Occurrence of asbestiform minerals in the Pollino Massif (Southern Italy): Environmental and health implications

Asbestiform minerals are potentially toxic and harmful to health and the environment and, in recent years, several studies have been made on the presence of asbestiform minerals in the Pollino Massif, on the border between Lucania and Calabria regions (southern Italy). Moreover, these small fibers can be easily inhaled by humans causing serious health problems especially to the respiratory tract. The formation of asbestiform minerals is related to metamorphism and/or metasomatic alteration of the metamorphic rocks. The main asbestiform mineral phases which have been found in the Pollino Massif are tremolite and, for the first time, edenite and Magnesium-riebeckite. The observed asbestiform minerals found in the metamorphic rocks of the Pollino Massif are thus: i) tremolite, which is characterized by acicular, friable, fibrous, and elongated habitus and was found as intergrowth with fibrous antigorite and chrysotile. In the analyzed rocks, tremolite was found in veins associated with clinopyroxene porphyroclasts; ii) edenite, which is often associated with serpentine, diopside and calcite or occurs as 30 to 80 µm-long single crystals with a fibrous habit. The presence of edenite in the ophiolitic sequences is quite rare and testifies a medium to high metamorphism; iii) magnesium-riebeckite, a record of metamorphic events in blueschist facies, composed of prismatic, acicular crystals with a fibrous habit having length ≥ 5 µm and width < 3 µm with aspect ratio > 3:1. These mineralogical phases were analyzed and characterized using different analytical techniques such as X-ray fluorescence (XRF), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), electron probe micro analysis (EPMA) and X Ray Powder diffraction analysis (XRPD). The aim of this work is to create, for the first time, a geo-mineralogical map of the asbestiform minerals detected in these areas in order to evaluate their spatial distribution.