Carcinogenicity of asbestos: convincing evidence, conflicting interests.

In spite of hard epidemiological and clinical evidence associating asbestos fibre with asbestosis and cancer, the issue is controversial and likely to remain so. The focus is now shifting to non-occupational exposure, differential risk to various asbestos fibre types and the relatively low level of carinogenicity of the chrysotile form. This creates further space for scientific debate and the opportunity to form a considered opinion. However, the situation may take a worrisome turn if some of these scientific inquiries are used by market forces to their advantage. A look at the history of corporate activities in asbestos-related research reveals a disturbing trend. Information that was made available, through legal interventions, clearly shows how for half a century the asbestos industry in collaboration with some academic leaders of occupational medicine successfully suppressed evidence against asbestos. In developing countries, extensive and aggressive marketing continues by chrysotile producers, mainly Canadian companies. There is renewed pressure on this part of the world since new use of asbestos has been almost completely discontinued in the developed countries as a result of public pressure and state prohibitions. In this scenario, relaxation of public health control over any form of asbestos should be opposed. It is extremely dangerous and scientifically untenable to say that chrysotile asbestos can be used without risk. It has been identified as a potent human carcinogen, and remains so. However, some restraint must be exercised while dealing with asbestos that has already been released into the environment. Disturbing it unnecessarily may cause more harm than good.