Distribution and environmental risk evaluation of heavy metal in core sediments from Lake Çıldır (NE Turkey).

This study examined the vertical distribution of heavy metals in core sediments taken from Lake Çıldır, Turkey, and their potential ecological risks together with organic carbon content and chlorophyll degradation products. Samples were collected from six sampling stations determined along two main transections aligned in north-south and east-west directions. The enrichment (EF) and contamination factor (CF), potential ecological risk (PER) index, and pollution load index (PLI) were calculated from the obtained results. For the elements Pb, As, and Cd, a moderate level of contamination was detected, whereas a moderate-to-high concentration level was obtained for Mn. The highest contamination level was found for Hg. A pollutant accumulation exists particularly in the surface sediments. Cd and Hg are the only two metals considered to be a potential risk factor in the lake.