There is a story that Charlemagne owned a tablecloth of woven asbestos that was cleaned after meals by being thrown in a fire. The remarkable properties of asbestos — its nonflammability, poor heat conduction, fibrousness and ubiquity in the earth's crust — has earned it commercial use in everything from insulation materials to theatre curtains, cement pipes, shingles, gaskets, brake linings, sealants and rope. It has even turned up (as a contaminant of talc) in children's crayons. Almost everyone in the Western world has been exposed to asbestos.
One of the world's largest deposits of asbestos was discovered circa 1878 about 100 km south of Quebec City. Now the site of the town of Asbestos and of the world's largest asbestos mine, the area produces about one third of the world's supply. Indeed, Canada is the only Western country that continues to produce asbestos in large quantities. Thus the call by the Collegium Ramazzini for a worldwide ban on the mining and use of asbestos (see page 489)1 is primarily directed at us.
The Greek root of “asbestos” means “unquenchable,” which today might describe the thirst of legal firms for lawsuits related to the health effects of asbestos exposure and of the asbestos industry for new markets to make up for lost manufacturing opportunities in the West. The scientific debate about the hazards of asbestos has been similarly inextinguishable. Occupational studies carried out in the 1970s mainly at McGill University by Corbett Macdonald and colleagues and at Mount Sinai School of Medicine in New York by the late Irving J. Selikoff and his associates led both groups to almost opposite conclusions. Macdonald, now professor emeritus at McGill, made a strong case that mesothelioma, lung cancer and asbestosis could be attributed mainly to a particular type of asbestos, amphibole (now no longer mined) and that the currently produced asbestos, chrysotile, was much less harmful. Selikoff disagreed, as do the members of the Collegium Ramazzini, which he founded in 1972 to “assess present and future potential for injury of disease attributable to the environment or workplace.”
To further debate and provide editorial balance to the Collegium's proclamation we asked Michel Camus2 (see page 491) to respond and Jack Siemiatycki3 (see page 495) to review what we know about the health risks of asbestos and the substitute products that will have to be used if asbestos is banned.
We agree with Siemiatycki's proposal that a panel of experts with no “significant experience or interest in asbestos research” review the public health implications of asbestos and the efficacy and the hazards of alternative materials. As the only Western country still producing large quantities of asbestos, Canada has a responsibility to lead this effort and to abide by the panel's recommendations. In one of its ancient uses, asbestos was woven into the wicks of oil lamps to make them burn more slowly. Generating, one imagines, more light than heat. — CMAJ
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