Arsenic pollution in the southwest of Tuscany: monitoring of Cornia catchment basin

The territory of Colline Metallifere, in SW Tuscany, is characterized by the presence of strong arsenic anomalies. Some hypotheses, formulated in the last 20years, based on geological and mineralogical factors have failed to explain the peculiar distribution of this toxic element in soil, fluvial sediments and groundwater. Our research group has been studying for four years the problem of arsenic pollution in this district to investigate the origin and the mechanism of Asdiffusion in the environment. In particular we started a comparative study basedon the extensive sampling of the stream sediments of the main waterways of Colline Metallifere (Pecora, Bruna and Cornia and their tributaries). In this work we focused our attention on the stream sediments and the soil of the Cornia basin. The comparative analysis of Cornia and the other rivers of the area,together with the investigation of historical series of data, provided importantinformation about the origin of contamination of the territory and the impact of ancient mining settlements on this phenomenon.