Geochemical investigation as a tool in the determination of the potential hazard for soil contamination (Kremna Basin, Serbia)

The geochemical composition of the soils and underlying sediments in the Kremna Basin was investigated. The aim was to assess whether the observed heavy metal concentrations in the soil samples represent geogenic or anthropogenic contamination. The second objective was to show that geochemical data of underlying sediments should be used as a tool in the determination of the potential hazard for soil contamination. For this purpose, the contents of As, Cr, Cu, Hg, Ni, Pb and Zn of soil samples were compared with standard values, a reference soil sample and local background values of the underlying sediments. The soil samples were unpolluted regarding the contents of As, Hg, Pb and Zn. All samples had higher contents of Cr and Ni, whereas three samples had higher contents of Cu than the limit standard values. Geochemical parameters showed that the higher concentrations of Cr, Cu and Ni in the soils could be attributed to geogenic impact. This conclusion was supported by the Chemical Proxy of Alteration and Chemical Index of Weathering values, which indicated intense weathering of the sediments. The obtained results showed that the Kremna area is under slight to moderate hazard if a land use change would occur, and proved the importance of the geochemical composition of underlying sediments in the interpretation of heavy metal pollution.