Journal of Science (JOS) Vol. 3, No. 1, 2013, ISSN 2324-9854 Copyright © World Science Publisher, United States www.worldsciencepublisher.org
241
Asbestos: A potential food contaminant and associated safety risks to consumers 1
Anupam Roy, 2Kalyani Khanra and 3Nandan Bhattacharyya
1&2
Department of Biotechnology, Panskura Banamali College, Panskura RS, Dist. Purba Medinipur, Pin -721152, West Bengal, INDIA. 3 Principal, Panskura Banamali College, Panskura RS, Dist. Purba Medinipur, Pin -721152, West Bengal, INDIA.
Email:
[email protected] Abstract – Due to low cost of the material, asbestos is being used (mostly in its powder form) profusely as a food adulterant particularly in developing countries like India. Unfortunately, a large section of Indian consumers are unaware about the risk of persistent intake of this toxic silicate mineral. This leads to involuntary exposure to this carcinogenic food adulterant leading to different degrees of serious lung problems that may lead to even lung cancer. This paper attempts to review the scope of this food adulteration problem, and its implications on consumers and handlers. Finally, this paper is an effort to generate awareness on health impact(s) that this food adulterant may have upon sustained exposure. Keywords – Asbestos, Toxic, Adulterant, Regulation
1. Introduction Asbestos sheet is a common roofing commodity used in the rural areas of India. Popularity of asbestos in these areas is due to low cost of the material, and its effectiveness as protection from sun, rain and other natural calamities (Tossavainen et al., 2004). Besides, due to high durability and tensile strength, asbestos is used in numerous other places including water pipes, manufacture of pressure and non-pressure pipes used for water supply, irrigation, sewage and drainage system in urban and rural areas, asbestos laminated products, textiles, tape, packing ropes, gland packing, brake lining and jointing used in industries like automobile, heavy equipment, petro-chemicals, nuclear power plants, fertilizers, thermal power plants, transportation, defense, etc. Instead of its wide application the health hazardous effect cannot be under looked as there are several scientific evidences of health effects. 2. Classification and general properties of Asbestos Asbestos is a geologic term refers to a group of naturally occurring silicate minerals that form fibers during crystallization (Perry et al., 2004). On the basis of crystal structure asbestos are classified in two broad groups – (i) ‘serpentine asbestos’ and (ii) ‘amphibole asbestos’. Serpentine asbestos includes chrysotile, a fibrous hydrated magnesium silicate material
[Mg3Si2(OH)4] which is generally known as white asbestos. Amphibole types, on the other hand, include amosite (brown asbestos), tremolite, actinolite, anthophylite, and the crocidolite (blue asbestos). The properties like “composed of strong and flexible fibers, resistant to heat, corrosion, abrasion etc” are the common features of asbestos. Chrysotile is the most common type of asbestos used for commercial purposes, and it accounts for 90 percent of the world’s production of asbestos (Ramanathan et al., 2001). Asbestos cement industry consumes the largest amount of Chrysotile asbestos throughout the world (IPHE;Asbestos Health and Environment, An In-Depth Study). The asbestos cement products are strengthened by addition of 5% to 10% of chrysotile asbestos during mixing with cement (Dave et al., 2005) . Around 1 lakh tons of Chrysotile asbestos is consumed per year in India. Asbestos tend to break into microscopic fibre and once released in air may stay suspended in the air for hours or even days. The meaning of ‘asbestos’ in Greek is ‘unquenchable’ or ‘indestructible’. It is the nature of fibre that makes them resistant to chemicals and heat, they cannot be vaporized or dissolved in water, and they are not biodegradable. 3. Toxic effect of asbestos and reason behind it Underneath the apparent innocence lies the toxic truth of asbestos. It is a toxic mineral producing debilitating health effects in humans, and is abundantly with very
Anupam Roy et al., JOS, Vol. 3, No. 1, pp. 241-243, 2013
little awareness among majority of the users and handlers. The applications of asbestos are economically beneficial, but it is burden to human and environmental health by far outweighs economic benefits of its use. All types of asbestos posses some degree of toxicity. The toxicity of Chrysotile is assumed to be minute with respect to amphibole asbestos, which experts generally regard as more hazardous. Asbestos is made of microscopic bundles, which may become airborne. Airborne particles may get inhaled into the lungs, where they cause significant health problems. The ‘safe level’ of exposure of asbestos is still an area of extensive research. The greater and the longer the exposure time, higher is the risk of developing asbestosrelated disease(s). Occupational Safety and Health Administration (OSHA) regulates that 0.1 fiber per cubic centimeter of air (0.1 f/cc) is unsafe((GETF 2003).Detection of air-pollution with asbestos has experienced evolution with time, and currently, it is as determined by phase contrast microscopy (PCM). One of the major determinant of this level of asbestos being the upper tolerable limit was technological limitations that existed at the time of this piece of regulation was established (i.e., 0.1 f/cc was the smallest amount of asbestos that could be reliably detected at the time with the chosen technology, PCM ) (Schlecht et al., 1995). Some of the health problems associated with exposure to asbestos is discussed below. Asbestosis or “asbestos-induced pulmonary fibrosis” is a lung disease that causes scarring of lungs. It happens due to the long-term exposure to high doses of asbestos that results deposition of collagen in the lungs. Our body generates an acid as an attempt to dissolve the asbestos fibers in the lungs, but the acid often has little effect on the asbestos and instead damages lung tissue. That results the scarring of the lungs. The time taken for the development of this condition or the latency period of this disease is 25-40 years (Lippmann and Morton et al., 2000). Mesothelioma is a malignant tumor or cancer of the lining of the lung and chest and/or the lining of the abdominal wall. This usually occurs after years of occupational or environmental exposure to asbestos. The latency period for Mesothelioma is vary from 15-50 years (USEPA2004). Lung Cancer or bronchogenic carcinoma can also be caused by asbestos exposure. Cigarette smoking in combination with exposure to asbestos significantly increases risk of lung cancer (by about 50%). Cancer of the gastrointestinal tract can also be caused by asbestos. The latency period for lung cancer is 15-30 years. Stomach and bowel cancers are also developed due to exposure to asbestos. Asbestos fibre reach to the mentioned part of the body through the ingestion of fibers expelled from the lungs (GETF-2003; USEPA2004). It is a well reported fact that occupational exposure of asbestos may cause simple inflammatory reaction, asbestosis, to bronchogenic carcinoma (Mossman et al.,1990). Evidence shows that asbestos currently kills around 4000 people a year in Great Britain. The increase in number is expected at least until 2016. Indian scenario is also alarming. About two to three million workers suffer from diseases associated with exposure to asbestos
242
and other dusts and fibres. Due to toxicity of asbestos, it is banned in almost 40 countries including European Union, Australia, Honduras, Uruguay, and others. Recently, Japan has also banned asbestos use, except in cases where there is no alternative. It should be kept in mind that the level of air pollution is generally reported to be elevated in the area surrounded by asbestos industries. Possible asbestos emission points are during processing of these products including feeding of asbestos fibre into mixing, blending of the mixture, cutting and finishing of final products. If the rate of emission is continuously monitored, and fibre control technologies are in place, the emission may be reduced to acceptable level. 4. Asbestos and Indian economic scenario India, being a developing country, has enormous infrastructure needs. Its immense population requires reliable and low-cost materials for housing. Chrysotile meets this increasing demand for housing and civil works that are part and parcel of India’s growing economy. India hosts nearly 673 small scale asbestos mining and milling facilities and 33 large scale asbestos manufacturing plants including 17 asbestos cement product manufacturing plant and 16 other than asbestos cement product manufacturing plant5. A survey conducted on U.P. Asbestos Limited, Mohanlalganj, Lucknow and Allied Nippon Pvt Ltd., Ghaziabad (U.P), shows higher lung function impairment in the subjects exposed for more than 11 years.(Annual Report of Industrial Toxicology Research Centre -2001-2002, India) Indian government is inclined to effectively implement safe and responsible use of asbestos and asbestos cement product rather than enforcing a straight forward ban. The activities associated with the use of asbestos in India are now under better supervision and regulatory control. The safety measures that industry should comply with are now strictly regulated, and various levels of Government agencies monitor to ensure safe and controlled use of asbestos in India. More recently Government of India published an Assessment Guidance Manual called “Environmental Impact Assessment Guidance Manual for asbestos-based industries” under Ministry of Environment & Forests. This manual furnishes specifications to be followed in asbestos based industry regarding land, water environment, air and meteorological, noise, biological environment, socio-economic environment and solid waste facilities (Environmental Impact Assessment Guidance Manual for asbestos-based industries” Ministry of Environment & Forests, Government of India, 2010). Needless to say that the ignorance still prevail in the field of governance and monitoring of relevant regulatory implementations. People using asbestos sheet for roofing generally belong to lower or other financially modest population groups. They often cook their food in the open wood fire under asbestos roofing. This results in flaking and pitting on asbestos cement roof exposing asbestos, making it airborne. They paint their asbestos roofing with emulsion paint which deteriorates it rapidly resulting discoloration and mould growth. The effect of surface
Anupam Roy et al., JOS, Vol. 3, No. 1, pp. 241-243, 2013
weathering also exposes asbestos from asbestos cement roof. Also, height of a rural cottage, roofed by asbestos cement, is too small to have effective ventilation.
243
4. Asbestos Health and Environment, An In-Depth 5.
5. Asbestos and food contamination Besides, some evidence suggests that use of finely powdered asbestos fibre mixed with talc to polish rice with the aim of making it attractive for consumer is quite prevalent adulteration of the major cereal grain that mostly go through post-harvest processing in rural areas of India. Such adulterations ring the alarm bell concerning safety issues and awareness among consumers. In this regard, appropriate Government agencies should not only focuses on informing unaware user about the toxicity of asbestos on its potential hazards as food contaminants, but also should focus on a strong surveillance network for detecting any possible food contamination. 6. Conclusion In India an estimated one-lakh people are exposed to asbestos only at work place (Joshi et al., 2003). This estimated calculation would increase in folds if the proper data of domestic exposure would be added. Besides the new and most harmful additional application of food adulteration may cross the limit that cannot be postulated in that moment. The governance and monitoring from both the governmental and nongovernmental agencies should come in contact with military-footing making aware about the health hazards of asbestos and its deadly food adulteration application. References:
6.
7.
8.
9.
10.
11. 12.
1. Tossavainen, A., Global use of Asbestos and Incidence of mesothelioma. Int. J Environ. Health,. 2004, 10, 5-22. 2. Perry, A., A discussion of Asbestos Detection Techniques for Air and Soil; National Network of Environmental Management Studies, USEPA, 2004, pp1-2. 3. Ramanathan , A.L. and Subramaniam, L., Present status of asbestos mining and related health problem in India. –A survey India Health, 2001.
13.
14.
Study, Institute of Public Health Engineers, Kolkata, India, 2002. Dave, S.K. and Beckett, W.S., Occupational asbestos exposure and predictable asbestos-related disease in India. Am Rev Respir,. 2005; 48:43-137. Asbestos strategies: lessons learned about management and use of asbestos. Report of Findings and Recommendations on the Use and Management of Asbestos. Global Environment and Technology Foundation (GETF). 2003. www.getf.org/asbestosstrategies/includes/Asbestos_ Strategies_Report.pdf (20 Aug. 2004). Schlecht, P. C. and Shulman, S. A., Phase Contrast Microscopy Asbestos Fiber Counting Performance in the Proficiency Analytical Testing Program. American Industrial Hygiene Association Journal,. 1995. 56: 480-488. Lippmann and Morton.,. Asbestos and Other Mineral and Vitreous Fibers. Environmental Toxicants: Human Exposures and Their Health Effects. Ed: Morton Lippmann. John Wiley and Sons: 2000,. New York. Environmental Protection Agency (USEPA). 2004. What is asbestos? U.S. Environmental Protection Agency website. www.epa.gov/asbestos/asbe.pdf (20 Aug. 2004). Mossman, B.T,. Bignon, J., Corn, M., Seaton, A., and Gee, J.B., Asbestos: Scientific Development and implication for public policy. Science 1990; 294301. Annual Report of Industrial Toxicology Research Centre (2001-2002), India Environmental Impact Assessment Guidance Manual for asbestos-based industries” Ministry of Environment & Forests, Government of India,2010. Occupational Safety and Health Administration (OSHA). 1997. Asbestos in Air. ID-160. www.osha.gov/dts/sltc/methods/inorganic/id160/id1 60.html (20 Aug. 2004). Joshi TK, Gupta RK. Asbestos-related morbidity in India. Int J Occup Env Health 2003; 9: 249-53
