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

Abstract

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 (A H ) in the natural prototype (ophiolitic rocks). A parameterisation of the A H 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 A H 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.

Naturally Occurring Asbestos (NOA) in Granitoid Rocks, A Case Study from Sardinia (Italy)

“…The occurrence in nature of fibrous amphiboles (anthophyllite, actinolite, tremolite, crocidolite and amosite), and chrysotile, i.e., the six silicate minerals defined by the existing regulation as "asbestos" (e.g., [1][2][3][4][5][6][7][8][9]) is increasingly attracting attention in environmental hazard evaluation [1,10]. In natural environments, the NOA (natural occurring asbestos) hazard arises when physical/mechanical processes produce airborne fibers that, due to their low density and small size, can be widely dispersed and, therefore, contaminate the atmosphere and water supplies e.g., [2,3] (Figure 1). Figure 1.…”

Experimental Deployment of Microbial Mineral Carbonation at an Asbestos Mine: Potential Applications to Carbon Storage and Tailings Stabilization

“…Mining activity has ceased at many of these locations; however, megatons of tailings containing asbestiform minerals remain, posing a threat to the health of nearby residents [24] and polluting natural waterways [22]. Although the mineralogy of the tailings at derelict asbestos mines is well characterized [8,21,25], and asbestos mineral hazard-assessment guidelines are available [26,27], the challenge of remediating this industrial waste remains unsolved. Targeting asbestos mine tailings as a feedstock for mineral carbonation has the potential to aid in tailings containment and remediation with the added value of offsetting carbon emissions.…”

Treatment and recovery of contaminated railway ballast

“…In addition to anthropic pollution, a further release of hazardous compounds from ballast can be also attributed to the presence of naturally occurring species such as asbestos materials from ophiolite [5]. Polluted ballast gravel may easily transfer pollutants by rainfall, thus causing pollution of soil and groundwater.…”