Formational anomalies versus mining pollution: geochemical risk maps of Sardinia, Italy

In two recent papers by De Vivo and co-workers, multielement geochemical maps of the island of Sardinia have been compiled using 16,890 stream sediment samples collected from 1972 to 1975 by the Ente Minerario Sardo (EMS). For the compilation of the geochemical maps reported here, these EMS samples have been integrated with an additional 9260 stream sediment samples from 7 Conventions, agreed upon in the 1980's by the Italian Ministry of Industry and EMS, and also include another 185 stream sediment samples from the sampling of 1972-75. From this combined dataset, new multielement geochemical maps (51 elements) of Sardinia have been produced, covering a surface of about 12,000 km(2) with a nominal density of 1 sample per 0.5 km(2). These maps are published in an atlas of the Italy Geological Survey (Servizio Geologico d'Italia). This paper reports and discusses the results obtained by mapping the combinations of chemically compatible elements tin groups of three), by means of a GIS (Ari/lnfo), and the results of geochemical risk maps. For this compilation, the distribution of regional elements has been reclassified, using the known intervention criteria for agricultural, residential/recreational and commercial/industrial land use as thresholds. (C) 1998 Elsevier Science B.V. All rights reserved.