Chrysotile asbestos in serpentinite quarries: a case study in Valmalenco, Central Alps, Northern Italy

摘要: The Valmalenco serpentinite (Central Alps, Northern Italy) is marketed worldwide as dimension and decorative stone. However, the same area was once subject to chrysotile asbestos mining, from XIX century until 1975. Asbestos a well-known carcinogen, there possibility of releasing fibres during quarrying, subsequently exposing workers. From 2004 2011, extensive sampling monitoring quarry fronts, veins, commercial stones airborne carried out. Massive rock vein samples were analyzed by combined use optical microscopy, X-ray powder diffraction (XRPD) quantitative electron microscopy (SEM). concentrated almost exclusively in discrete horizons, that coincide with main discontinuities mass. Commercial without fractures veins are practically free, whereas slight contamination (sometimes exceeding 1000 ppm threshold) close hydrothermal selvages. Quarry floors always quite contaminated “beards” detached surface blocks. concentrations (PCM SEM) distributed over wide range, mostly below occupational exposure limit 0.1 f ml−1. Concentrations at property border or closest villages environmental 0.002 extreme thinness fibrils produced quarrying activities, abundance pseudo-fibrous antigorite cleavage fragments proved SEM-EDS analytical procedure be most suitable. It crucial importance avoid interception remove all visible extracted blocks, before any further processing.