Source apportionment and risk assessment of microplastics in the sediments of the Dan river based on APCS-MLR model

Microplastic pollution is becoming a global concern, and tracing its source is essential for effective prevention and control. Therefore, this study aimed to investigate the microplastics in the sediments of the Dan River in China to assess the pollution sources and ecological risks. The results showed that the microplastic abundance ranged from 20 to 2220 items·kg^-1, with polymer composition primarily composed of polypropylene (PP;49.5 %) and polyethylene (PE;15.5 %) in the sediments. Quantitative source analysis using APCS-MLR (absolute principal component score-multiple linear regression) model revealed that, microplastics pollution from two sources: a mixed input from fishery and agricultural activities (65.17 %) and wastewater discharge from laundry and care products (34.83 %). Although overall pollution levels were low, a subset of microplastics with high hazard scores posed potential threats to ecological and environmental security at specific local sites. This study validates the applicability of the APCS-MLR model for microplastics source apportionment and provides a novel methodology for tracing pollution sources.