ANTHROPOGENIC AND GEOGENIC CONTAMINATION DUE TO HEAVY METALS IN THE VAST AREA OF VARI, ATTICA

Abstract

The purpose of this work was to investigate the soil heavy metal contamination of the area between Koropi and Vari, in Attica, Greece and to determine their anthropogenic or/and geogenic-lithogenic origin. Soil samples were taken from two different depths of 23 uncultivated sampling sites. Determined heavy-metal concentrations ranged widely; mean values in several sites were elevated and much higher than the soil grand mean worldwide. The higher Co and Ni contamination was found in the lower soil depth (10-25cm), while for Cd, Zn, and Pb in the upper depth (0-10cm). These results, in connection with the performed Hierarchical Cluster Analysis and Principal Component Analysis, indicate that there are two contamination sources. The first, concerning Co-Ni, is a geogenic-lithogenic source and the second, concerning Zn-Cd and Pb, is considered as an anthropogenic source. Since in the study area there is no evidence of an existing anthropogenic source (e.g. an industry) and the parent material does not confirm and give reason for the elevated Zn, Cd and Pb contents, it could be concluded that this contamination was due to ancient metallurgical activities in the area.