[Occurrence and Ecological Risk Assessment of Typical Persistent Organic Pollutants in Baiyangdian Lake]

A comprehensive survey of the pollution characteristics of persistent organic pollutants (POPs) in the surface water and surface sediment of Baiyangdian Lake was carried out. The survey showed that:① The concentrations of the polycyclic aromatic hydrocarbons(PAHs), organic chlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs) in the surface water of Baiyangdian Lake were 71.32-228.27 ng·L^-1, 2.62-6.13 ng·L^-1, and 0-6.5 ng·L^-1, respectively, and those in the surface sediment were 163.20-861.43 ng·g^-1, 2.25-6.07 ng·g^-1, and 230.96-1224.13 pg·g^-1, respectively. On comparison with historical data, the concentrations of PAHs and OCPs in both the surface water and surface sediment were found to be decreasing, while compared with the domestic and foreign lakes, the concentration of PBDEs in the surface sediment was at a low level. ② The main source of PAHs, both in the surface water and surface sediment in Baiyangdian Lake, originated from fuel discharge and combustion sources. HCHs compose the main part of OCPs in both the surface water (93.76%) and surface sediment (63.10%). In the surface water body, HCHs mainly originated from the degradation of industrial HCHs; in some sites HCHs originated from atmospheric long-distance transmission and the usage of Lindane, while DDTs originated from historical residues. In surface sediment, HCHs mainly originated from the usage of new Lindane, with little industrial HCHs, and DDTs mainly originated from historical residues, while new DDTs may have been used in some sites. BDE-2 (65.80%) composed the main part of PBEDs in the surface water, and it mainly originated from atmospheric long-distance transmission and degradation of high brominated diphenyl ethers; BDE-209 (63.82%) constituted the main part of PBDEs in the surface sediment, and it mainly originated from the commercial Deca-BDEs.③ Ecological Risk Assessment show that there was no obvious ecological risks in Baiyangdian Lake, but in some sites POPs may cause ecological risks; these sites should be monitored more frequently.