POTENTIALLY CARCINOGENIC ERIONITE IN ITALY: GEOLOGICAL OCCURRENCE AND RISK ASSESSMENT

Erionite is a fibrous mineral of the zeolite group mainly occurring as hydrothermal alteration product. The exposure of humans to erionite fibres has been unambiguously linked to malignant mesothelioma cases (Baris et al., 1978), and in vivo studies have demonstrated that erionite is significantly more tumorigenic than asbestos (Coffin et al., 1992). Recently, a growing concern has developed regarding the potential risks for environmental and occupational exposures to erionite in Turkey (Carbone et al., 2011), in the United States (Saini-Eidukat & Triplett, 2014), in Mexico (Ortega-Guerrero & Carrasco-Nùñez, 2014) and possibly in Iran (Ilgren et al., 2015). Newly researches on the identification of segregation of Fe(II) provide very important information for the understanding of the molecular mechanism/s inducing its strong carcinogenicity (Ballirano et al., 2015). Notwithstanding this, the relationships among mineralogical features and biological activity of erionite have not yet been fully understood and there are no systematic studies on the distribution of erionite or other similar fibrous zeolites in the environment. In Italy, erionite was reported in Sardinia and Veneto (Passaglia & Galli, 1974; Mattioli et al., 2016). Nevertheless, a systematic mapping of its distribution, the quantification of its presence in rocks and data about airborne fibers are still missing. Here we present mineralogical data of new erionite occurrences from Northern Italy, with a state of the art on the occurrence of erionite in Italy and some other potentially erionitebearing deposits. The studied erionite samples show prismatic to extremely fibrous habits and a variable tendency to break down in thin fibrils, which could be potentially pathogenic on inhalation. The chemical data acquired revealed variable amounts of Ca, Na, K and Mg as extra-framework cations, with small amounts of Fe. In Italy the knowledge of the epidemiology of mesothelioma linked to erionite is extremely scarce, and domestic cases from exposure to airborne erionite fibers are still to be inferred. Identifying the areas in Italy where erionite occurs naturally is a starting point for further specific studies on epidemiology, public health and natural hazards. An effective risk assessment in Italy will require coordinated actions from government agencies, local health authorities, Universities and research centers, in order to record the actual presence of fibrous zeolites, recognizing mineral species and quantifying their abundance in rock deposits.