The debate on banning asbestos

The data now seem to clearly refute certain old ideas about asbestos, including the notions that lung cancer cannot occur without obvious interstitial fibrosis on chest film, that chrysotile does not cause lung cancer and that there is no real interaction between smoking and asbestos exposure except among insulation workers. As a consequence of these old beliefs, claims from smokers who were exposed to asbestos and developed lung cancer have been denied for years by workers' compensation boards, often on the grounds that smoking represented the greater risk. However, a smoker exposed to asbestos is more than twice as likely as a smoker who was not exposed to asbestos to die of lung cancer (whether there is a synergistic effect at that level of exposure or not), a conclusion supported by the totality of the literature and individual studies of chrysotile-exposed workers in which the data have been so analyzed.(5) Thus, if one looked at a population of smoking asbestos workers who developed lung cancer and compared them only with unexposed smokers who developed the disease, one would conclude that occupational exposure was the cause of more than half of the cases; this is the presumptive criterion for an occupational disease. A strong case could be made that the risk conferred by exposure to asbestos for a smoking worker should be compared with the background risk for other smokers, not nonsmokers. By that standard, many claims now denied would be accepted. The proposal to ban asbestos(7) is based on arguments that neglect certain facts. Although I agree that the dusty asbestos workplaces that existed for 7 or more decades resulted in excessive exposure and undoubtedly caused malignancies, current industry regulations have dramatically improved workplace conditions. Anxieties about asbestos were initiated and then amplified by the US Environmental Protection Agency (EPA) beginning in the 1970s and continuing well into the 1980s. At one point the EPA estimated that 100 to 8000 schoolchildren would die prematurely because of exposure to asbestos in school building materials. Without evidence, the EPA came to believe, at one point, that a single asbestos fibre could cause cancer. Such claims generated enormous media attention and caused public panic. In 1990, EPA Director W.K. Reilly admitted, "[We] must accept a share of the responsibility for the misperceptions that led to the unwarranted anxiety and unnecessary asbestos removal."(8) This statement, however,