FIBER LEVELS AND DISEASE IN WORKERS FROM A FACTORY PREDOMINANTLY USING AMOSITE

The Cape Boards Plant at Uxbridge produced insulation board containing amosite asbestos between 1947 and 1973 with only small amounts of chr ysotile. After 1973 only amosite was used. In this study we examined l ung samples from 48 workers who had been employed at the plant and who had come to autopsy. The study investigated the fiber levels against the lung pathology including amount of interstitial fibrosis and numbe rs of ferruginous bodies. The degree of interstitial fibrosis and numb er of asbestos bodies were graded and the tissues were analyzed by tra nsmission electron microscopy and energy dispersive X-ray analysis and the fibers counted and typed. The 48 cases included 5 mesotheliomas a nd 14 lung cancers. The mineral analysis results were dominated by the amosite fiber levels. The amounts of chrysotile were relatively small . There were higher levels in lung cancer cases than mesotheliomas and higher levels in mesothelioma cases than those who had died from nona sbestos related diseases. Analysis of the lung tissues showed a consis tent pattern of high amosite levels, which confirms the impression tha t amosite was the predominant form of asbestos used and also indicates that the factory had been a very dusty one.