Heavy Metals in the Surface Sediments of the North Yellow Sea and Its Ecological Risk

During the investigation in China's North Yellow Sea Area in the autumn of 2007,the concentrations of six heavy metals in the surface sediments were determined by AAS and AFS,and single factor method and the potential ecological risk index method were used to assess their ecological risk.The results showed that the average contents of Cu,Zn,Pb,Cd,Hg and As were(11.6±1.9),(25.2±2.4),(52.7±5.4),(0.22±0.02),(0.07±0.01),(13.3±1.3)μg/g in the North Yellow Sea.Environmental assessment with single factor method suggested that the sediments were not polluted by Cu,Zn,Pb,Cd ang Hg,while moderately contaminated with As.Ecological risk index suggested that the pollution degree of these heavy metals in the surface sediments followed the order: HgCdAsPbCuZn,and its mild ecological risk area.