Soil erosion is a major drive for nano & micro-plastics to enter riverine systems from cultivated land

Yanting Wang; Siyuan Jing; Peiyu Hou; Rui Ni; Lili Niu; Thomas Cherico Wanger; Weiping Liu; Kai Liu

doi:10.1016/j.watres.2024.121597

Soil erosion is a major drive for nano & micro-plastics to enter riverine systems from cultivated land

Water Res. 2024 Apr 9:256:121597. doi: 10.1016/j.watres.2024.121597. Online ahead of print.

Authors

Yanting Wang¹, Siyuan Jing², Peiyu Hou³, Rui Ni¹, Lili Niu⁴, Thomas Cherico Wanger⁵, Weiping Liu⁶, Kai Liu⁷

Affiliations

¹ MOE Key Laboratory of Environmental Remediation and Ecosystem Health, Institute of Environmental Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
² Sustainable Agricultural Systems & Engineering Laboratory, School of Engineering, Westlake University, 18 Shilongshan Road, Hangzhou, Zhejiang 310024, China.
³ Division of Environment and Resources, College of Engineering, Westlake University, Hangzhou, Zhejiang 310024, China.
⁴ Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy, Zhejiang Shuren University, Hangzhou, Zhejiang 312028, China.
⁵ Sustainable Agricultural Systems & Engineering Laboratory, School of Engineering, Westlake University, 18 Shilongshan Road, Hangzhou, Zhejiang 310024, China; ChinaRiceNetwork.org, Hangzhou 310024, China.
⁶ Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy, Zhejiang Shuren University, Hangzhou, Zhejiang 312028, China. Electronic address: wliu@zju.edu.cn.
⁷ Division of Environment and Resources, College of Engineering, Westlake University, Hangzhou, Zhejiang 310024, China. Electronic address: liukai@westlake.edu.cn.

PMID: 38614030
DOI: 10.1016/j.watres.2024.121597

Abstract

Nano and micro-plastics (NMPs, particles diameter <5 mm), as emerging contaminants, have become a major concern in the aquatic environment because of their adverse consequences to aquatic life and potentially human health. Implementing mitigation strategies requires quantifying NMPs mass emissions and understanding their sources and transport pathways from land to riverine systems. Herein, to access NMPs mass input from agricultural soil to riverine system via water-driven soil erosion, we have collected soil samples from 120 cultivated land in nine drainage basins across China in 2021 and quantified the residues of six common types of plastic, including polyvinyl chloride (PVC), polymethyl methacrylate (PMMA), polypropylene (PP), polyethylene (PE), polycarbonate (PC), and polystyrene (PS). NMPs (Σ₆plastics) were detected in all samples at concentrations between 3.6 and 816.6 μg/g dry weight (median, 63.3 μg/g) by thermal desorption/pyrolysis-gas chromatography-mass spectrometry. Then, based on the Revised Universal Soil Loss Equation model, we estimated that about 22,700 tonnes of NMPs may enter the Chinese riverine system in 2020 due to agricultural water-driven soil erosion, which occurs primarily from May to September. Our result suggested that over 90% of the riverine NMPs related to agricultural soil erosion in China are attributed to 36.5% of the country's total cultivated land, mainly distributed in the Yangtze River Basin, Southwest Basin, and Pearl River Basin. The migration of NMPs due to water-driven soil erosion cannot be ignored, and erosion management strategies may contribute to alleviating plastic pollution issues in aquatic systems.

Keywords: Agriculture soil; Microplastics; Nanoplastic; Revised Universal Soil Loss Equation Model; TD/Py-GC–MS.