Pollution profile, source identification, and risk assessments of persistent organic pollutants (POPs) and toxic elements in the sediments of one of the water supply areas (Sultanbahçedere lake) to Istanbul, Türkiye

Abstract

This study was done to comprehensively exhibit the pollution level of surface sediments taken from Sultanbahçedere dam lake in terms of some persistent organic pollutants (POPs) and toxic elements, to decide the possible sources of polycyclic aromatic hydrocarbons (PAHs), to perform the ecological and human health risk assessments, and to evaluate the pollution profile with the hierarchically clustered heatmap (HCHM) analysis and principal component analysis (PCA). Naphthalene, Benzo(b)fluoranthene, Fluoranthene, Pyrene for PAHs; p,p-DDE, p,p-DDD, alpha-HCH, p,p-DDT, Endrin for OCPs; hexa and hepta chlorinated congeners accounting for 50.63% and 28.44% for polychlorinated biphenyls (PCBs); 1234678-HpCDD, OCDD for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs); PCB 118, PCB 105, PCB 167 for dioxin like-PCBs (DL-PCBs) and Al, Fe, Ca for elements were predominant in almost all of the sediments with a few exceptions. S4 site, which is one of the mid-sites of reservoir, has high concentrations in most of these pollutants. According to PAH diagnostic analysis, PAHs in the surface sediments are mostly affected by pyrogenic sources. The concentrations of POPs do not pose any toxic risk to aquatic organisms according to sediment quality guideline (SQG) and the limit values of other countries accepted in the world. Also, since none of the elements exceeded the effect range median (ERM) values, they do not pose a significant toxic risk to aquatic organisms. There is no risk for non-carcinogenic and carcinogenic hazards both for children and for adults considering hazard quotient (HQ), hazard index (HI), and lifetime cancer risk (LCR) values of all pollutants.