农田土壤微塑料分布、来源和行为特征

微塑料(MPs)作为一种新型污染物广泛存在于农田土壤中.针对农田土壤中微塑料可能发生的污染问题，对全球农田土壤中微塑料的分布、丰度、来源、形状、聚合物组成、尺寸和迁移等方面特征的研究进展进行了综述，提出了研究展望.全球各地所调查农田土壤均有微塑料检出，其来源主要包括农用塑料薄膜、有机肥、污泥、地表径流与农业灌溉、大气沉降和轮胎磨损颗粒.土壤中微塑料形状以碎片、纤维和薄膜为主，微塑料聚合物组成以聚乙烯(PE)、聚丙烯(PP)和聚苯乙烯(PS)为主.农田土地利用方式显著影响土壤中微塑料的丰度，农田土壤中微塑料丰度随颗粒变小而增加.土壤中微塑料可在耕作、淋溶、生物扰动和重力作用下发生迁移.今后应加强土壤微塑料检测方法、数据库建立、安全阈值、迁移转化规律、潜在生态健康风险评价和防控技术体系构建等方面的研究，为农田土壤微塑料污染的风险管控与治理提供参考.

Distribution, Sources, and Behavioral Characteristics of Microplastics in Farmland Soil

Microplastics (MPs) are widely present in farmland soil as an emerging contaminant. This paper serves as a comprehensive and systematic review of research progress on the characteristics of distribution, abundance, sources, shape, polymer composition, size, and migration of MPs in farmland soils around the world. Moreover, research prospects were also proposed. MPs have been detected in farmland soils around the world, mainly coming from agricultural plastic films, organic fertilizers, sludge, surface runoff, agricultural irrigation, atmospheric deposition, and tire wear particles. The morphology of MPs in soil mainly includes debris, fibers, and films. MPs polymer forms mainly include polyethylene, polypropylene, and polystyrene. Farmland land use significantly affects soil MPs abundance. Additionally, the abundance of MPs increase with the reduction in size. MPs in soil can migrate to deep soil through tillage, leaching, bioturbation, and gravity. Research on soil MPs detection methods, database establishment, safety thresholds, migration and transformation laws, potential ecological health risk assessment, and the construction of prevention and control technology systems should be strengthened in the future. The paper can provide a reference for the risk control and governance of farmland soil MPs pollution.