[SENTIERI - Epidemiological study of residents in national priority contaminated sites: incidence of mesothelioma]

The purpose of SENTIERI-ReNaM Project is to describe mesothelioma incidence in the Italian National Priority Contaminated Sites (NPCSs). The present report deals with 39 NPCSs (20 in Northern Italy, 8 in Central Italy and 11 in Southern Italy). Asbestos is specifically mentioned in the regulatory acts of recognition for 10 NPCSs and it is the only agent that has determined environmental contamination in 3 of them (Casale Monferrato, Broni, and Bari). The timeframe of the study is 2000-2011 for 34 out of 39 sites. The corresponding reference periods for the sites of Latium, Campania, Umbria, and Bolzano Province are, respectively, 2001-2011, 2005-2011, and 2006-2011. Standardized Incidence Ratios (SIRs) for mesothelioma, with their corresponding 90% Confidence Intervals, have been estimated for all sites. The interpretation of the study findings has been based on anamnestic information made available by the Italian National Mesothelioma Registry (ReNaM), and completed thanks to knowledge derived from the international scientific literature. In men, mesothelioma incidence has shown excesses in 27/39 sites and defects in the remaining 12; in women, excesses have been reported in 20 sites, defects in 15, and no cases have been detected in the remaining 4 sites. The highest annual incidence rates have been observed in the sites characterized only by the presence of asbestos- cement factories (Broni and Casale Monferrato): respectively, 98.0 and 68.6 per 100,000 per year in men, 72.1 and 45.8 in women. Besides these two sites, the highest rates have been observed in the sites with naval shipyards: 13.2 in men and 2.5 in women. Excesses of mesothelioma incidence have been confirmed (with respect to previous observations) in the sites of Broni, Casale Monferrato, Balangero, and in the coastal areas of Trieste, La Spezia, Venice, and Leghorn. Balangero has been the major European chrysotile quarry, while the other sites are characterized by the presence of naval shipyards with demonstrated use of asbestos before it was banned in 1992. An excess of mesothelioma incidence has also been confirmed in the site of Biancavilla, characterized by the presence of the fluoro-edenite fibrous amphibole, classified as carcinogenic to humans by the International Agency for Research on Cancer (IARC). An increased incidence of mesothelioma was also observed in the areas where no direct use of asbestos had previously been documented, like Cengio and Saliceto (chemical industry), Falconara on Sea (oil refinery), and Litorale Domizio Flegreo and Agro Aversano (a large area including multiple hazardous waste dumping sites). These findings show that a relevant proportion of Italian mesothelioma cases is concentrated in NPCSs. About 1,500 extra cases of mesothelioma have been estimated in the overall series of 39 sites (2000-2011), corresponding to 125 extra cases per year. The excess has concerned the sites with manufacture of asbestos-cement products, but also the areas with asbestos quarries, naval shipyards, illegal hazardous waste dumping sites with asbestos-containing materials, petrochemical industries, refineries and steel plants. In some sites, particularly Casale Monferrato and Broni, analytical epidemiological studies have shown the causal role of not only occupational, but also environmental exposures, with special reference to paving of gardens and courtyards with asbestos-cement industry by-products. The main novelty generated by the collaborative SENTIERI-ReNaM Project concerns the detection of significant mesothelioma excesses not only in sites where asbestos is explicitly reported as a source of contamination, but also in a number of areas defined "of national interest" for environmental cleanup due to other sources of pollution. This confirms that the range of economic activities and working and living environments affected by asbestos exposure is very wide and it is not restricted to the industrial sectors characterized by the direct use of this material.