[Health effects of non-occupational exposure to asbestos]

Mesothelioma has occurred in a relative large number not only among miners but also among non-occupationally exposed persons living in the northwestern region of Cape State of South Africa, where crocidolite is mined and transported. The long-term residents of Thetford Mines in Quebec Province, Canada, who have never engaged in mining and milling of chrysolite have not shown an excess mortality of respiratory diseases. Tremolite in soil is responsible for mesothelioma among residents of certain geologic regions such as Cyprus, Corcica, northwestern Greece and Turkey. An increased prevalence of malignant mesothelioma has been reported among residents of three Turkish villages due to exposure to erionite fibers having a high carcinogenic potency. Mesothelioma has infrequently developed in wives who were exposed while washing the work clothes of their husbands contaminated with asbestos, especially amphiboles. The levels of airborne asbestos in public buildings and schools in the U.S.A. and England having walls and ceilings constructed with asbestos containing materials are approximately 1/100 of the permissible concentration of 0.2 f/cm3. The estimated risk from asbestos exposure in schools and buildings is lower than the level of other risks in other society. During the work of removing asbestos from buildings the asbestos concentration is remarkably increased and this persists for many weeks thereafter. The level of asbestos fibers released from brake linings of motor vehicles is higher along roads with heavy traffic, at intersections, and near toll booths than elsewhere. The concentration of asbestos fibers released from motor vehicles is generally low and not of the level to induce mesothelioma.