Assessment of the heavy metal contamination in the surfcial sediments of Lake Kalimanci (Macedonia): a preliminary study

A major disaster happened in the eastern Macedonia (Europe), when part of the Sasa Mine tailings dam collapsed and caused an intensive fow of tailings material which ended up in Lake Kalimanci. The aim of this study was to assess the heavy metal contamination (Ag, As, Cd, Cu, Mo, Pb, Sb and Zn) of the surfcial sediments from Lake Kalimanci. The pollution status of the sediments was evaluated by application of two environmental indices: the enrichment factor and a geoaccumulation index. The enrichment factor values (Cd 735; Pb 386; Zn 151; Ag 146; As 48; Cu 21; Sb 10 and Mo 2) revealed extremely elevated heavy metal concentrations in the investigated samples. The geoaccumulation index indicated that surf-cial sediments of Lake Kalimanci can be treated as moderately to strongly polluted with Pb and Cd, moderately polluted with Zn and Ag, unpolluted to moderately polluted with Cu and As and unpolluted with Mo and Sb