Potentially Toxic Elements and Pb Isotopes in Mine-Draining Meža River Catchment (NE Slovenia)

Abstract

In the present study it was observed that Pb, Zn, Cd and As are still present at elevated concentrations in the environment of the upper Meža Valley. In particular, the concentrations of Pb indicate possible new sources have emerged. The main objective of this study was to determine the Pb isotope composition in both the water and the sediments (fractions < 0.150 and <0.063 mm) from the Meža River and its tributaries for the first time and then use them as identifiers of Pb pollution sources. In addition, by calculating the PEC-Q values, the potential hazard of the present concentrations of Pb, Zn, Cd and As to the river environment was evaluated. The results showed elevated Pb and Zn concentrations in the water and sediments at the majority of sampling sites. In general, higher concentrations of Pb, Cd and As were determined in the <0.063 mm fraction, while Zn was higher in the <0.150 mm fraction. The isotope composition of Pb in both fractions differed slightly, indicating an additional Pb source.