Yang Runlan, Han Xu, Wang Yutao, Liu Yanxin, Sun Qingqing, Su Haijie, Peng Shuchan, Lu Peili, Zhang Daijun, Zhou Shangbo
Department of Environmental Science, School of Environment and Ecology, Chongqing University, Chongqing, 400045, China.
Department of Civil and Environmental Engineering, University of Missouri, Columbia, MO, 65211, United States.
Environ Res. 2025 Jun 15;275:121440. doi: 10.1016/j.envres.2025.121440. Epub 2025 Mar 19.
The construction of dams disrupts the natural connectivity of rivers, potentially altering the distribution and movement of pollutants. However, the impacts of dams on microplastic (MP) flux are scarcely considered. By integrating previous findings and conducting supplementary sampling, we mapped the distribution of MPs in the Three Gorges Reservoir (TGR), covering surface water, sediment, the hydro-fluctuation belt, and the riparian zone. The TGR serves as a significant accumulation zone for MPs, with a notably higher concentration of MPs in its water compared to the upstream river water. In the reservoir, MPs are concentrated in the upstream and downstream sections of the water column, the hydro-fluctuation belt and sediment, whereas in the riparian zone, concentrations are higher in the downstream section. The distribution of MPs in reservoir water is strongly correlated (R > 0.9) with regional gross domestic product (GDP) and sewage discharge, whereas the factors influencing MPs in sediment, the hydro-fluctuation belt, and the riparian zone are more complex. Human activities, particularly wastewater discharge in populated areas, predominantly contributed 49.89 % to the MPs load in the reservoir. The TGR captures approximately 11,091 ± 6,998 tons of MPs annually, constituting 28.18 % of the MPs flux from the upper Yangtze River.
水坝的建设破坏了河流的自然连通性，可能改变污染物的分布和移动。然而，水坝对微塑料（MP）通量的影响却很少被考虑。通过整合先前的研究结果并进行补充采样，我们绘制了三峡水库（TGR）中微塑料的分布图，涵盖了地表水、沉积物、消落带和河岸带。三峡水库是微塑料的一个重要聚集区，其水体中微塑料的浓度明显高于上游河水。在水库中，微塑料集中在水柱的上游和下游部分、消落带和沉积物中，而在河岸带，下游部分的浓度较高。水库水体中微塑料的分布与区域国内生产总值（GDP）和污水排放密切相关（R>0.9），而影响沉积物、消落带和河岸带中微塑料的因素则更为复杂。人类活动，特别是人口密集地区的废水排放，对水库中微塑料负荷的贡献率主要为49.89%。三峡水库每年捕获约11,091±6,998吨微塑料，占长江上游微塑料通量的28.18%。
