Heavy metal contamination in the marine organisms in Yantai coast, northern Yellow Sea of China.

The port city of Yantai, in Shandong province China is located on Sishili Bay in the northern Yellow Sea. Intense human activity associated with urban sewage discharge, as well as industrial and maritime activities, have stressed the Sishili Bay coastal ecosystem with anthropogenic pollution. The aim of this study was to measure the levels of heavy metal in the sediment and marine organisms of economic value from various sites within Sishili Bay, and to evaluate the data in relation to the potential health risk on human consumers. For this purpose, sediment and wild shrimps and crab were collected from three areas (a total of 13 sampling sites) of the Yantai coast and analyzed for six heavy metals (Cu, Zn, Cr, Ni, Pb, and As). For comparison, the concentrations of the same heavy metals in seven kinds of mollusks obtained from local aquaculture were also determined. The findings showed that the concentrations of heavy metals in the sediment of Yantai coast followed the order Zn > ≈Cr > Cu ≈ Ni ≈ Pb > As, and all were within the safe levels of national standard. However, the concentrations of the heavy metals varied significantly in the organism samples, indicating the different accumulative abilities of the species sampled. For the wild marine organisms, Pb concentrations in some shrimp and crab samples exceeded the standard limit of seafood safety criteria and As concentrations in all samples were over the limit. Moreover, the As levels in mollusks from aquaculture exceeded the limit of seafood standard criteria. These results indicated that the heavy metal levels in the marine organisms in the studied areas were moderate but unacceptable for As from the view of safety of seafood. Furthermore, it is very necessary and important to further study toxicological and ecological effect of As in the coast of northern Yellow sea to understand the potential for risk to human and environmental health.