Distribution Feature And Assessment Of Petroleum Hydrocarbon And Organochlorine Pesticides In Shellfish From The East China Sea Coastal Areas

In this study, we sampled Crassostrea plicatula , Mytilus edulis , Mactra veneriformis , Meretrix meretrix and Ruditapes philippinarum from 22 sites along the East China Sea coastal areas in May of 2006 and 2007, and detected the concentration of petroleum hydrocarbons, HCHs and DDTs in shellfish by fluorescence spectrophotometry and GC respectively. On the basis of this, the special and temporal distribution feature, composition characteristic and quality assessment of TPHs, HCHs and DDTs as well as ecological risk assessment of HCHs and DDTs were studied. The main conclusions were as follows:(1) Concentrations range of TPHs, HCHs and DDTs in shellfish were 0.40～37.57 mg kg-1, ND～5.42×10-3mg kg-1 and 2.09×10-3～197.66×10-3mg kg-1 with an average of 9.42 mg kg-1 , 1.47×10-3 mg kg-1 and 38.05×10-3 mg kg-1 respectively. The level of TPHs was higher in Changjiang estuary and adjacent waters while levels of HCHs and DDTs were higher in rudong and haimen sites of Jiangsu province as well as in the sites of Zhejiang province. In 2007, concentration of TPHs was almost as much as in 2006, concentration of HCHs was lower while concentration of DDTs was higher than 2006.(2) The composition analysis of HCHs and DDTs showed very high proportion ofα-HCH andβ-HCH but very low ratios ofγ-HCH andδ-HCH , and in most areas the ratios ofα-HCH/γ-HCH was in the range of 4-7 which showed the recent usage of technical HCHs mixture in these areas; Among the isomers of DDTs in survey areas, the ratio of O,P'-DDT/P,P'-DDT was much higher than the O,P'-DDT/P,P'-DDT in technical DDTs which revealed that the usage of Dicofol was the main reason of DDTs pollution in survey areas.(3) The concentrations of TPHs, HCHs and DDTs in shellfish were related to ones in water and sediment clearly. Compared with TPHs and HCHs, DDTs cumulated in shellfish easily; The bioconcentration capacity of oyster was obviously higher than Mactra veneriformis and Mytilus edulis.(4) The quality assessment result indicated that TPHs in some sites were beyond the first grade of Marine Biological of China, and HCHs accorded with the first grade while DDTs were beyond first grade of this standard in most areas. Risk assessment result indicated that both of the cancer risk index and the exposure risk index were acceptable in the studied areas which suggested that HCHs and DDTs posed little or no threat to the health of people in these areas.(5) Compared with other coastal areas, level of TPHs and HCHs in shellfish were in the middle of world level while level of DDTs was higher in the world level.