Institute of Lake Environment, National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, State Environmental Protection Scientific Observation and Research Station for Lake Dongtinghu (SEPSORSLD), Research Centre of Lake Environment, State Environmental Protection Key Laboratory for Lake Pollution Control, State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
Institute of environment, Tsinghua University, Beijing, 100084, China.
Environ Sci Pollut Res Int. 2018 Dec;25(34):34076-34090. doi: 10.1007/s11356-018-3329-8. Epub 2018 Oct 3.
In this study, 15 representative surface waters and sediments and seven typical fish were collected during the wet season in 2016 to explore the occurrence, chemical fractionation, and ecological risk of heavy metals (Cu, Zn, Pb, Cd, Cr, Hg, As, and Ni) in aquatic ecosystems of Dongting Lake in China. In surface water, the concentrations of all elements were lower than the third grade of the surface water quality standards (GB3838-2002). The highest concentrations of Zn, Pb, Cd, Ni, and Cu were found in the outlet of Dongting Lake, whereas As and Cr were highest in the Xiangjiang River Delta area. In surface sediments, the concentration decreased in the order of Zn > Cr > Pb > Cu > Ni > As>Cd > Hg; the highest concentration of all elements, except for Hg, was located in the Xiangjiang River Delta area; for chemical fractionation, Cr, Hg, Zn, As, Ni, and Cu were mainly residual fractionation; and Pb and Cd were mainly in a reducible state and fraction soluble in acid, respectively. In fish muscle, the concentrations of all elements were lower than relevant standards; the highest concentration appeared in fish living in the middle-lower and demersal layers. As for the feeding habits of fish, the average concentration decreased in the order of carnivorous > omnivorous > herbivorous fish. The potential ecological risk and the ratio of secondary phase to primary phase assessment showed that Cd and Hg had the highest ecological risk and that Cd and Pb had a high risk of secondary release. A health risk assessment showed that drinking water and fish for consumption in urban and rural areas around Dongting Lake were in the acceptable level.
本研究于 2016 年丰水期采集了洞庭湖 15 个典型地表水和底泥以及 7 种代表性鱼类样品，以探讨中国洞庭湖水生态系统中重金属（Cu、Zn、Pb、Cd、Cr、Hg、As 和 Ni）的赋存、化学形态和生态风险。在地表水中，所有元素的浓度均低于《地表水环境质量标准》（GB3838-2002）中的三级标准。Zn、Pb、Cd、Ni 和 Cu 的浓度在洞庭湖出口处最高，而 As 和 Cr 则在湘江三角洲地区最高。在底泥中，浓度顺序为 Zn>Cr>Pb>Cu>Ni>As>Cd>Hg；除 Hg 外，所有元素的最高浓度均位于湘江三角洲地区；对于化学形态，Cr、Hg、Zn、As、Ni 和 Cu 主要为残渣态；而 Pb 和 Cd 则主要为可还原态和酸溶态。在鱼类肌肉中，所有元素的浓度均低于相关标准；最高浓度出现在中下层和底层鱼类中。就鱼类的摄食习性而言，平均浓度顺序为肉食性>杂食性>草食性。潜在生态风险和次生相与原生相比值评估表明，Cd 和 Hg 的生态风险最高，Cd 和 Pb 的次生释放风险较高。健康风险评估表明，洞庭湖周边城乡地区的饮用水和食用鱼类处于可接受水平。
