Bioavailability of arsenic in two Italian industrial contaminated soils

In the present work, the bioavailability of As in soils from two Italian dismissed mining and industrial sites respectively of Valle Anzasca (Piedmont) and Scarlino (Tuscany) is studied coupling biological assays and chemical analyses. The mineralogy and As total content were estimated respectively via XRPD and WDXRF. Sequential extractions coupled with TXRF were used to assess the potential bioaccessibility of As in soils. Mortality and reproduction tests, TXRF and μXRF were performed on earthworms (Eisenia andrei) exposed to contaminated soils in order to assess the eco-toxicity and the bioavailability of As. These preliminary results show that when As is associated with amorphous Fe-hydrous-oxides, the concentration of As in the coelomic fluids is directly related to the As concentration in soil. On the contrary, when As is associated with well crystallized Fe-hydrous-oxides, the concentration of As in the coelomic fluids is comparable with that observed in earthworm exposed to non-contaminated soils.