Environmental fate of microplastics in an urban river: Spatial distribution and seasonal variation

Ting Li; Kai Liu; Rui Tang; Jun-Rong Liang; Lei Mai; Eddy Y Zeng

doi:10.1016/j.envpol.2023.121227

Environmental fate of microplastics in an urban river: Spatial distribution and seasonal variation

Environ Pollut. 2023 Apr 1:322:121227. doi: 10.1016/j.envpol.2023.121227. Epub 2023 Feb 7.

Authors

Ting Li¹, Kai Liu¹, Rui Tang¹, Jun-Rong Liang¹, Lei Mai², Eddy Y Zeng³

Affiliations

¹ 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.
² 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. Electronic address: lei_mai@jnu.edu.cn.
³ 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; Research Center of Low Carbon Economy for Guangzhou Region, Key Laboratory of Philosophy and Social Science in Guangdong Province of Community of Life for Man and Nature, Jinan University, Guangzhou, 510632, China.

PMID: 36758926
DOI: 10.1016/j.envpol.2023.121227

Abstract

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^-3 and from 0.046 to 4.21 particles m^-3, 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 km²). 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.

Keywords: Distribution; Flux; Microplastics; Seasonal variation; Surface water.

MeSH terms

China
Environmental Monitoring / methods
Microplastics*
Plastics
Seasons
Water
Water Pollutants, Chemical* / analysis

Substances

Microplastics
Plastics
Water Pollutants, Chemical
Water