Research Progress of Microplastic Pollution Status and Risk Assessment of Typical Rivers in China

Abstract

Microplastics (MPs) have received a lot of attention since they were recognized as an emerging pollutant. Rivers transport 80 % of the land's MPs to the oceans. With so many rivers in China, the problem of MPs pollution cannot be ignored. This paper collects data related to MPs in typical rivers in China, summarizes the sources of river MPs, and analyses the status of river MPs pollution and risk evaluation. The results show that riverine MPs mainly originate from sewage treatment plants, surface runoff, atmospheric deposition and plastic breakage. MPs abundance is closely related to population density, with urban rivers having higher MPs abundance than other regions. MPs less than 1 mm in size account for more than 60 % of most rivers. At present, the risk assessment of river MPs is mainly based on three methods, namely, the ecological risk index (PHI), the pollution load index (PLI) and the potential ecological risk index (PERI), and the results of the assessment are mostly low risk. There are differences in the results of the assessment models, which need to be applied jointly with each other for continuous improvement.