Occurrence and distribution of persistent organic pollutants in water of Chinese lakes and reservoirs

Abstract

Persistent organic pollutants (POPs) are widespread and persistent in the environment, and most of them are teratogenic, carcinogenic, and mutagenic. China is one of the countries with a high density of lakes in the world. Lakes play an important role in many aspects such as water supply, fisheries, and maintenance of ecosystem diversity. In addition, lakes are important sinks of POPs. The POPs in lake water can absorb and be utilized by aquatic organisms, which poses great risk to ecosystems and human health. Therefore, the distribution of POPs in lake water has an important impact on the surrounding ecosystem and human health. We collected 80 articles on the topic of POPs in Chinese lake water published from 2003 to February 2019. We collected and analyzed the published data of polycyclic aromatic hydrocarbons (PAHs), hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethane (DDX), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), polychlorinated diphenyl ethers (PCDEs), perfluorinated compounds (PFCs), and phthalate esters (PAEs). The POPs in Chinese lake water have been investigated in 49 lakes, involving 19 provinces, municipalities and autonomous regions in China, mainly located in the eastern region (n=32), and Yunnan-Guizhou Plateau (n=14). There were fewer studies in the Qinghai-Xinjiang Lake District (n=3), and other areas. Among them, PAHs, HCHs and DDX were the most studied POPs. Their average concentrations of ΣPAHs, ΣHCHs, and ΣDDX in Chinese lake water were 360.0±433.8 ng/L (n=26), 12.8±23.5 ng/L (n=30), and 12.8±24.6 ng/L (n=24). The concentrations of POPs in water of eastern lakes were higher than those in lakes in other areas. Although the relative proportions of ΣPAHs, ΣHCHs and ΣDDX to the concentration of total pollutants did not change significantly before and after the year of 2010, their concentrations decreased, suggesting that the compliance with the Stockholm Convention on persistent organic pollutants (POPs) and the mitigation of PAHs were effective in China. The depth of water (overlying water and interstitial water), sampling location (the inlet and outlet of lakes and within the lakes) were important factors for concentrations of POPs in Chinese lake water. The concentrations of POPs in Chinese lake water were correlated with human activities such as agricultural farming, domestic sewage, industrial sewage, and docks, and the type of POPs and geographical location of the studied area. Based on the research data collected from a large number of published literatures, this review revealed the distribution characteristics of POPs in Chinese lake water, and provided a scientific basis for the control and mitigation of POPs in Chinese lakes.