Microplastics (MPs) are a growing environmental concern, with expanding areas of harm. The soil environment is the main site for the production, consumption and even disposal of plastics and plastic products, and thus faces the serious issue of microplastic contamination. This article reviews the migration, biodegradation, toxicity and risk assessment of MPs in soil environment. Biological action and abiotic action jointly cause the migration of MPs in the soil, and their migration path is also influenced by the soil properties, microplastic self-structure, and natural factors. The diversity of microplastic migration may pose a challenge in detecting MPs. Biodegradation of MPs in soil includes microbial degradation and soil microfauna degradation. The mechanism of biodegradation relies on enzymes that break down MPs within the organism. It has been demonstrated that MPs can exert toxic effects on plants, which include the alteration of external soil conditions or the hazard on the plant itself, occurring at various stages of plant growth and development. The Pollution Load Index (PLI) and the Polymer Hazard Index (PHI) are the most commonly used methods for assessing the environmental risk of MPs.

中文翻译：

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深入了解土壤环境中的微塑料：迁移、生物降解、毒性和风险评估


微塑料 (MP) 是一个日益严重的环境问题，其危害范围不断扩大。土壤环境是塑料及塑料制品生产、消费乃至处置的主要场所，面临着严重的微塑料污染问题。本文综述了MPs在土壤环境中的迁移、生物降解、毒性和风险评估。生物作用和非生物作用共同引起MPs在土壤中的迁移，其迁移路径还受到土壤性质、微塑性自结构和自然因素的影响。微塑料迁移的多样性可能对检测 MP 提出挑战。土壤中MPs的生物降解包括微生物降解和土壤微型动物降解。生物降解机制依赖于生物体内分解 MP 的酶。已证明 MP 可以对植物产生毒性作用，包括改变外部土壤条件或对植物本身造成危害，发生在植物生长和发育的各个阶段。污染负荷指数（PLI）和聚合物危害指数（PHI）是评估MP环境风险最常用的方法。