Italian MM mortality rates in men and in women
Italian MM mortality rates (3.65/100,000 in men and 1.09/100,000 in women) are similar to the highest rates of MM incidence reported in industrialized countries . The Regions with mortality rates higher than the national ones are also those with the higher number of main industrial settlements, exception made for Valle d’Aosta, a mountainous region in the Western Alps. The latter presents 42 deaths for MM (2.65/100,000 inhabitants) and, among those, 20 deaths for MPM (2.21/100,000 inhabitants); municipal SMRs and clusters were not detected in statistically significant increase in this Region. The ReNaM reported 39 incident cases of MM in Valle d’Aosta . In this Region, the presence of chrysotile and tremolite asbestos minerals in mines of Crètaz and Emarese was documented . Both mines were among the main mines in Italy: the first one, active until 1979, for the magnetite and the second one, active until 1968, for the chrysotile . Temporal trend of rates showed that the mortality for all malignant mesothelioma, and especially for pleural mesothelioma, is rising in males. This is in agreement with the prediction of a peak in Italy, with about 800 mesothelioma annual male deaths, in the period 2012–2024 . The long latency period of the disease, with the past or on-going presence of asbestos exposure sources even after the ban , may explain the observed raising trend of MM mortality. In Italy, the median latency period was estimated in 48 years (range: 4–89 years), on the basis of 11,434 occupational asbestos exposed cases . Previously, the latency period was reported shorter (43.4 years) in occupational than in environmentally exposed cases (48 years) . Subsequently, the anticipation of mesothelioma occurrence, but not necessarily abbreviation of latency time, was associated with cumulative exposure . A recent pooled cohort study, that includes a total of 51,801 subjects, support the LY 379268 that the increase in risk of pleural malignancies according to a power of the Time Since First Exposure (TSFE) flattens out after about 40 years and may even start to decrease. Instead, peritoneal malignant neoplasm risk increases over five decades of TSFE in men and over all the observational time in women . Out of the 247 municipalities detected with significant exceeded SMR for MM, 59 did not show significant excess of MPM mortality. A comprehensive presentation of all Italian municipalities with an excess mortality from MPM was recently published in the frame of the Third National Asbestos Conference . In addressing the various areas of the country where an excess is reported, it is important to search for possible clues considering both previous occupational exposures that do not exist anymore (e.g. those related to asbestos mining and manufacture of asbestos containing products) and workplaces with remarkable quantities of in-place asbestos sources due to the use of this material as an insulating agent (e.g. in steel plants, oil refineries and petrochemical plants). Because of the long latency time of mesothelioma, some spatial clusters are strongly evident in areas where asbestos-cement was produced, both after successful environmental remediation (e.g. Casale Monferrato) or in situations where clean-up activities are still in progress (e.g. Broni, Bari). Even if SMR analysis could be affected by random effects, some signals deserve specific attention. In this context, the excess found in the male population of Balangero, based on 3 cases (SMR = 309, 95%CI:105-910), with the woman died for MPM, is of particular concern. In Balangero an open-air mine of chrysotile had been operating since 1917–1990. MM cases among workers of the mine and in people exposed to chrysotile in Balangero have been registered , as well as an excess of mortality for pleural cancers among the miners . In male population living in Balangero an excess of MM occurrence was found, on the basis of 5 cases, of which two defined with environmental exposure due to the residence close the quarry . These findings are worth mentioning in light of the persistent false belief of a lack of chrysotile carcinogenic still claimed in some countries .