干旱区微塑料污染来源、迁移规律与生态风险 postprint

Abstract: Arid regions function as important global sources and sinks for microplastics (MPs), with their unique climatic conditions and human activity patterns giving rise to specific MP pollution characteristics. This article systematically reviews recent advances in understanding MP sources, pollution patterns, migration, and ecological risks within arid environments. Regarding pollution characteristics, soil MP abundance exhibits significant spatial heterogeneity, with fibrous microplastics accounting for 64%–92% of the total. Polyethylene, polypropylene, and nylon are identified as the main polymer components, primarily originating from agricultural film residues. In terms of migration mechanisms, wind erosion and sandstorm events dominate local-to-regional-scale transport. Due to their high aspect ratio and low density, fibrous microplastics are particularly prone to cross-border atmospheric migration, further prolonged by the coupling effect of electric and wind fields on their atmospheric residence time. Ecologically, MPs exert multi-dimensional impacts on ecosystems by altering soil physicochemical properties (e.g., pore structure and water retention capacity), interfering with microbial metabolism, and inducing oxidative stress in plants. Future research efforts should focus on integrating multiscale models, investigating the combined effects of microplastics and other pollutants, and establishing a standardized monitoring system.