Distribution, Sources and Ecological Risk Assessment of Organochlorine Pesticides and Polychlorinated Biphenyl Residues in Surface Sediment from Dahuofang Reservoir, Liaoning
辽宁大伙房水库沉积物中有机氯农药和多氯联苯的分布、来源及风险评价

Twenty-four surface sediment samples collected in Dahuofang Reservoir were analyzed for organochlorine pesticides(OCPs) and polychlorinated biphenyl(PCBs) residues. The results showed that the recent occurrence levels in sediments were 0.70-3.48 ng·g-1(with a mean of 1.58 ng·g-1±0.71 ng·g-1) for HCHs, 0.85-4.94 ng·g-1(1.94 ng·g-1±0.82 ng·g-1) for DDTs, 1.46-3.52 ng·g-1(2.42 ng·g-1±0.64 ng·g-1) for PCBs. The inputs of OCPs and PCBs could be attributed to the recent use of relevant products and the heavy historical application which preserved in agricultural soil in adjacent area. Contamination level of OCPs and PCBs in surface sediments decreased from upstream to downstream, and samples of higher contamination level were located in Hunhe river mouth, both of which indicated distribution of OCPs and PCBs in reservoir was influenced by riverine discharge. The ecological risk assessment suggested that the OCPs in the sediments of the study area might pose a bit high harm to the environment, while PCBs might pose little harm to the environment.