Influence of ancient mining settlements on Arsenic pollution inthe southwest of Tuscany

In this paper we describe the results of an extensive sampling of fluvial sediments collected from two very similar rivers and their affluents, which flows almost parallel from the “Colline Metallifere” towards the coastal wetlands: the Pecora river, which flows in the Scarlino plan and the Bruna river which flows in the Castiglion della Pescaia wetland. Important is to point out that the two twin rivers source and flows through identical geological and mineralogical territories, and both, until the middle 19th century, had as terminal point two similar coastal lake. Both these coastal lagoons underwent to similar filling processes, but their final destinations have been completely different. In fact, as reported above the Scarlino site was strongly industrialized conversely the Castiglion della Pescaia wetland was preserved as natural reservoir. From a comparative study of these two environments we were able to establish the extent of Arsenic natural background. Moreover we accumulated strong evidences of the importance of ancient mining and smelter sites in the formation of the environmental geochemistry as it is now.