Morphological and chemical analysis of tremolite related to natural asbestos in the road paving

Abstract

Tremolite group minerals could be present in the aggregate used as filler in the mix asphalt floor in the road surfaces and are subject to wear for vehicular traffic and materials ageing. Dust produced by the degradation of asphalt surfaces can disperse tremolite group minerals present in road paving causing exposure by asbestos fiber to an increasing number of people and animals. In recent years, attention has been focused on naturally occurring asbestos (NOA) as the greatest frequency of lung cancer has been observed in environments characterized by rocks and soils rich in Tremolite that characterize asbestos minerals. Asphalt samples object of this study were collected in a motorway segment of the Lombardia Region (north of Italy) for an exposure assessment research on road paving workers. The evaluation was performed using a metrological approach based on petrographic and mineralogical analyses in order to reduce the epidemiologic risks and to define the best treatment strategies on waste management with sustainable costs in fulfilment of Council Directive 67/548/EEC (1967) and EC Regulation 1272/ 2008 (2008) (Paglietti et al., 2016). The fibers are generally not broken down to other compounds in the environment, but asbestos hazard could be related to the occurrence of tremolite fiber in road paving arises when natural weathering processes (e.g., erosion) or human activities (e.g., continuous passage of motorized vehicles) separate and break down the fibers, which could be lost into the environment as airborne and easily penetrate into the human respiratory tract (Punturo et al., 2019). Despite this, this work is not an epidemiological risk analysis but obtained data could be useful to other specialists to define the exposure risks.