Heavy Metals Fractionation in Agricultural Soils of Pb/Zn Mining Region and Their Transfer to Selected Vegetables

Abstract

Improved understanding of the relationships between heavy metals fractionation in agricultural soils and biological uptake could be obtained by analysing samples of biota in parallel with sequential extraction of their grown media. The overall goals of this study were to identify the characteristics of metal fractions and their bioavailability to maize and potato plants in the agricultural land of the Ibar River in southern Serbia and northern Kosovo. The concentrations of Pb, Zn, Cd, Ni, Cr and Cu in soil and vegetable samples were determined by the ICP-OES method. Pb/Zn production and industrial waste disposal significantly increased the pseudo-total concentrations of heavy metals in the soil together with their mobile and potentially bioavailable amounts. The Pb concentrations in the vegetable samples were generally above the EU maximum permitted concentrations in foodstuffs. However, the concentrations of Zn, Ni, Cr and Cu in the vegetables were below the critical levels. The results of the present study indicated that the intensive industrial production of Pb/Zn over the years and permanent pollution were responsible for the environmental contamination by heavy metals in the study area, particularly by Pb and Zn. The quantity of the mobile and potentially bioavailable heavy metals in the studied soils threatens the quality of Zea mays L. and Solanum tuberosum L. crops, with a real risk that these elements could enter the food chain.