Mesothelioma and lung tumors attributable to asbestos among petroleum workers

Background Asbestos exposure has been definitively found to be associated w ith both mesothelioma and lung cancer. Nevertheless, in the overall populat ion of oil refinery workers potentially exposed to asbestos, many studies c learly show a definitely increased risk of mesothelioma, but no proven exce ss of lung cancer after comparison to the general population. Through the p resentation of new data and the re-appraisal of two recent and independent epidemiological studies conducted in Liguria, Italy, and Ontario, Canada, w e attempt to shed light on this apparently paradoxical finding. Methods Lung cancer mortality was studied among maintenance workers exposed to asbestos, and among two other subgroups of refinery employees: blue col lar and white collar workers. The comparison with blue collar workers was performed in order to take into account the role of healthy worker effect smoking habit, and the socioecon omic level. The comparison with white collar workers was performed to contr ol for other occupational lung carcinogens. Results and Conclusions Results reveal a consistency between the two studie s and show that 96-100% of the mesotheliomas and 42-49% of the lung tumors arising among maintenance workers were attributable to asbestos exposure. O ur new analysis, estimating two cases of asbestos-related lung cancer for e ach case of mesothelioma, confirms published findings on the magnitude of a sbestos-related tumors in oil refineries. (C) 2000 Wiley-Liss, Inc.