Microplastic characteristics and microplastic-heavy metal synergistic contamination in agricultural soil under different cultivation modes in Chengdu, China

Yu-Liang Liao; Qi-Xuan Tang; Jin-Yan Yang

doi:10.1016/j.jhazmat.2023.132270

Microplastic characteristics and microplastic-heavy metal synergistic contamination in agricultural soil under different cultivation modes in Chengdu, China

J Hazard Mater. 2023 Oct 5:459:132270. doi: 10.1016/j.jhazmat.2023.132270. Epub 2023 Aug 11.

Authors

Yu-Liang Liao¹, Qi-Xuan Tang¹, Jin-Yan Yang²

Affiliations

¹ College of Architecture and Environment, Sichuan University, Chengdu 610065, China; Yibin Institute of Industrial Technology, Sichuan University Yibin Park, Yibin 644000, China.
² College of Architecture and Environment, Sichuan University, Chengdu 610065, China; Yibin Institute of Industrial Technology, Sichuan University Yibin Park, Yibin 644000, China. Electronic address: yanyang@scu.edu.cn.

PMID: 37573825
DOI: 10.1016/j.jhazmat.2023.132270

Abstract

Microplastics have significant implications for global ecosystems. The microplastic distribution, types, sources, and quantified microplastic-heavy metal synergistic pollution in agricultural soil in Chengdu, China were analyzed. The microplastics were detected in all soil samples collected from 103 sites, with concentrations ranging from 1333 to 15067 particle kg^-1. The abundance of microplastics in grassland (12,667 ± 3394 particle kg^-1) was more than twice higher than that in open field, vegetable field, orchard, and woodland. The main morphological types of microplastics included fibers, films, and granules (all "3-Dimensional" microplastics), with the colors red, blue, and transparent. Granular and fiber microplastics were predominantly in particles < 500 mm, while film microplastics were uniformly distributed at all sizes. The plastic compositions were mainly polypropylene and polyethylene plastics, accounting for 20.73% and 27.90% of the soil microplastic, respectively. Agricultural plastic applications and irrigation water were the sources of soil microplastics. The concentration of Cd, Cr, and Cu in the microplastics was strongly correlated with the corresponding concentration in the soils (p < 0.01), and the microplastic-heavy metal synergistic pollution might deteriorate the soil environment. The results of soil TOC measurements were influenced by microplastics in the soil. The results provide important data for the characteristics of microplastics in the agroecosystem.

Keywords: Agricultural soil; Distribution; Heavy metal contamination; Microplastics; Soil TOC.