes, nose and throat31. exposure studies in well-run facilities noted that These particles deposit on vegetation, making it bauxite is not associated with pneumoconiosis3, 30. unpalatable for human and livestock consumption11. Fine bauxite particles of PM10 and PM2.5 size Cancer Incidence and Mortality penetrate deep into the respiratory system and A study among Australian bauxite and alumina have been associated with increased hospital workers in relation to mortality and cancer rates admissions for cardiovascular and respiratory showed little evidence of increased all-cause diseases as well as premature deaths31. This is of cancers or combined cancer mortality24. Several great concern in the paediatric groups because of studies support this, and noted that there is no relatively smaller lung size compared to adults, increased risk of squamous and basal cell carcinoma whilst receiving a higher dose of particles32. In despite ultraviolet exposure; an increased risk of Kuantan, there was an increasing trend of asthma melanoma and pleural mesothelioma reported in and upper respiratory infections during 2015, one Australian study was unrelated to environmental compared to previous years. According to local or occupational conditions of aluminium industries3, health clinic data, this has been linked to the higher 24 3 . Instead, Friesen et al. observed that bauxite 24-hour PM10 levels ranging from 164 to 277μg/m exposure may be associated with an increased risk during the same time period, exceeding the of death due to non-malignant respiratory Malaysian National Ambient Air Quality Standards diseases30. 201511.

Biological Risks Impact on Health due to Contamination by Bauxite Important biological risks include communicable and Heavy Metals diseases such as dengue and malaria; hence, Water contamination by bauxite mining, especially appropriate chemoprophylaxis and vector control is drinking water, has potential for harm due to long- required3. Other community-acquired infections term ingestion of aluminium hydroxide, iron oxide such as human immunodeficiency virus (HIV) and and heavy metals11. Aluminium is a neuro-toxin and tuberculosis may affect the employees3. Therefore, has been linked to Alzheimer disease, though there mining companies should invest in education, is insufficient evidence on causation; while in screening, early diagnosis and treatment as well as children, high levels of aluminium exposure has providing travel medicine consultation to their been associated with bone disease due to reduced employees3. phosphate absorption11, 33. Meanwhile, iron oxide in bauxite can potentially cause iron overload upon Ergonomic Risks chronic ingestion, leading to gastrointestinal Bauxite mining has become highly mechanized, symptoms, hepatic disease, cardio-myopathies, hardly requiring manual handling, hence ergonomic diabetes, joint and skin involvement in the form of hazards are minimized3. Since mines operate hyper-pigmentation34. nonstop, fatigue has become a concern due to long shifts and overtime. Measures that have been put Chronic exposure to toxic metals causes multiple into place include fatigue risk management and organ toxicity and increases risk of malignancies11, monitoring. Addressing staffing issues and ensuring 35-37. Heavy metals can accumulate in food sources appropriate rosters help in reducing fatigue. and drinking water, eventually affecting the entire food chain. These show up in seafood and are IMPACT ON THE HEALTH OF SURROUNDING ingested by humans in high concentrations. These COMMUNITIES heavy metals include lead, arsenic, mercury, There are not many papers that discuss the impact cadmium, chromium, manganese and nickel, and of bauxite mining on surrounding communities, can result in central and peripheral nervous system because most mining sites are located in remote damage, impaired neuro-cognitive function, areas with well-defined boundaries. Only one paper nephrotoxicity, hypertension, cardiovascular by Abdullah et al. discusses this impact, by further disease, dermatological manifestations and dividing it into acute and chronic impacts11. Acute increased mortality35-44. In children, heavy metal impact is associated with short-term dust exposure, toxicity is associated with increased risk of death road accidents and vector-borne diseases. Mental from all causes, neuro-developmental delays, stress due to daily nuisance is also an acute impact intellectual and behavioural issues, peripheral which can progress to chronic effects after neuropathy and hearing loss38, 40, 43. prolonged exposure11. Other long-term impacts are

145 Volume 16 Number 2, June 2017 Of special concern is mercury and cadmium toxicity. physiological, and mental health effects, impacting Chronic mercury toxicity leads to Minamata disease behavioural and cognitive performance11. Hearing from ingestion of contaminated seafood containing conservation measures have been effective in methyl-mercury, or from occupational exposure reducing the rate of such decline3, 45. which mainly targets the brain by crossing the blood-brain barrier, and resulting in neurological Another health hazard is vibration, especially whole- effects that include weakness, fatigue, mercurial body vibration when compared to hand-arm tremor and widespread neuro-logical damage such vibration, due to machineries used. This vibration as loss of motor control, ataxia, tremors, sensory can cause or worsen spinal cord disorders3. Heat loss affecting vision, hearing, and speech40,41. exhaustion and miliaria rubra has been reported due Chronic cadmium exposure results in nephro- and to heat and humidity but UV exposure and radiation osteo-toxicity and manifests as ‘Itai-Itai’ (‘Ouch- at mining sites are not associated with increased Ouch’) disease, characterised by multiple fractures, risk of skin cancers or other health problems3, 24, 25. mixed pattern of osteoporosis, osteomalacia and renal tubular dysfunction42. This has been Studies have linked respiratory symptoms such as associated with lung malignancies and emphysema36. cough, wheeze and rhinitis to bauxite mining3. In some earlier studies, bauxite exposure has been Impact on Health due to Noise linked to small decrements in FEV1 but recent Abdullah et al. reported that noise pollution affects occupational health studies could not be linked to bauxite miners and neighbouring communities, as such reductions26-28. There has been a reported case mining is carried out around the clock11. Potential of pulmonary fibrosis, but bauxite is not associated health effects include noise-induced hearing loss, with pneumoconiosis. loss of hearing sensitivity, and sleep disturbances. Noise has been associated with cardiovascular and In terms of cancer incidence, bauxite mining has not physiological effects along with behavioural and been associated with malignancies such as skin cognitive impacts11. Residents living near mines are cancers or pleural mesothelioma, and not linked to subjected to mental stress11. Due to high iron oxide increased or combined cancer mortality3, 24, 30. content, nearby communities get tainted dark red and this visual disturbance can cause stress. The Impact on Surrounding Communities health impact of bauxite dust on individuals, water During our literature review, we found very few and food sources also exert its toll. papers that discussed the impact of bauxite mining on surrounding communities because most mines are DISCUSSION located in remote areas with well-defined boundaries. However, in Kuantan, mines are Environmental Impact of Bauxite Mining scattered, poorly defined and operate within or The environmental impact of bauxite mining can be near communities; with bauxite potentially causing on air, water and soil. Under air pollution, the main significant impacts on the health and lives of nearby hazard is nuisance dust which can obstruct vision3, 8, populations11. deposits on vegetation, food, and airways, thus causing long term respiratory and cardiac diseases 8, Acute impacts of mining activities include exposure 11. to bauxite dust and vector-borne diseases11. Long- term effects of bauxite mining can be attributed to Details about water pollution are not known as no bauxite dust, comprising particles of varying size study was conducted to explore the effects of which can contaminate food sources and water bauxite ingestion in humans. Moreover, drinking supply, causing respiratory infections or diseases11. water pollution is not the only concern as bauxite The potential of leaching of heavy metals and and heavy metals in the sediments can be absorbed products of bauxite mining into nearby water by aquatic animals, or plants, affecting various sources is another concern as they have long-term levels of food chain13. effects on both adults and children such as neuro- toxicity, nephrotoxicity, cardiovascular diseases, Soil pollution impacts agricultural activities as the neuro-developmental delays as well as increased fertile topsoil is stripped bare and restoration risk of malignancies and mortality11, 35-37. The health efforts are not sufficient to return barren land to of nearby residents is affected by noise pollution the former state16. Heavy metals in soil are which may result in reduced hearing sensitivity and absorbed, which raises issue of food safety among noise-induced hearing loss11. All these impacts will consumers19. Moreover, habitat destruction reduces cause mental stress to nearby residents. the diversity of flora and fauna, which is vital for identity of Malaysia as a tropical forest country. PERMISSIBLE EXPOSURE LIMITS AND BIOLOGICAL EXPOSURE INDICES OF BAUXITE CONTENTS Occupational Health Hazards Permissible Exposure Limits (PELs) of Bauxite In terms of occupational health effects of bauxite Contents mining, noise-induced hearing loss is a significant Occupational Safety and Health Administration’s hazard , with poor hearing sensitivity and sleep (OSHA) permissible exposure limits (PELs) were set disturbances, which can lead to cardiovascular,

146 Volume 16 Number 2, Dec 2017 in 1970s and have not been updated since then46. workers from the same workplace or shift have Most of the PELs are outdated and scientific data measurements exceeding BEIs. indicates inadequacy of these limits to protect worker’s health46. While OSHA’s mandatory PELs in BEIs are indices of ‘uptake’ of a chemical(s) while OSHA Z-1 Table remains in effect, it is TLVs demonstrate potential inhalation ‘exposure’ of recommended to utilize Occupational Exposure an individual or group via air monitoring. Limits (OELs) due to the belief that exposures above Discrepancies may be seen between biological these OELs may be hazardous even though they monitoring and air monitoring data for a number of comply with relevant PELs46. reasons:

Many countries have developed OELs for airborne  Physiological composition and health status vapours, particles and gases46. The American of worker: body habitus, habits, diet, Conference of Governmental Industrial Hygienists metabolic rate, age, gender, body fluid (ACGIH) has issued the Threshold Limit Values (TLVs) composition, medicine, pregnancy and for airborne concentrations of chemicals under disease state. conditions in which most workers are repeatedly  Occupational exposures: work-rate, intensity exposed without any adverse events46. Malaysia and duration, temperature and humidity, co- utilizes the PELs issued under the Occupational exposure to other irritants, skin exposure and Safety and Health Act 1994 (OSHA 1994), in other work habits. Schedule 1 of the Occupational Safety and Health  Non-occupational exposures: water and food, (Use and Standards of Exposure to Chemicals personal hygiene, residential air pollutants, Hazardous to Health Regulations 2000)47, 48. OELs for alcohol and drug intake, cigarette smoking, substances listed in OSHA Z-1 Table have been set or exposure to household products or and revised periodically46; these should be consulted chemicals from hobbies. for the latest values, and special notations, such as  Methodological causes: contamination of skin absorption. specimen and bias of selected analytical method. Biological Exposure Indices (BEIs) of Bauxite  Positioning of air monitoring device in Contents relation to worker’s breathing zone. Biological exposure indices (BEIs) are the levels that  Size and bio-availability of particles. are observed in biological specimens such as  Varying effectiveness levels of personal exhaled air, blood and urine, of healthy workers protective devices. who have chemical exposure similar to the workers 49 with inhalation TLVs . These provide guidance for LEGAL REQUIREMENTS AND STANDARDS OF biological monitoring and evaluating workers’ EXPOSURE TO BAUXITE IN MALAYSIA exposure and health risk (dosage of exposure of a worker from a chemical is reflected by biological The Department of Environment (DOE), Ministry of monitoring). Natural Resources and Environment of Malaysia have published guidelines for siting and zoning of industry BEIs are the concentrations below which most and residential areas in 2012. This is intended as a workers do not encounter detrimental health guiding document to assist project owners and effects. The chemical, its metabolites, or a relevant Federal, State and Local authorities to reversible biochemical change in chemical can be a decide on the suitability of a site for a particular BEIs determinant. However, they are not a industrial or non-industrial activity, with potentials parameter of adverse effects to diagnose to negatively impact the environment50. occupational illness. This does not demarcate between hazardous and non-hazardous exposures. The primary objective of guidelines is to ensure It is plausible that increased health risk does not appropriate selection of a site to avoid or minimize occur even when the individual’s determinant environmental conflicts which could arise as a result concentration exceeds BEIs. Investigations should be of incompatibility between the proposed project or instigated BEIs are the concentrations below which activity and its neighbors50. Avoiding conflicts most workers do not encounter detrimental health through proper siting is an element of effects. The chemical, its metabolites, or a environmental planning to achieve long term reversible biochemical change in chemical can be a project sustainability, which helps to reduce BEIs determinant. However, they are not a unnecessary cost of pollution control and improves parameter of adverse effects to diagnose public perception about the project. These occupational illness. This does not demarcate guidelines are also applicable for extraction and between hazardous and non-hazardous exposures. It production of natural resources such as minerals and is plausible that increased health risk does not occur rocks. even when the individual’s determinant concentration exceeds BEIs. Investigations should be The Environmental Quality Act 1974 (EQA 1974) instigated when worker’s specimens persistently requires that any activity which is likely to release exceed BEIs on various occasions, or majority of or discharge or emit any pollutant which may

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impact the environment, is required to obtain the considered “high risk” due to its nature to discharge relevant comment, consent or approval of the large quantities of wastewater containing high levels Director General of Environmental Quality, DOE50. of residual contaminants, and generating large These consents or approvals are regarding site’s quantities of scheduled wastes, which are difficult suitability assessment, Environmental Impact to treat50. A minimum distance of 1km is indicated Assessment (EIA), written permission, approval, and as a primary buffer. license etc. CONCLUSION The EQA 1974 relates to the prevention, abatement, control of pollution and enhancement of This review has highlighted bauxite mining environment from various industrial and non- repercussions on the environment through industrial activities and may give rise to waste or destruction of ecosystem that include harming of pollutants affecting the environmental quality50. the air, water, food, soil as well as flora and fauna of the mining areas. Bauxite mining affects the The term ‘Mine’ and ‘Mining’ is interpreted in the health of miners and surrounding communities, Mineral Development Act 1994 (Act 525) as: along with environmental pollution; this is  ‘to mine’ means ‘intentionally to mine particularly true in Kuantan due to the poor minerals and includes any operation directly demarcation and proximity of mines to the or indirectly and necessary therefore or neighbouring communities. There is still a incidental thereto, and “mining” shall be knowledge gap regarding the long-term health construed accordingly’ impacts of bauxite mining because chronic illnesses  The term ‘mineral’ is ‘a naturally occurring take time to manifest later in life. Hence, a element or chemical compound that is formed detailed research is required to identify the areas as a result of geologic processes’ which require improvement to implement measures to control and manage impacts of bauxite mining on Mining is regulated as a ‘prescribed activity’ under the environment and human health. the Environmental Quality Order 1987, and includes: 1. Mining of minerals in new areas where lease CONFLICT OF INTEREST covers an area over 250 hectares. The authors reported no conflicts of interest. 2. Ore processing, including concentration of aluminium, copper, gold or tantalum. REFERENCES 3. Sand involving an area of 50 1. IAI. Fourth sustainable bauxite mining report. hectares or more. London, United Kingdom: International Aluminium Institute (IAI), 2008. Mining is ‘a process that begins with exploration and 2. IAI. Bauxite residue management: best practice. discovery of mineral deposits and continues through UK: International Aluminium Institute (IAI), ore extraction and processing till the closure and 2015. remediation of work sites’50. In the context of 3. Donoghue AM, Frisch N, Olney D. Bauxite mining guidelines, buffer zone represents ‘separation area’ and alumina refining: process description and between two or more areas for mitigation of occupational health risks. J Occup Environ Med. potential conflicts and protection of environment50. 2014;56(5 Suppl):S12-7. Buffer zones are intended to safeguard and protect 4. Mitchell J, Manning GB, Molyneux M, Lane RE. human lives, property, comfort and well-being, and Pulmonary fibrosis in workers exposed to finely also sensitive ecological resources. The presence of powdered aluminium. Br J Ind Med. 1961;18:10- adequate buffer zone represents primary means to 23. determine whether the site is appropriate for 5. PK. T. The mineral industry of Malaysia. U.S. particular industry or activity taking account of geological survey minerals year minerals immediate and adjacent land use and yearbook. . 2004:15.1-.7. characteristics of receptors around selected sites. 6. Gardner JH, David TB. Bauxite mining restoration by Alcoa World Alumina Australia in A buffer zone is the area within which sensitive or Western Australia: Social, political, historical, incompatible land uses are prohibited or special and environmental contexts. Restoration measures are necessary to ameliorate the impacts Ecology. 2007;15(4):S3-S10. of an activity50. These areas are not alternative to 7. Bray E. U.S. Geological Survey. Mineral prevention and control at source or to high Commodity Summaries: Bauxite and Alumina. . standards of environmental management for the 2016:32-3. activities which have potential to impact 8. Petavratzi E KS, Lowndes I. Particulates from environment. Buffer zone is an added measure to mining operations: A review of sources, effects minimize off-site impacts of residues which persist and regulations Minerals Engineering 2005 despite preventive and mitigation measures. (18):1183-99. 9. Gelencser A KN, Turoczi B, Rostasi A, Hoffer Under the classification of industries and potentially Imre K et.al. The Red Mud Accident in Ajk polluting hazardous activities, bauxite mining is (Hungary): Characterization and Potential

148 Volume 16 Number 2, Dec 2017 bauxite mines and alumina refineries. Int J Health Effects of Fugitive Dust. Environ Sci Cancer. 2008;123(4):882-7. Technol 2011;45:1608-15. 25. Carvalho FP, Matine OF, Taimo S, Oliveira JM, 10. Abdullah NH MN, Sulaiman LH, Zakaria TA, Silva L, Malta M. Radionuclides and radiation Rahim DA Potential Health Impacts of Bauxite doses in heavy mineral and other mining Mining in Kuantan. Malays J Med Sci. 2016;23 operations in Mozambique. Radiation Protection (3):1-8. Dosimetry. 2013;158(2):181-6. 11. Abdullah N, Mohamed N, Sulaiman L, Zakaria T, 26. Townsend MC, Enterline PE, Sussman NB, Rahim D. Potential Health Impacts of Bauxite Bonney TB, Rippey LL. Pulmonary function in Mining in Kuantan. Malays J Med Sci. 2016 23 relation to total dust exposure at a bauxite (3):1-8. refinery and alumina-based chemical products 12. HB B. Sources and Origins of Heavy Metals. plant. Am Rev Respir Dis. 1985;132(6):1174-80. Heavy Metals in the Environment. 2005:1-27. 27. Beach JR, de Klerk NH, Fritschi L, Sim MR, Musk 13. Yi YJ YZ, Zhang SH. Ecological risk assessment AW, Benke G, et al. Respiratory symptoms and of heavy metals in sediment and human health lung function in bauxite miners. Int Arch Occup risk assessment of heavy metals in fishes in the Environ Health. 2001;74(7):489-94. middle and lower reaches of the Yangtze river 28. Dennekamp M, de Klerk NH, Reid A, Abramson basin. Environmental Pollution. 2011;159:2575- MJ, Cui J, Del Monaco A, et al. Longitudinal 85. analysis of respiratory outcomes among bauxite 14. Raymond AW FE. Heavy metals in contaminated exposed workers in western Australia. Am J Ind soils: A review of sources, chemistry, risks, and Med. 2015;58(8):897-904. best available strategies for remediation. ISRN 29. Bellot SM, Schade van Westrum JA, Wagenvoort Ecology. 2011(2011):1-50. CA, Meijer AE. Deposition of bauxite dust and 15. Lad RJ SJ. Impact of Bauxite Mining on Soil: A pulmonary fibrosis. Pathol Res Pract. 1984;179 case study of Bauxite Mines at Udgiri, Dist- (2):225-9. Kolhapur, Maharashtra State, India. Internal 30. Friesen MC, Fritschi L, Del Monaco A, Benke G, Research Journal of Environmental Sciences. Dennekamp M, de Klerk N, et al. Relationships 2015;4 (2):77-83. between alumina and bauxite dust exposure 16. Coke LB WC, Hill VG. Environmental Impact of and cancer, respiratory and circulatory disease. Bauxite Mining and Processing in Jamaica. Social Occup Environ Med. 2009;66(9):615-8. and Economic Studies. 1987;36(1):289-333. 31. Health aspects of air pollution: Results from the 17. A M. The opencast bauxite mining in N.E. WHO project “systematic review of health Ghiona: Ecoenvironmental impacts and aspects of air pollution in Europe”. geomorphological changes (Central Greece). Copenhagen: World Health Organization (WHO), Journal of Geography and Regional Planning. 2004. 2011;5(2):21-35. 32. Schuepp K, Sly P. The developing respiratory 18. Zhou H, Yang W, Zhou X, Liu L, Gu J, Wang W, tract and its specific needs in regard to et al. Accumulation of Heavy Metals in ultrafine particulate matter exposure. Pediatr Vegetable Species Planted in Contaminated Respir Rev. 2012;13:95-9. Soils and the Health Risk Assessment. Int J 33. Flaten TP. Aluminium as a risk factor in Environ Res Public Health. 2016;13(3). Alzheimer's disease, with emphasis on drinking 19. Wright V JS, Omoruyi FO. Effect of Bauxite water. Brain Res Bull. 2001;55(2):187-96. Mineralized Soil on Residual Metal Levels in 34. Iron overload: Iron Disorders Institute; 2009 Some Post Harvest Food Crops in Jamaica. Bull [cited 2016 June 10]. Environ Contam Toxicol 2012;89. 35. Ratnaike R. Acute and chronic arsenic toxicity. 20. Wesdock JC, Arnold IM. Occupational and Postgrad Med J 2003;79(933):391-6. environmental health in the aluminum industry: 36. Nawrot T, Plusquin M, Hogervorst J, Roels H, key points for health practitioners. J Occup Celis H, Thijs L, et al. Environmental exposure Environ Med. 2014;56(5 Suppl):S5-11. to cadmium and risk of cancer: a prospective 21. SK N. Noise Impact Assessment and Prediction in population-based study. Lancet Oncol. 2006;7 Mines Using Soft Computing Techniques (2):119-26. Rourkela, Odisha, India National Institute of 37. Barceloux D. Chromium. J Toxicol Clin Toxicol Technology Rourkela; 2012. 1999;37(2):173-94. 22. Decibels D. Decibel Exposure Time Guidelines 38. Flora G, Gupta D, Tiwari A. Toxicity of lead: A 2016 [23-05-16]. Available from: http:// review with recent updates. . Interdisciplinary dangerousdecibels.org/education/information- Toxicology 2012;5(2):47-58. center/decibel-exposure-time-guidelines/. 39. Lustberg M, Silbergeld E. Blood lead levels and 23. Vanerkar AP, Kulkarni NP, Zade PD, Kamavisdar mortality. Arch Intern Med 2002;162(21):2443. AS. Whole body vibration exposure in heavy 40. Satoh H. Occupational and environmental earth moving machinery operators of toxicology of mercury and its compounds. Ind metalliferrous mines. Environ Monit Assess. Health. 2000;38(2):153-64. 2008;143(1-3):239-45. 41. Bernhoft R. Mercury Toxicity and Treatment: A 24. Fritschi L, Hoving JL, Sim MR, Del Monaco A, Review of the Literature. J Environ Public MacFarlane E, McKenzie D, et al. All cause Health 2012. mortality and incidence of cancer in workers in

149 Volume 16 Number 2, June 2017 42. Bernhoft R. Cadmium Toxicity and Treatment. ScientificWorldJournal 2013;2013(394652). 43. Crossgrove J, Zheng W. Manganese toxicity upon overexposure. NMR Biomed. 2004;17(8):544-53. 44. Das K, Das S, Dhundasi S. Nickel, its adverse health effects & oxidative stress. Indian J Med Res 2008;128(4):412-25. 45. Donoghue AM, Frisch N, Dixon-Ernst C, Chesson BJ, Cullen MR. Hearing conservation in the primary aluminium industry. Occup Med (Lond). 2016;66(3):208-14. 46. OSHA. Permissible Exposure Limits – Annotated Tables Washington, US: Occupational Safety and Health Administration (OSHA); [cited 2016 April 15]. Available from: https://www.osha.gov/ dsg/annotated-pels/. 47. ILO. Chemical Exposure Limits Geneva, Switzerland: International LAbour Organisation (ILO); 2016 [cited 2016 April 15]. Available from: http://www.ilo.org/safework/info/publications /WCMS_151534/lang--en/index.htm. 48. Occupational Safety and Health (Use and Standards of Exposure of Chemicals Hazardous to Health) Regulations (2000). 49. ACGIH. Biological Exposure Indices (BEI) Introduction Ohio, US: American Conference of Governmental Industrial Hygienists (ACGIH); 2012 [cited 2016 April 15]. 50. Department of Environment MoNRaEM. Guidelines for siting and zoning of industry and residential areas. 2012.

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