Fraction distribution and risk assessment of heavy metals and trace elements in sediments of Lake Uluabat.

To examine the status and risk of heavy metal pollution, the distribution of As, Cd, Cr, Ni, and Pb in the sediment of Lake Uluabat was characterized. The present study used a four-stage method to assess the ecotoxicological effects of the heavy metal and trace elements fractions in the sediment of Lake Uluabat. Total Cr and Ni concentrations in the sediment were determined to have exceeded the severe effect level (SEL) limit values. The percentages of the variable fractions of Cr and Ni were below 10%. Because of this reason, they were not defined to have a high risk. The relationships among the physicochemical parameters, heavy metals and trace elements in water and sediment were determined statistically. Pb, Cd, and As in the water were found in relation with some of the fractions. Moreover, it was thought that the amounts of the elements of As releasing into the water might be increased due to their relations with the physicochemical parameters.