Study of soil microplastic pollution and influencing factors based on environmental fragility theory

Xiuyuan Yang; Zhenming Zhang; Jiachun Zhang

doi:10.1016/j.scitotenv.2023.165435

Study of soil microplastic pollution and influencing factors based on environmental fragility theory

Sci Total Environ. 2023 Nov 15:899:165435. doi: 10.1016/j.scitotenv.2023.165435. Epub 2023 Jul 11.

Authors

Xiuyuan Yang¹, Zhenming Zhang², Jiachun Zhang³

Affiliations

¹ College of Resources and Environmental Engineering, Guizhou University, Guiyang 550025, Guizhou, China.
² College of Resources and Environmental Engineering, Guizhou University, Guiyang 550025, Guizhou, China; Key Laboratory of Kast Georesources and Environment, Ministry of Education, Guizhou University, Guiyang 550025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guiyang 550025, China. Electronic address: zhangzm@gzu.edu.cn.
³ Guizhou Botanical Garden, Guizhou Academy of Sciences, Guiyang 550004, Guizhou, China. Electronic address: gs.jczhang20@gzu.edu.cn.

PMID: 37442481
DOI: 10.1016/j.scitotenv.2023.165435

Abstract

Soil microplastics (MPs) pollution is a global concern, but the distribution of MPs and the factors affecting the distribution of MPs in different ecologically fragile karst areas remain poorly understood. Here, we investigated the spatial distribution, characteristics, and composition of MPs in different ecologically fragile karst areas of Guizhou Province and explored the relationship between ecosystem fragility and MPs. Structural equation models combined with robust random forest (RF) models were used to clarify the effects of karst soil properties on MPs and quantify their relative contributions. The abundance of soil MPs in ecologically fragile karst areas was 2949 item kg^-1, and the risk of MPs contamination was highest in medium-fragile areas. The robust RF models precisely predicted the abundance of soil MPs in different fragile areas, and the mean root mean square error and R² were 0.21 and 0.93, respectively. The contribution of karst soil properties to the abundance of MPs was estimated. Some soil chemical properties had a significant effect (p < 0.05) on MPs pollution in ecologically fragile karst areas. The results of our study suggest that the fragile ecological environment may exacerbate MPs pollution. Our study also contributes to establish a scientific theoretical foundation for the utilization of plastics and the prevention and control of microplastics pollution in karst ecosystems.

Keywords: Fragile ecology; Karst; Microplastics; Robust random forest; Soil.