[The epidemiologic surveillance of malignant mesothelioma in the Lower Iseo Lake area]

Starting from an hospital observation of the mesotheliomas cluster in women living in a lakeside area (Iseo lake, Northern Italy), an epidemiological surveillance of this tumour was performed by the local occupational health service. This cluster wasn't notified, in spite of the relevant number of factories producing asbestos textile materials in this area. From 1977 to august 2006, 45 cases of mesothelioma were detected among the workers of 3 textile industries located in 3 little villages: 14 cases occurred working crocidolite and chrysotile rope and gasket; 20 cases in a textile factory producing cotton garments, that was adjacent to and polluted by the farmer and were asbestos insulation and blankets used for fireproofing are present; 11 cases occurred among women working in silk factories. The mesothelioma cases occurred in the same period in this area, which constituted the recruitment area of the people working in the 3 textile plants (11 villages, about 43,000 inhabitants), are 55.93% of which had been occupationally exposed to asbestos. Out of the dockyard and the asbestos-cement industries, this frequency of occupational exposed workers is the highest never observed in Italy. The majority of the cases (66%) occurred among women working in the textile factories. In a women, producing asbestos textile materials and suffered form peritoneal mesothelioma and pleural plaques, the analysis (by SEM) of asbestos fibre lung burden show 286 million fibres x gr. of dry tissue. Between the 42 mesothelioma cases occurring in the population of the 3 villages where the textile plants was located, we observed only one case with possible environmental exposure to asbestos: a gardener of the village where the manufacturing asbestos ropes and gasket plant is present. In the silk factories, asbestos exposure was probable because of the presence of asbestos insulated pipes. The female pleural mesothelioma standard incidence observed in this area (6.8 x 100,000, 1977-2005) is the highest never estimate in Italy. The epidemiological surveillance of the mesothelioma appear essential to identify cases unreported and allow the collection of information useful to understand clearly the asbestos exposure effects on health's workers and to estimate the tumour incidence in the population.