Thallium pollution in water, soils and plants from a past-mining site of Tuscany: Sources, transfer processes and toxicity

This paper provides a case-study analysis on a thallium contamination related to the past activity in the dismissed mining sites of Monte Arsiccio and Pollone (Lucca Province, Tuscany, Italy). This site has received a lively public attention in recent times, after the finding of thallium at concentration of concern in drinkable waters, far exceeding the U.S. EPA threshold of 2 mu g/L. Already published studies, plus original data, focusing on the different aspects of this case study are here reviewed highlighting how past-mine wastes can affect a whole eco-system, potentially causing adverse health effects in the population living in the area via environmental exposure. After a brief introduction on the mining activity in Tuscany (Section 1), the paper focuses on the geochemical processes behind the release of thallium in the area subject of the study (Sections 2-4), the status of its contamination in different ecological compartments (Sections 5-9) and the exposure of the local inhabitants (Section 10). As final remarks, considerations about possible health impacts are presented. The aim is to contribute to the proactive detection of environmental threats mainly related to thallium hazard and past mining activities, in order to prevent negative impacts to the ecosystem and human health, and to contribute in planning mitigation requirements.