Cadmium and lead distribution in sediment of the Bacina lakes (Croatia)

The Bacina lakes are small coastal inter-connected lakes in a karst area. The lakes are artificially connected to the hinterland Vrgorac field and the nearby sea in order to drain the field during heavy rains and floods. The storm water has changed the natural conditions in the lakes. In this paper the distribution of cadmium, lead and organic matter in the upper 10-cm sediment layer as well as granulometric composition were studied. In the fine-grained sediment carbonate particles prevail. Cadmium and lead concentrations in the sediment range from 0.21 to 1.37 mg/kg (dry weight - d.w.) and 2.3 to 30.2 mg/kg (d.w.), respectively, which are higher than those of both trace metals in the nearby source rocks. The main origin for cadmium is the Vrgorac field and its nearby rocks, while lead impact mainly originates from traffic along the nearby roads.