Heavy metals in seawater and sediments from the northern Liaodong Bay of China: Levels, distribution and potential risks

This study investigated seasonal variations, spatial distributions, levels, and potential ecological risks of heavy metals in surface seawater and sediments of the northern Liaodong Bay of China. The concentrations of cadmium (Cd), lead (Pb), mercury (Hg), arsenic (As), copper (Cu), and zinc (Zn) were 0.66, 3.98, 0.14, 5.46, 2.86, and 17.76 μg/L in seawater, and 0.34, 18.77, 0.10, 10.24, 18.90, and 77.22 mg/kg in sediments. The concentrations of Pb, Zn, and As in seawater and sediments exhibited significant seasonal pattern, whereas that of Cd did not vary statistically across seasons. High levels of Hg, Cd, and Zn were found in the western part of Xiaoling River mouth, and As showed a high level in Xiaoling River mouth and the western part of Daling River mouth. Generally, Pb, Cd, and Hg mainly dominate the metal pollution in the investigated area. Sediments from all sampling sites were characterized by low to medium ecotoxicological risks and occasionally negative toxic effects could occur on the benthic infauna and ecosystems in the northern Liaodong Bay.