Exposure to asbestos in Monfalcone, Italy. A necropsy-based study.

The Monfalcone area in north-eastern Italy (total population, about 60,000) is a small industrial district in which shipbuilding is the main industry. We examined thoracic cavities for hyaline pleural plaques and routine lung sections for asbestos bodies in 1765 necropsies performed at Monfalcone Hospital. In 553 cases, we also isolated and quantified asbestos bodies in the lungs (Smith-Naylor's method). Occupational histories were obtained from the relatives of 798 patients. The prevalence of pleural plaques was significantly higher (p less than 0.001) among residents of the Monfalcone region (73.6% of men, 26.7% of women) than among nonresidents. Similarly, asbestos bodies were found more frequently in lung sections from residents. A good correlation was observed between pleural plaques and the asbestos body content of the lung (Spearman's correlation coefficient, 0.53). Different occupational groups showed very marked differences in the prevalence of plaques in general, in the prevalence of large plaques and in the numbers of asbestos bodies in the lung. Subjects who had worked in the shipyard or in a sodium carbonate factory had the highest indices. Exposure to asbestos had occurred at work for the large majority of men for whom data on occupation had been collected and through domestic contacts for the large majority of women. In a small portion of cases, environmental exposure could not be excluded as the cause of the objective signs. Pleural plaques, the asbestos body content of the lungs and occupational history must be considered together in monitoring exposure to asbestos in a given geographical area.