Elemental accumulation in the surficial sediment of Kesikköprü, Çubuk II and Asartepe Dam Lakes (Ankara) and potential sediment toxicity

In this study, Çubuk 2, Kesikköprü and Asartepe Dam Lake, were investigated. A total of 60 sediment samples were collected and the concentrations of 10 elements (Cu, Pb, Zn, Ni, Mn, Fe, Co, Cr, Al, As) were determined. The obtained findings were compared to the limit values for the sediment quality guidelines (SQGs) and were investigated using sediment assessment methods. The results indicate that the values for SQGs revealed that the concentrations of Ni and As should be emphasised. Toxic unit (TU) values showed that As and Ni together constitute 69.95–80.09% of the total toxic effect alone for all lakes. In addition, the Contamination factor (Cf) and Enrichment factor (EF) detected the concentration of As for Kesikköprü Dam Lake as being at a medium and higher accumulation levels, although the Geoaccumulation index (Igeo) detected that As leads to contamination below the medium level. When the total element accumulation was evaluated, no risk was detected for the lakes. Cluster analysis (CA) revealed quite different elemental profiles for 3 lakes. The strongest correlation between the elements was observed for Cu-Ni (r = 0.942) in Çubuk 2, whereas Çubuk 2 was the lake with the highest seasonal elemental variation among the lakes investigated.