[Abundance and Physicochemical Characteristics of Microplastics in Surface Water and Sediments of Different Types of Waters in China].

， respectively. Among all lakes， the abundance of microplastics in lakes in the eastern and western regions was higher than that in the central region. In river systems， the Yellow River and Songhua River systems showed higher average microplastic abundance in surface waters compared to that in other river systems， whereas the Huaihe River and Haihe River systems demonstrated relatively higher levels in sediments. For marine environments， the South China Sea and Yellow Sea contained elevated microplastic abundance compared to that in the Bohai Sea and East China Sea. The abundance of microplastics was significantly positively correlated with the gross regional product， the total output value of industry， the total output value of agriculture， the total output value of fisheries， population， and sewage discharge. Microplastics smaller than 1 mm predominated in both surface waters and sediments， with transparent or colorless microplastics being the most prevalent. Fibers and fragments represented the most common morphological types， while polyethylene， polypropylene， and polyethylene terephthalate constituted the predominant polymer categories. However， the research areas of microplastics in China's waters are insufficiently covered. In summary， microplastics are widely distributed in China's water bodies and exhibit significant spatial heterogeneity. Their abundance and physicochemical characteristics are closely related to human activities. This study provides theoretical support for the control of microplastic pollution in water bodies and the analysis of the impact of human activities on their abundance.