Significant clusters in female population
Significant clusters in female population are rarer than those found among men. We found significant increased female clusters for MM and MPM, in correspondence to shipyards (Monfalcone, Livorno, Napoli), asbestos-cement plants (Casale Monferrato, Broni, Bari, and some towns of Reggio Emilia and Modena Provinces), complex industrial areas, like Taranto, with the presence of steel industry, shipyards, oil refineries. Considering the typical work-force in these activities (mainly males), the female excess in these areas, could be due to household or environmental exposures. The excesses found in female population of Sarnico (Lombardy) and Grugliasco (Piedmont) were already considered in previous analyses, and attributed to the presence of textile industries. Asbestos exposure and MM cases among workers of non-asbestos textile industry of Sarnico and significant excesses of mortality risk for asbestos-related diseases among workers, particularly in women, of asbestos-textile plant of Grugliasco were documented [30,31]. Residual asbestos lung fibres in MPM cases non-asbestos textile industries workers were reported . The presence, until the 1990s, of textile machines equipped with asbestos-lined mechanical brakes and air widespread inside presence of the dust produced by rapid wear of the linings was documented . Non-asbestos textile sector was identified as causing asbestos exposure in more than 40% of both pleural and peritoneal MM female cases of occupational origin in Italy. Gender ratio (W/M) of MM cases in textile industries with or without direct use of asbestos in the industrial Fulvestrant (ICI 182,780) was reported to be higher than one . The excesses of mortality for MM and MPM observed in both female and male populations living in Biancavilla, a Sicilian town at the slopes of Etna Volcano, deserve particular mention, because of the presence of naturally occurring fluoro-edenitic fibres in a stone quarry localized near to the urban centre of the town. These fibres were classified as carcinogenic , on the basis of epidemiological investigations performed in Biancavilla , supported by in vivo and in vitro studies [, , ]. In Italy, asbestos cement, rolling-stock production and maintenance, shipbuilding, dockyard and harbour workers accounted for a large fraction of asbestos-exposed workers in Italy . In the present analysis, for the first time since the beginning of mesothelioma mortality epidemiological surveillance, a significant cluster of mesothelioma mortality was found in the male population of La Maddalena, an island close to Sardinia, where an Italian Navy shipyard is located. Furthermore, our results confirm mesothelioma mortality risk in other areas with important shipyards, where high mesothelioma risk have yet been observed [39,40]. The presence of high concentrations of asbestos fibres and bodies in lung tissue of shipbuilding workers was documented in a large cohort from an important Italian shipyard, where asbestos and asbestos-containing material were used, until mid ‘80 s; in the same cohort, high percentage of cases of asbestos-related diseases was diagnosed, among workers of several job types . In the present paper, the area around this harbour (Monfalcone) showed significant increased mortality risk, in both SMRs and clustering analyses. Another finding of the present study concerns Procida, a small island in the Gulf of Naples, where a large proportion of the male workforce is employed as sailors in merchant ships. The risk of mesothelioma in ship-workers, including military servicemen, has been documented in some countries [42,43]. Considering the widespread inside presence of asbestos fibres and the confined spaces in the vessels, the asbestos exposure of a large number of sailors, in addition to shipyard workers, have been hypothesized . In addition to the areas that have above been mentioned, significant clusters were detected in areas, not previously highlighted, where ad hoc studies should be performed in order to check asbestos-exposure sources: the areas around an industry of production of turbines (Legnano), chemical plants (Mira, Cengio and Rosignano Marittima) and steel industries (Terni and Dalmine). In the study of mesothelioma incidence in Italian contaminated sites an excess was detected among men living in Cengio, particularly due to occupational exposure; statistically significant excesses were not found in Terni .