Microplastic Pollution Status of Major Highland Agricultural Watersheds in Gangwon

In South Korea, various local governments, including Seoul, Incheon, Gyeonggi, Gyeong sang, and Joella, are proactively assessing the extent of microplastic pollution in freshwater. In contrast, microplastic pollution research in Gangwon Special Self-Governing Province is lacking. To address this, in this study, sampling was undertaken in Hongcheon and Jeongseon, along with in highland agricultural watersheds, which are major sources of non-point source pollution. Microplastic analysis of the samples was conducted using a micro-Raman spectrometer. During non-rainy periods, microplastic concentrations in river samples were approximately 13-438 particles/L and 40-452 particles/L in Hongcheon and Jeongseon, respectively. During rainy periods, the concentrations were approximately 67-313 particles/L and 98–103 particles/L in Hongcheon and Jeongseon, respectively. The types of microplastics detected in the samples included polyethylene, polypropylene, polystyrene, polyvinyl chloride, and polyethylene terephthalate, with polyethylene and polypropylene being the most prevalent. From this study, a database on microplastic pollution levels and types present in the highland farming watersheds of Gangwon was established.