Distribution and Potential Ecological Risk Assessment of Heavy Metals in Surface Sediments from Zhifu Bay,the Yellow Sea

The surface sediment samples from sixteen stations of Zhifu Bay,the Yellow Sea,were collected in July 2009 and the concentrations of eight heavy metals,including Hg,Cu,Pb,Cd,Zn,Ni,Co and Mn were determined.The results showed that the concentrations of heavy metals in Zhifu Bay were generally low,which were less than the national standard levels of grade I sediments.The average concentrations of Hg,Cu,Pb,Cd,Zn,Ni,Co,Mn were 0.02,12.3,8.67,0.13,32.8,11.4,5.00,229 mg·kg-1,respectively.The pollution levels and potential ecological risk levels of heavy metals were evaluated by geoaccumulation index and Hakanson′s method,and the results demonstrated the pollution and potential ecological risks of Hg and Cd were higher than those of the other metals.The levels of heavy metals in this survey were generally lower than that of the previous study,suggesting an improvement of marine environments in recent years.