Distribution Characteristics and Ecological Risk Assessment of Microplastic Pollution in the Water Body of Dasha River in Jiaozuo City

Microplastic is one of the new pollutants, with a wide range of sources and distributions, and it can also be used as a carrier to adsorb heavy metals, persistent organic pollutants, and other hazardous substances in the environment, which constitutes a potential threat to the health of biological human beings. However, there is only one study on microplastic water pollution in Jiaozuo City, Qin River. In this study, 19 sampling stations in Dasha River in Jiaozuo City were sampled in March 2025, and microplastic abundance, shape, color, and particle size were analyzed by body-view microscopy, and the results showed that microplastics were detected at 100% in all sampling stations, with an abundance range of 0.9-10.6 n-L-1 and an average abundance of 3.90 ± 2.83 n-L The average abundance was 3.90 ± 2.83 n-L-1. Fibers were the main form of microplastics in the Dasha River, with black and transparent colors and particle sizes ranging from 0.3 to 1.0 mm. The polymer types were further identified with the help of micro Fourier transform infrared (FTIR) instrument, and it was found that polyethylene terephthalate (PEGT), polyamide, and polypropylene were the main microplastic species in the study area. The results of the ecological risk assessment showed that the microplastic pollution load of the Dasha River in Jiaozuo City was at low risk (level I), while the polymer risk index of the sampling stations with high hazard scores of PVC and PAN was high, and even reached very high risk in the S19 sampling station. The results of this study can provide a reference for Jiaozuo City to recognize the microplastic pollution situation in rivers and to prevent and control the risk.