Diverse and high pollution of microplastics in seasonal snow across Northeastern China

Hanxuan Wen; Han Xu; Yuling Ma; Chunyu Zhang; Daizhou Zhang; Xin Wang

doi:10.1016/j.scitotenv.2023.167923

Diverse and high pollution of microplastics in seasonal snow across Northeastern China

Sci Total Environ. 2024 Jan 10:907:167923. doi: 10.1016/j.scitotenv.2023.167923. Epub 2023 Oct 18.

Authors

Hanxuan Wen¹, Han Xu², Yuling Ma¹, Chunyu Zhang¹, Daizhou Zhang³, Xin Wang⁴

Affiliations

¹ Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China.
² State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, Tianjin Key Laboratory of Urban Transport Emission Research, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
³ Faculty of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto, Kumamoto 862-8502, Japan.
⁴ Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China; Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China. Electronic address: wxin@tju.edu.cn.

PMID: 37858829
DOI: 10.1016/j.scitotenv.2023.167923

Abstract

Snow scavenging is recognized as one of the major sinks for atmospheric microplastics (MPs). However, little is known about the properties of MPs in large-scale surface snow. Using Nile Red staining and micro-Fourier transform infrared spectroscopy, we identified the shapes, sizes, and polymer components of MPs in seasonal snow across northeastern (NE) China, a major industrial area. The average concentration of MPs was (4.52 ± 3.05) × 10⁴ MPs L^-1, and the highest contamination (6.65 ± 3.89) × 10⁴ MPs L^-1 was observed in Changbai Mountains, which was the highest concentration observed in surface snow to the extent of literature. The majority of snow MPs were smaller than 50 μm and composed primarily of fragments. Ethylene vinyl acetate and polyethylene were the dominant contributors to their chemical components. Investigation with positive matrix factorization revealed that the MPs were primarily generated by debris from packaging materials, followed by industrial and construction activities. In addition, the winter atmospheric circulation over the northwestern Siberian and Mongolian plateaus likely dominated the wide-range dispersion and deposition of the MPs across NE China. These results provide a first comprehensive perspective of MPs from sources to removal associated with snow in a large geographic region.

Keywords: Degradation; Emission sources; Microplastics; Nile Red staining; Seasonal snow.