Geochemistry of Cd in Sardinia: regional scale studies

For more than thirty years, the DICAAR researchers have been leading studies in Sardinia, whose territory has along history of mining exploitation, begun before the Bronze Age. Through the sampling of several environmental media supports and their analytical data, this research activity led to the creation of a large database, populated by thousands of data concerning soils, rocks and stream sediments. Sampling and analytic surveying are currently finished. A new phase is starting up to transform the stream sediment database, which was previously used for the aim of industrial mining, as a new source of environmental information. The deep experience in mining, with the help of modern technology, allowed to refine techniques for the detection of ore deposits up to make them extremely sensitive. By transferring these experiences in the environmental field, it is possible to identify and to delimit areas presenting pollution and/or high values of harmful elements; moreover, it also allows to detect the background in studied lithologies, even when significantly hidden by anthropic activity. Geochemical data were geo-referenced with a geographic information system (GIS) and now are available for further studies. In the present study, the geochemical data of Cd was analyzed in order to evaluate the Cd contents in Sardinian soils, in relation to the Italian law limits.