Spatio-temporal variations and ecological risks of organochlorine pesticides in surface waters of a plateau lake in China. (September 2022)

• Record Type: Journal Article
• Authors: Chen, Chong; Luo, Jiahong; Shu, Xingquan; Dai, Wenshao; Guan, Mengsha; Ma, Limin
• Is Part Of: Chemosphere. Volume 303:Part 1(2022)
• Publication Date: 2022-09
• Subjects: Qilu Lake Basin -- Concentration -- Correlation -- Risk quotient; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2022.135029
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Qilu Lake is one of the 9 plateau lakes in Yunnan, China, with a lake surface altitude of 1796.62 m above sea level. In spite of the importance and agriculturally-intensive phenomenon in Qilu Lake Basin, few studies have provided a modern evaluation of pesticide residues and potential effects to local aquatic organisms. The primary goal of this study was to determine the spatio-temporal variations of organochlorine pesticides (OCPs) in this area, and to further assess the related ecological risks. Of the 25 OCPs analyzed, 14 were detected, and the concentrations of ∑25 OCPs were highest in the upstream of rivers, followed by regions close to the lake shore, and the lowest concentrations were found in Qilu Lake in every season except winter. The concentrations of ∑25 OCPs were the highest in summer, and the lowest in winter. OCP concentrations in spring and in autumn were similar. 4, 4′-DDD, γ-HCH, HCB, trans -chlordane, and cis -chlordane were 5 OCPs with relatively high risk in Qilu Lake Basin. Interestingly, higher OCP concentrations do not necessarily correspond to higher ecological risk levels. Low predicted no-effect concentration (PNEC) values and relatively high toxicity of these OCPs led to their high risk quotient (RQ) values. This work further illustrated that although OCPs have been banned for many years, they were still frequently detected in surface waters, and caused risks to aquatic animals. Graphical abstract: Image 1 Highlights: OCPs concentrations were highest in the upstream of rivers and in summer. Intensive precipitation in summer strongly affected pesticide migration. Pesticides with similar properties had similar migration pathways. Sediments could be a major source of OCP residues in waters. γ-HCH presented the highest-risk level in Qilu Lake Basin.