Distribution and pollution assessment of heavy metals in sediments from typical areas in the Bohai Sea
环渤海典型海域潮间带沉积物中重金属分布特征及污染评价

The content of heavy metals in sediments from 11 sampling sites in the intertidal zones around the Bohai Sea was examined. Results show that the average content of Cu, Cr, Zn, As, Cd, Pb is 14.92, 31.73, 73.68, 11.34, 0.448, 21.94 mg/kg, respectively. The content of Cu, Cr, Zn, As is relatively low and the content of Cd, Pb is at moderate level, compared to typical estuaries and gulves in China. The general content distribution of individual elements in the three bays is as following: Liaodong bay > Bohai bay > Laizhou bay. Correlation analysis indicates that Cr, Cu, Zn, Cd, and Pb may have the similar source but As may have different source . The evaluation by Geoaccumulation Index indicates that Cr, Cu, Zn, and As reach the clean grade; Pb is slightly polluted; Cd is slightly pollluted in dominant areas but in some parts it is moderately or seriously polluted.. The pollution level of the heavy metals is as following: Cd > Pb > Zn > Cu > As > Cr. The evaluation by Potential Ecological Risk Index shows that the potential ecological risk level in the Bohai bay caused by heavy metals is: Cd > Pb > As > Cu > Zn > Cr. The potential ecological risk of Cr, Cu, Zn, As, Pb is at low level, while Cd is mostly at medium risk level but at serious level in some areas.