Center for Environmental Microplastics Studies, Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 511443, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519000, China.
Center for Environmental Microplastics Studies, Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 511443, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519000, China.
Environ Pollut. 2023 Apr 1;322:121227. doi: 10.1016/j.envpol.2023.121227. Epub 2023 Feb 7.
Rivers are recognized as an important pathway for transport of microplastics (MPs) from land to sea, but limited information is available on the spatial distribution and seasonal variation of riverine MPs from upper reaches to estuaries. Such information is critical for source apportionment and development of effective management measures for riverine MPs. To fill the knowledge gap, we investigated the occurrence of MPs in surface water along an urban river in Guangzhou, southern China in wet and dry seasons. The abundances of MPs from 16 sampling sites in the wet and dry seasons varied from 0.123 to 1.84 particles m and from 0.046 to 4.21 particles m, respectively. The spatial distribution of MP abundances showed an increasing trend from upstream to midstream and a decreasing trend from midstream to downstream and estuaries. The abundances of MPs peaked at the midstream, which is surrounded by a highly urbanized region with high population density (∼2530 persons per km). The large surface water runoff during the wet season elevated the MP abundance in riverine water, except for that flowing through the central urban area where the abundance of MPs collected in the dry season was higher than that in the wet season. This was mainly ascribed to the large input from extensive anthropogenic activities and slow water flow rate in urban areas. The estimated monthly riverine MP fluxes from Humen, Hongqili, and Jiaomen were 7.42, 2.38, and 2.3 billion particles, respectively, in the wet season, and 0.86, 0.71, and 0.19 billion particles, respectively, in the dry season. An increase of riverine MP fluxes from Humen, Hongqili, and Jiaomen in the past three years was evident. The results from the present study provide valuable information for source apportionment of riverine MPs and support the initialization of possible MPs controlling measures.
河流被认为是将微塑料（MPs）从陆地输送到海洋的重要途径，但有关上游到河口的河流 MPs 的空间分布和季节性变化的信息有限。此类信息对于源分配和开发有效的河流 MPs 管理措施至关重要。为了填补知识空白，我们调查了中国南方广州市一条城市河流在雨季和旱季地表水的 MPs 发生情况。雨季和旱季 16 个采样点的 MPs 丰度分别在 0.123 到 1.84 个颗粒/米和 0.046 到 4.21 个颗粒/米之间变化。MPs 丰度的空间分布显示出从上游到中游逐渐增加，从中游到下游和河口逐渐减少的趋势。MPs 的丰度在中游达到峰值，中游周围是人口密度高（约 2530 人/平方公里）的高度城市化地区。雨季时大量地表径流增加了河流水体中的 MPs 丰度，除了流经市中心的区域，那里在旱季收集的 MPs 丰度高于雨季。这主要是由于广泛的人为活动和城市地区缓慢的水流速度导致大量输入。虎门、洪奇沥和蕉门在雨季的 MPs 河流月通量估计分别为 74.2、2.38 和 2.3 亿个颗粒，在旱季分别为 0.86、0.71 和 0.19 亿个颗粒。虎门、洪奇沥和蕉门在过去三年中 MPs 河流通量的增加是明显的。本研究的结果为河流 MPs 的源分配提供了有价值的信息，并支持了可能的 MPs 控制措施的初始实施。
