Impacts of Pb-Zn mining on Lake Kalimanci and Human Health in Eastern Macedonia

Mining is very important economic activity. However, mining and related industries presents the main threat for environment. Pollution with heavy metals is a significant problem in Eastern Republic of Macedonia. In year 2003 great environmental disaster happened near small town Makedonska Kamenica, when the Sasa tailings dam collapsed and caused an intensive flow of mining waste material through Kamenica River valley and was discharged into Lake Klaimanci. Water from lake is used for irrigation, thus, the pollution assessment of the Lake Kalimanci sediments was made. The major, trace and rare earth element contamination in surficial lake sediments was studied to assess the effects of metalliferous mining activities. The mean concentrations of major elements [wt %] Si 23.5, Al 7.9, Fe 6.6, Mg 1.3, Ca 3.8, Na 1.1, K 2.3, Ti 0.4, P 0.2, Mn 0.6 and trace elements ranged within: Mo 1.0-4.6 mg kg-1, Cu 144.4-1162 mg kg-1, Pb 1874-16300 mg kg-1, Zn 2944-20900 mg kg-1, Ni 21.7-79.3 mg kg-1, Cd 16.5-136 mg kg-1, Sb 0.6-3.6 mg kg-1, Bi 3.0-24,3 mg kg-1 and Ag 1.4-17.3 mg kg-1. Results of rare earth elements (REE) in surficial lake sediments indicated that are tightly related to the catchment geology. The results of the sequential extraction procedure revealed the majority (Cd, Zn, Pb, Ni, Cu and Cd) of investigated toxic metals and all REEs to be strongly bonded to the exchangeable fraction and the rest (As and Mo) to the oxidizable fraction. Regarding to results is evident that heavy metals and REEs are highly bioavailable for living organisms and can seriously affect human health.