Articles | Volume 11, issue 5
Research article
09 May 2011
Research article |  | 09 May 2011

Linking rock fabric to fibrous mineralisation: a basic tool for the asbestos hazard

G. Vignaroli, F. Rossetti, G. Belardi, and A. Billi

Abstract. In recent years, many studies have addressed the effect on human health caused by asbestos exposures. As asbestos is a group of fibrous minerals that mainly occurs in mafic and ultramafic rocks (ophiolitic sequences), a close relationship between asbestos occurrence and the geological history of host rocks should be expected. By reviewing the existing literature and presenting characteristic examples, it is proposed a direct correspondence exists between the presence of fibrous minerals in ophiolites and the rock fabric systematics due to the combined activity of deformation, metamorphism/metasomatism, and rock/fluid interaction. Understanding the geological factors that may be at the origin of the nucleation/growth of fibrous minerals constitutes a necessary requirement for developing a methodological and analytical procedure to evaluate asbestos hazard (AH) in the natural prototype (ophiolitic rocks). A parameterisation of the AH in function of the main geological processes that produce the rock fabric systematics in different tectonic/geodynamic settings is discussed. A geological multidisciplinary approach (based on geological-structural field evidence combined with textural, mineralogical, petrological, and geochemical investigations) is proposed as the prerequisite for the evaluation of AH in natural environments. This approach, in particular, can provide a robust basis to formulate a procedural protocol finalised to the mitigation of asbestos effects in environments where these effects are still a real threat.