Investigation of heavy metal accumulation in Sapanca Lake sediment by using pollution indices

70 samples of surface sediments (from 0 to 5 cm depth) were seasonally taken between 2015 and 2017 from Sapanca Lake, the major drinking water source of Sakarya Province, Turkey. The scope of the study was to examine and assess the ecological risk of toxic metals such as Al, As, Ba, Cd, Co, Cr, Cu, Fe, Ni, Pb, Zn which are observed in the sediments collected from 10 different sample points of Sapanca Lake. Accumulation levels of toxic metals concentrations in the sediment samples were dissolved by using the microwave method and then measured with inductively coupled plasma atomic emission spectroscopy. The levels of toxic metal concentrations were identified as Fe > Al > Zn > Ba > Ni > Cr > As > Pb > Cu > Co > Cd, from highest to lowest, respectively. The quality of sediment is determined as "uncontaminated" according to The Sediment Quality Guidelines. Furthermore, sediment pollution is found not to be at toxic level. In addition, the sediments were evaluated by using following pollution indices: contamination factor, enrichment factor (EF) and geo-accumulation index. According to EF pollution index, higher rates for As and Cd indicate the presence of anthropogenic activities such as the consumption of fuel-oil in the industry and traffic.