Impact of Pb-Zn mining activity on surfcial sediments of Lake Kalimanci (FYR Macedonia)

Abstract

The activities of the Sasa mine have led to industrial discharge being released into Lake Kalimanci since the beginning ofmining activity in 1954. For this reason, an ecological risk assessment is urgently required. In the present study, surfcial lake sedimentswere analyzed using inductively coupled plasma mass spectrometry (ICP-MS), with all geochemistry data processed using Statistica 8.In order to assess the environmental pollution status, 2 environmental factors were established, while for the determination of chemicalfractionation of toxic metals a sequential extraction procedure was carried out. Concentrations of As, Mo, Zn, Ni, Co, Pb, Cd, and Cu insurfcial Lake Kalimanci sediments were in the ranges of 58.6 77.2, 2.30 4.60, 7056 20,900, 47.4 79.3, 18.8 25.3, 4863 16,300, 46.8136, and 328 1162 mg/kg, respectively. Based on values of the enrichment factor and geoaccumulation index, the surfcial sediment ofLake Kalimanci is strongly polluted in terms of most of the examined metals. The results of the sequential extraction procedure revealedthe majority of the investigated toxic metals (Zn, Pb, Ni, Cu, and Cd) to be strongly bonded to the exchangeable fraction and the rest(As and Mo) to the oxidizable fraction. Te geochemistry, environmental factor values, and toxic metal extraction characteristics of LakeKalimanci sediments represent a serious environmental risk for an extensive area.