Cancer frequency and asbestos exposure in the asbestos-cement industry

The asbestos-cement industry has been the largest user of asbestos fibres in Italy, as elsewhere in the world. In this review we present a summary of studies on cancer occurrence in asbestos-cement workers and on cancer risk associated with domestic and environmental exposure. The largest Italian asbestos-cement factory was located in Casale Monferrato and was in operation between 1907 and 1986. The cohort study included 2,657 men and 777 women. Follow-up was extended until 2003. Mortality was increased in both sexes for all causes (overall 1809 observed vs 1330.4 expected; p < 0.01), pleural (105 vs 3.6; p < 0.01) and peritoneal (52 vs 2.6; p < 0.01) malignancies, lung cancer (249 vs 103.6; p < 0.01) and asbestosis (186 vs 0.4; p < 0.01). Similar results on workers in the asbestos-cement industry have been observed in several studies in Italy, as all over the world. In Casale Monferrato we also investigated the risk of pleural mesothelioma after domestic and environmental exposure. The SMR for pleural malignancy in wives of asbestos-cement workers was 1200, based on 6 cases occurring in 1950-1993. A case-control study showed strong inverse association between distance of dwelling from the factory and risk of mesothelioma. Evidence from the literature is limited to a few studies; there is however a general consensus on the increased risk of mesothelioma for subjects with domestic and environmental exposure. We wish to emphasize that Casale Monferrato is not a unique situation, and that other areas in Italy show increased occurrence of mesothelioma following occupational, domestic and environmental exposure. These areas ought to be studied as thoroughly as Casale Monferrato.