Microplastic Pollution in Typical Subtropical Rivers in Eastern China: A Case Study of the Feiyun River Basin

The widespread and excessive use of plastic in our daily life has led to serious microplastic pollution in the atmosphere, water, and soil. These microplastics can enter freshwater systems and pose significant risks to the ecosystem and human health via the food chain. This environmental problem deserves proper investigation and mitigation strategies. In this study, the abundance, morphology, color, size and polymer composition of microplastics in surface water of Feiyun River Basin were systematically studied by means of field sampling, microscopy and laser micro-Raman spectroscopy. The result showed that microplastic abundance ranged from 3.7 to 36.4 items/L, with an average of 11.0 ± 2.39 items/L. These microplastics were mainly particles, followed by fragments and fibers, with white, black, and blue being the most common colors. Most of the particles were smaller than 0.1 mm (57%), and a laser micro-Raman spectrometer was used to identify the polymer types of the microplastics. The results showed that the main polymer types identified were PET, PP, and PS. Risk assessment based on PLI, PHI, and PERI indices indicated a low ecological risk of microplastics in the study area. These findings provide further insight into the sources and distribution of microplastics in local watersheds and support future assessments of riverine transport of microplastics to estuarine and marine environments.