An Assessment of Microplastic Pollution in Several Streams of Gyeonggi-do

In recent years, there has been a growing interest in the environmental effects of microplastics, leading to active research efforts worldwide. However, most of these studies have focused on microplastic pollution in marine environments, resulting in a lack of information on the levels of microplastics in freshwater environments. To address this gap, this study investigated types and concentrations of microplastics in four rivers and two effluents from wastewater treatment plants in Gyeonggi-do, Korea, to determine the extent of microplastic contamination in relation to the surrounding environment and seasons. Microplastic concentrations were higher in the Gyeongan Stream (1.8~9.9 ea/L), Bokha Stream (0.47~2.6 ea/L), Osan Stream (0.5~6.6 ea/L), and Tan Stream (0.2~11.4 ea/L) than in the Tan Stream or Nakdong River, which were investigated in the past. However, due to spatial limitations, it is unclear whether the wastewater effluent had any downstream effects. The most commonly detected microplastic types were polypropylene, polyethylene, and polyester, comprising 58–90% of total microplastics, likely due to the influence of the surrounding environment (industries and human habitation). Moreover, types and concentrations of microplastics were found to reflect seasonal characteristics, particularly rainfall, suggesting that continuous monitoring is necessary to accurately assess the situation. The findings of this study can aid in the development of management strategies for reducing microplastic pollution in freshwater sources in the future.