Characterization and traceability analysis of dry deposition of atmospheric microplastics (MPs) in Wuliangsuhai Lake

Kai Wang; Yu Liu; Xiaohong Shi; Shengnan Zhao; Biao Sun; Junping Lu; Wenbao Li

doi:10.1016/j.scitotenv.2023.168201

Characterization and traceability analysis of dry deposition of atmospheric microplastics (MPs) in Wuliangsuhai Lake

Sci Total Environ. 2024 Jan 1:906:168201. doi: 10.1016/j.scitotenv.2023.168201. Epub 2023 Oct 31.

Authors

Kai Wang¹, Yu Liu², Xiaohong Shi³, Shengnan Zhao³, Biao Sun³, Junping Lu³, Wenbao Li³

Affiliations

¹ Water Conservancy and Civil Engineering, College of Inner Mongolia Agricultural University, Hohhot 010018, China.
² Water Conservancy and Civil Engineering, College of Inner Mongolia Agricultural University, Hohhot 010018, China; Inner Mongolia Water Resource Protection and Utilization Key Laboratory, Hohhot 010018, China; State Gauge and Research Station of Wetland Ecosystem, Wuliangsuhai Lake, Inner Mongolia, Bayan Nur 014404, China; Autonomous Region Collaborative Innovation Center for Integrated Management of Water Resources and Water Environment in the Inner Mongolia Reaches of the Yellow River, Hohhot 010018, China. Electronic address: yuliu@imau.edu.cn.
³ Water Conservancy and Civil Engineering, College of Inner Mongolia Agricultural University, Hohhot 010018, China; Inner Mongolia Water Resource Protection and Utilization Key Laboratory, Hohhot 010018, China; State Gauge and Research Station of Wetland Ecosystem, Wuliangsuhai Lake, Inner Mongolia, Bayan Nur 014404, China.

PMID: 37918738
DOI: 10.1016/j.scitotenv.2023.168201

Abstract

Microplastics (MPs) represent a contaminant of emerging concern that may negatively impact lacustrine ecosystems. It is important, then, to manage and reduce the influx of MPs to lakes, a process that requires the identification of MP sources. In this study, atmospheric MP samples were collected and analyzed from 6 sampling sites in the Wuliangsuhai Lake area from March to June 2021, and used to determine atmospheric depositional fluxes of MPs to the lake surface. The sources of MPs were also explored on the basis of MP characteristics and by determining atmospheric flow patterns to the sampling sites using a backward trajectory model (HYSPLIT). The average atmospheric depositional flux of MPs to the Wuliangsuhai Lake area (3371 ± 1423 n/d·m²) is several times higher than rates measured in other areas. MPs were predominately composed of small (0.05-0.5 mm), transparent fibers; a small percentage of particles consisted of fragments, thin films, or lumpy MPs. Compositionally, most MPs were composed of polyethylene (PE), polyethylene terephthalate (PET), and polystyrene (PS). The former polymer types are indicative of fibers from textiles, including those from textile plants in adjacent cites. The latter (PS) type is presumably derived from degraded food containers and other items associated with tourism. PE was also identified in association with thin films, which were likely derived from bags and/or agricultural plastics. MP characteristics, combined with spatial variations in depositional rates and the results of the backward trajectory model, suggest most atmospherically deposited MPs in the Wuliangsuhai Lake area were transported to the sampling sites from large cities external to the basin, and, to a much lesser degree, areas of tourism within the lake environment. The results of the study provide a theoretical basis for assessing atmospheric MP deposition within inland lake areas as well as for the prevention and control of MP pollution.

Keywords: Atmospheric deposition; Backward trajectory modeling; Microplastics; Source analysis.