Risk assessment and zoning of soil microplastics in a typical megacity, China

Yanqing Wang; Sophia Shuang Chen; Guanghui Zheng; Shenglu Zhou; Yujie Zhou

doi:10.1016/j.jhazmat.2025.138870

Risk assessment and zoning of soil microplastics in a typical megacity, China

J Hazard Mater. 2025 Jun 7:495:138870. doi: 10.1016/j.jhazmat.2025.138870. Online ahead of print.

Authors

Yanqing Wang¹, Sophia Shuang Chen², Guanghui Zheng², Shenglu Zhou³, Yujie Zhou⁴

Affiliations

¹ College of Geographical Sciences, Nanjing University of Information Science & Technology, Nanjing 210044, China; Changwang School of Honors, Nanjing University of Information Science & Technology, Nanjing 210044, China.
² College of Geographical Sciences, Nanjing University of Information Science & Technology, Nanjing 210044, China.
³ School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210046, China.
⁴ College of Geographical Sciences, Nanjing University of Information Science & Technology, Nanjing 210044, China; Changwang School of Honors, Nanjing University of Information Science & Technology, Nanjing 210044, China. Electronic address: gerryzhou@nuist.edu.cn.

PMID: 40505405
DOI: 10.1016/j.jhazmat.2025.138870

Abstract

As emerging pollutants, microplastics (MPs) may threaten urban soil and human health. Here, we used quantitative models and geostatistical analysis to evaluate MP risks and influencing factors in Nanjing, a typical megacity in China. We also identified areas with different risk control needs. Results showed spatial variability in MP risks, with higher risks in the western region compared to the eastern region. Residential, government, and industrial areas were pollution hotspots. Factors like washing-related points of interest (POIs) and soil properties significantly influenced MP risks. Risk areas were categorized based on MP concentration and polymer risks. HRCZ-CP, the highest-risk area, distributed primarily in commercial zones and other human-dense areas heavily influenced by traffic and packaging-related POIs, requires close monitoring of anthropogenic emissions. Two secondary risk categories were identified: HRCZ-NH (high concentration risk near water) and HRCZ-H (high polymer risk in public green spaces). Future efforts should focus on controlling MP runoff in HRCZ-NH and managing soil MP retention and degradation in HRCZ-H. The clean zone (CZ), with the lowest risk, should maintain environmental standards. This study provides a basis for targeted management of urban soil MP risks.

Keywords: Microplastics; Pollution zoning; Risk assessment; Urban soil.