Environmental implications related to natural asbestos occurrences in the ophiolites of the Gimigliano-Mount Reventino Unit (Calabria, Southern Italy)

Metabasites and serpentinites of the ophiolitic sequence of the Gimigliano-Mount Reventino Unit (Calabria, southern Italy), also known as greenstones, are employed and marketed for building and ornamental purposes since prehistorical times. The main topic of our research focuses on the occurrence, within the above lithotypes, of asbestiform minerals that may be potentially harmful for human health. A detailed mineralogical and petrographic characterization by means of Polarized Light Microscopy (PLM), X-Ray Powder Diffractometry (XRPD), Scanning Electron Microscopy combined with Energy-Dispersive Spectrometry (SEM/EDS), and Thermo Gravimetry together with Differential Scanning Calorimetry (TG/DSC) pointed out as asbestiform minerals may occur in outcrops as well as in quarries located in surroundings of Mount Reventino. Indeed, tremolite resulted to be the main constituent among the asbestos minerals contained in metabasites, followed by actinolite; moreover, other amphiboles (not regulated by the Directive 2003/18/EC of the European Parliament and of the European Council of 27th March 2003) detected are crossite, glaucophane, hornblende and gedrite. As far as serpentinites, chrysotile is the dominant asbestos phase. Obtained results hold environmental implications, since they can be used in order to take decisions for the realization of health protecting measures during human activities such as road construction and quarry excavations and may also provide new data for the compulsory Italian mapping of natural sites that are characterized by the presence of the asbestos commonly known as NOA (Naturally Occurring Asbestos).