Underestimation of Chrysotile Health Risk due to Under-ascertainment of Mesothelioma: Evidence from a Century of Connecticut's Experience with the "Magic Mineral".

Over a century ago, Connecticut industry began using chrysotile asbestos. Chrysotile found a home in several factories that used it exclusively or predominantly. The occurrence of mesothelioma in 4 of those factories is the subject of this paper-2 have been reported previously and are updated here with new information; one was the subject of a prior internal corporate study that was never published; one is reported here for the first time. Twenty-four cases of mesothelioma have been identified among these workers, including several who had no known amphibole exposure. It is likely that additional cases of mesothelioma have been missed. The full scale of the hazard may never be completely known, but reports such as the present one add to the weight of evidence that chrysotile causes mesothelioma in humans and that the full extent of the epidemic is probably wider than retrospective studies have revealed. Continued vigilance is required.