Chrysotile is an inert material and is not toxic to touch, smell or ingestion. Chrysotile fibre can be an occupational health hazard only when its dust is respirable and becomes airborne and when such a dust is inhaled in excessive amounts over a prolonged period. Chrysotile fibre is not a hazard when proper dust control procedures are in operation. Low level exposure to chrysotile, within the limits stipulated by the national and international health authorities poses no measurable risk.
Health risk at a workplace due to inhalation of respirable dust is not unique to chrysotile fibre. Virtually all respirable materials are potential health risks when used in uncontrolled conditions. Chrysotile is only one among such fibres.
In the Western world, during the period of ignorance asbestos fibres of all types including amphibole varieties, in loose form, was extensively sprayed on ceilings and structures to conserve heat. It has been proven by later scientific studies that the health problems that were evidenced in the subsequent decades in the West were due to unregulated and irresponsible usage of asbestos, largely consisting of amphibole varieties. Mining, production and usage of these amphibole varieties of asbestos have subsequently been given up.
In today's well controlled and regulated industrial plants using only Chrysotile type of fibre, occurrence of such diseases do not arise. Nor are any health risks associated with the products containing chrysotile-cement mix, such as corrugated roofing sheets, plain sheets, pressure pipes, etc. etc. as the chrysotile fibre is bonded with cement and cannot escape in to the surrounding environment.
Indian Experience
Permissible Exposure Limit Value (PELV) - As technology has advanced the exposure of workers to Chrysotile fibre in the manufacturing process is kept well below the Permissible Exposure Value (PEV) of 1 f/cc as stipulated by the Ministry of Labour in the Factories Act.
During 2004 & 2005 The Directorate General Factory Advice Service and Labour Institutes (DGFASLI), under the Ministry of Labour, Government of India, undertook studies on "Health Status of Workers in the Asbestos Industry" and "Status of Work Environment in Asbestos Products Manufacturing Industry".
These studies covered 9 factories using Chrysotile fibre in the manufacturing process. A total of 702 workers in the age group of 20 to 50 years were covered. The studies concluded that the workplace emission levels in these industries, were well below the stipulated levels of emission, that is, 1 fibre/cubic centimetre and that no case of asbestosis was detected during the study. (asbestosis is a respiratory disease associated with excess inhalation of asbestos fibre of various types over a prolonged period). Click here for DGFASLI Reports
References:
Health risk at a workplace due to inhalation of respirable dust is not unique to chrysotile fibre. Virtually all respirable materials are potential health risks when used in uncontrolled conditions. Chrysotile is only one among such fibres.
In the Western world, during the period of ignorance asbestos fibres of all types including amphibole varieties, in loose form, was extensively sprayed on ceilings and structures to conserve heat. It has been proven by later scientific studies that the health problems that were evidenced in the subsequent decades in the West were due to unregulated and irresponsible usage of asbestos, largely consisting of amphibole varieties. Mining, production and usage of these amphibole varieties of asbestos have subsequently been given up.
In today's well controlled and regulated industrial plants using only Chrysotile type of fibre, occurrence of such diseases do not arise. Nor are any health risks associated with the products containing chrysotile-cement mix, such as corrugated roofing sheets, plain sheets, pressure pipes, etc. etc. as the chrysotile fibre is bonded with cement and cannot escape in to the surrounding environment.
Indian Experience
Permissible Exposure Limit Value (PELV) - As technology has advanced the exposure of workers to Chrysotile fibre in the manufacturing process is kept well below the Permissible Exposure Value (PEV) of 1 f/cc as stipulated by the Ministry of Labour in the Factories Act.
During 2004 & 2005 The Directorate General Factory Advice Service and Labour Institutes (DGFASLI), under the Ministry of Labour, Government of India, undertook studies on "Health Status of Workers in the Asbestos Industry" and "Status of Work Environment in Asbestos Products Manufacturing Industry".
These studies covered 9 factories using Chrysotile fibre in the manufacturing process. A total of 702 workers in the age group of 20 to 50 years were covered. The studies concluded that the workplace emission levels in these industries, were well below the stipulated levels of emission, that is, 1 fibre/cubic centimetre and that no case of asbestosis was detected during the study. (asbestosis is a respiratory disease associated with excess inhalation of asbestos fibre of various types over a prolonged period). Click here for DGFASLI Reports
References:
- Gaensler EA, Asbestos-Related Disorders - Clinical and Epidemiological Aspects, Proceedingsof the Fleischner Society Eighteenth Annual Symposium on Chest Disease. Montreal 1988,17-31.
- Doll R. Mortality from Lung Cancer in Asbestos Workers. British Journalof Industrial Medicine, 1985, 12:81
- Berry G.Newhouse ML.Turok M; combined Effects of Asbestos Exposures and Smoking on Mortality from Lung Cancer in Factory Workers. Lancet 1972, 2:476
- Wagner J.C. et al, British Journal of Industrial Medicine 45: 305-308 (1988).
- Peter Elmes; Mesotheliomas and Chrysotile; The Annals of Occupational Hygiene Vol.38, No.4, August 1994, 547-553
- The National Study on Status of Work Environment in Asbestos Products Manufacturing Industry, 2005.
- The National Study on Status of Workers in the Asbestos Industry, 2004.
This is a great article. The key to prevention is increased education and awareness. Regards, TM http://www.mesorc.com/
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