Spatial and temporal assessment of cadmium and chromium contamination in soils in the Karditsa region (Central Greece)

In this work, we aimed at monitoring Cd and Cr levels in surface soils in the Karditsa region (Central Greece). Soil samples were obtained throughout 3 years (2010 to 2012) and analyzed for extractable (DTPA) and for "pseudo"-total concentrations (aqua regia) of Cd and Cr. The temporal variability, recorded twice per year, was also assessed. Significant spatial variability was recorded and illustrated by the respective thematic maps created using geostatistics, with the use of ordinary kriging. We found a possible geochemical connection and interactions between the two studied metals that indicated common lithogenic origin, while Cd was found further enriched due to likely applied phosphate fertilizers over long periods of time. We conclude that although the mapping of soil properties and metal contents is a useful tool when initially visiting an area, further in-depth studies should be conducted; such studies should address issues related to bioavailability of soil pools that may be linked to plant concentrations and possible risks of metals being transferred to plants or even humans.