Ophiolitic outcrops, naturally occurring asbestos exposure and mortality risk from malignant mesothelioma in Calabria (Southern Italy)

Abstract

ObjectivesNaturally occurring asbestos from ophiolitic outcrops can pose a health risk to the resident population. Some studies have documented this risk of exposure in many areas around the world. The aim of the study is to estimate the possible impact on health caused by asbestos outcrops present in some areas of Calabria, a region of southern Italy. Study designThe design of the study is observational and uses routinely collected data on employment, compensations and mortality. MethodsData from archives of mortality in the period 2005–2015 were selected. Standardized mortality ratio (SMR) for malignant mesothelioma (MM) by municipalities of residence with reference to the regional population was estimated assuming a Poisson distribution of the data. Administrative archives of companies' employment records and occupational disease compensation data were used to exclude occupational origin cases. ResultsA total of 163 cases of MM were identified. Statistically significant excess risks (P-value <0.05) were observed for several municipalities, some of which were located in areas where asbestos outcrops had previously been identified. Significant SMRs vary between 44.0 and 5.2. The mean age at death in the areas at risk of ophiolitic outcrops ranges from 65.4 to 77.1 years, and the gender ratio (male/female) ranges from 0.66 to 1.3. ConclusionsMonitoring of areas most involved in the risk of environmental contamination from ophiolitic outcrops is highly suggested. Full implementation of the local MM surveillance system is strongly encouraged. Further investigations are recommended to specifically identify the cause of exposure and confirm the hypothesis of a causal association with asbestos naturally occurring in these risk areas.