Assessment of eco-toxicological and health risks of core sediment from İzmit Gulf, Marmara Sea, Türkiye

Abstract

A comprehensive geochemical study was carried out to evaluate the environmental and human health effects of metal pollution in the Gulf of İzmit. For this purpose, the toxic and ecological risk distributions of a sediment core collected from 156 m water depth were determined. The mean concentrations of the studied metals as mg/kg dry weight in the İzmit Gulf core sediments were found to be in the following order: Cr (150.3) > Zn (122.7) > Pb (48.3) > Cu (35) > As (28) > Co (19.7) > Cd (3.6). A Contamination Factor (CF), Pollution Load Index (PLI), and Geo-Accumulation Index (Igeo) were used to assess sediment pollution. Increased industrial and agricultural activities around the İzmit Gulf has caused contamination in metals concentration, such as Cu (CF = 1.2), Zn (CF = 1.7), and Pb (CF = 1.5). This finding showed that Cu, Zn, and Pb contamination levels in the inspected core samples were moderate. Additionally, mean PLI values (1.2) point to human-induced contamination in the Izmit Gulf. The adverse effects of toxic metals on the organisms living in benthic environments were determined according to the Sediment Quality Guidelines (SQGs). According to SQG, living is exposed to toxic effects in terms of Cr, As, and Cd. The impacts of these toxic metals on human health were investigated by the Hazard Index (HI) and Cumulative Cancer Risk (LCR) parameters. Adults are not at risk from HI-As, however children have a value greater than 1 and require attention. LCR is another risk factor for Cd in adults and Cd and Cr in children.