Metal pollution status and ecological risk assessment in marine sediments of the inner Izmit Bay

Abstract Metal concentrations (Al, Fe, As, Cu, Cr, Cd, Ni, Pb, Zn, and Hg) were determined in the surface sediments of the polluted parts of the inner Izmit Bay (Marmara Sea, Turkey). The dataset was established from 25 sampling points to evaluate contamination, toxicity, and ecological risk levels of metals in the inner bay, using various sediment quality guidelines (SQGs) and contamination assessment methods. The results showed that the concentrations of Zn, Cu, Cr, and Ni exceeded the background levels determined for the Marmara Sea by a factor of 1.2 - 4 whereas the total concentrations of As, Cd, and Pb were comparable with the background values of surface sediments from the less polluted areas. The SQGs analysis of Zn data indicated that surface sediments had been contaminated at all of the observed points of the inner bay. Locally, surface sediments of the northern entrance of the inner bay are more polluted than the other regions of the bay, presumably due to anticlockwise surface current system prevailing in the region.