[Advances in Microplastics Source Tracing Methodology in Different Environmental Media]

Microplastic pollution has emerged as a critical global environmental issue, affecting diverse environmental media, including water, soil, and the atmosphere. To mitigate microplastic pollution, source identification and control are crucial. However, existing traceability techniques lack comprehensive applicability analyses across different environmental media, and studies focusing on single-medium traceability remain insufficient. Therefore, this study reviews and evaluates seven existing microplastic traceability methods and analyzes their applicability in water, soil, and atmospheric environments. Among these, the source sampling method (SSM) is suitable for water and atmospheric studies, the hybrid single-particle Lagrangian integrated trajectory model (HYSPLIT) is specifically designed for atmospheric research, and the semi-implicit cross-scale hydroscience integrated system model (SCHISM) is primarily applied to microplastic source tracing in aquatic environments. The microplastic occurrence characteristics tracing method (MOC), positive matrix factorization model (PMF), conditional fragmentation model (CFM), and surface contaminants method (SCM) demonstrate applicability across water, soil, and atmospheric media. Although soil microplastics originate from diverse sources, organic fertilizers have been identified as a major contributor. However, the origin of microplastics in organic fertilizers remains unclear, hindering accurate soil microplastic traceability. By synthesizing these methods, it is found that MOC and PMF can be used for the traceability of microplastics in organic fertilizers, providing crucial insights for source control of soil microplastic pollution. This study provides a methodological framework for microplastic traceability across different media and supports comprehensive microplastic pollution prevention strategies.