LIN Tian 1，MA Chuan-liang 2，WANG Li-fang 1,*，GUO Jian-yang 1
(1.The State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China;
2. Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China)
Abstract: The Dianchi Lake is the largest lake in Yunnan Province and the sixth largest freshwater lake in China, with a reputation of a Pearl Imbedded on the Plateau. It plays a very important role in agriculture and the water supply of Kunming City. However, comprehensive studies on the environmental pollution of persistent organic pollutants in the Dianchi Lake have not been carried out in recent years. In this study, we collected eleven sediment samples from the Dianchi Lake to evaluate the contamination and ecological risks caused by OCPs and PCBs. The contamination pattern was DDTs > HCHs > PCBs. DDTs were the most abundant pollutants, their concentrations ranging from 0.26 to 75.20 ng/g dry weight, followed by HCHs from 0.63 to 26.0 ng/g and PCBs from 0.64 to 17.07 ng/g. The concentrations of DDTs, HCHs and PCBs decreased sharply, by 1 or 2 orders of magnitude, from the upper section to the lower section because of being obstructed by the dam. The PCB homologue profiles were dominated by less chlorinated compounds with tri-PCBs and penta-PCBs, which are related to the historical production and use of PCBs in China. The isomer ratios of (p,p'-DDE + p,p'-DDD)/DDTs (>0.84) and β-HCH/HCHs (>0.45) suggested that the input of OCPs could be attributed to the heavy historical application which was preserved in agricultural soil in adjacent areas. Some sediment samples had higher concentrations of DDT compounds and γ-HCH than the standards from the Canadian Environmental Quality Guideline, suggesting the OCPs in the sediments of the upper Dianchi Lake might have posed a bit high harm to the aquatic environment.
Key words: PCBs; OCPs; distribution; risk assessment; sediment; Dianchi Lake
EARTH AND ENVIRONMENT Vol. 42, No.5, Tot No.301, 2014, Page 625-630
