Document 8rVXab6yeB5GdROY8bajLEDe

14256997033 2002-02-26 19:09:21 (GMT), page 22 21 The QAMA McGill researchers have also claimed that even if fiber mined from Canada causes mesothelioma and lung cancer, studies show that the dose required to induce these diseases is so high that there is no practical risk to current workers. Unfortunately, studies of textile workers exposed to the same fiber have revealed a dose response curve that indicates that the Canadian fiber is fifty fold more potent then the QAMA studies show. Dr. McDonald described this inconsistency, the "slope of the exposure response lines for lung cancer in the textile industry was some fifty times steeper than that observed in Quebec chrysotile miners and millers..." (McDonald 1998a) The QAMA-McGill researchers have dubbed this variation the "textile mystery and have failed to provide any kind of explanation for it" (McDonald 1998b) Ignoring the textile dose response data, they have vociferously opposed the French chrysotile ban before the WTO and in testimony for chrysotile asbestos product manufacturers have claimed that their chrysotile products did not in ary way contribute to worker's asbestos caused mesotheliomas and lung cancers. Incredibly, JC McDonald served as co-counsel forthe Canadian legal team and presented partofCanada's opening argument at the appeal ofthe WTO ruling on the French ban.(Barry Castleman 2000) McDonald summarily dismissed miscalculations in dose measurement and errors that occurred when the Canadian researchers converted particle to fiber counts as possible explanations for this apparent disparity. He asserted, "There is nothing to suggest that the estimates of cumulative exposures in the relevant cohorts were seriously in error although questions of peak exposures and fibre size distributions in ambient air have not been examined" [Emphasis added] [m However, the QAMA-McGill researchers evaluated the quality of the dose estimates quite differently when they first reported them. (Gibbs and LaChance 1972;Gibbs and LaChance 1974) While McDonald flatly stated that errors in measurement or actual 21