Preliminary Study Of Biological Concentration Polycyclic Aromatic Hydrocarbons And Organochlorine Pesticides In Chaohu Lake

With rapid socioeconomic development and urban intensification, the environmental quality of aquatic ecosystem is gradually deteriorated, thus the survival environment of aquatic organisms is seriously affected. Furthermore, the contaminants accumulated in the aquatic biota can enter human body and threaten human health by comsumption of fishery products, Because of their persistence, bioaccumulation, toxicity and long-range transport potential, polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) are identified and classified as typical persistent organic pollutants (POPs). Most POPs with high hydrophobicity tend to accumulate in the aquatic biota through bioaccumulation and biomagnifications. At high trophic level in various aquatic food webs, as a result, fish is often investigated with high concentrations of POPs. Therefore, investigation into the occurrence of PAHs and OCPs in aquatic food webs and related human exposue by fish consumption has been paid to great attention.Chaohu Lake is one of the five biggest freshwater lakes in China, and is also a fishery base in Eastern China. However, the studies on fish associated bioaccumulation of PAHs and OCPs in Chaohu Lake is still scarce. In the present study,8 species of common fishes (total 64 samples) in Chaohu Lake were collected from both eastern and western areas to determine 16 PAHs identified as prority pollutants by USEPA and 13 OCPs using solid phase extraction and gas chromatography coupled with mass spectrometry. The occurrence and compositional distribution of PAHs and OCPs in fishes were discussed and potential heatlhrisk associated with fishes consumption was evaluated.The results show that all PAHs and OCPs were detectable in all fish samples, with the concentrations varying between 339.4-7084.7 ng/g dry weight and 32.3-290.9 ng/g dry weight, respectively. Coilia ectenes taihuensis and hypophthalmichthys molitrix contained the highest concentration lowest concentration of PAHs, respectively. While Anabarilius and hypophthalmichthys molitrix were determined with the highest and lowest concentration of OCPs. There was no significant variation on residual PAHs in fishes between western and eastern lakes. Higher concentrations of OCPs were observed in the fished from western lake comparing with those from eastern lake In the compositional patterns, indeno[1,2,3-cd]pyrene was the dominant PAHs, accounting for 53.7% of the total PAHs. HCHs and DDTs contributed approximately 40.3% and 13.1% of OCPs, respectively. DDTs was mostly dominated by p, p-DDE, accounting for 80.7% of the total DDTs, and α-HCH was the major HCHs congener with a contribution of 68.8% to the total HCHs.The daily intake of PAHs, HCHs and DDTs were estimiated 13.5～749.3,1.28～ 5.99 and 0.31～3.67 ng/Kg body weight via consumption of fishes from Chaohu Lake. As a result, the potential carcinogenic risk caused by exposure to fish-associated PAHs, DDTs and HCHs were 4.4×10-7-2.0×10-6 and 4.0×10-7～4.8×10-6, indicating high risk to PAHs, but low risk to OCPs for consumers who intake fishes from Chaohu Lake.