[Is malignant mesothelioma of the pleura only an occupational disease?].

Ten cases of pleural malignant mesothelioma identified histologically at the Department of General Medicine in May 1983-June 1987, are examined in this paper. Occupational risk factors and clinical features are discussed. Only one patient (10%) was subjected to occupational risk of asbestos exposure (as a smith) while the other nine patients showed a negative anamnesis for direct or indirect asbestos exposure. However, one of these patients was a tram-driver. The patients' mean age was 69 years old. 7 patients were males. 7 patients were born in an industrialized urban environment, 3 were born in an agricultural environment: all had been living in Milan for many years. Pleural fluid cytology was only useful in the diagnosis of 2 cases. This study suggests that pleural malignant mesothelioma is a neoplasm which also affects people not exposed to asbestos at work and that its frequency is increasing. The most probable cause is environmental contamination by asbestos of urban industrialized areas. Thus, it is necessary to eliminate this mineral from all manufacturing processes in which asbestos is not indispensable.