长江口微塑料时空分布及风险评价

There has been a recent focus on microplastics (<5mm) because of their presence in different environmental media. The spatial and temporal distribution of microplastics in the surface sediments of the Changjiang Estuary were investigated in March and July 2017. Sampling was conducted at 17 stations covering the north passage and south passage of the Changjiang Estuary, East China Sea and Hangzhou bay. Among these sampling stations, the highest concentration of microplastics was (39.33±14.34) particles/kg (DW) in the Hangzhou bay in summer. There was no significant difference in spatial distribution of microplastics. The amount of precipitation was highly related with the abundance of microplastics, which showd higher concentrations in summer than in spring. The size, color, shape and composition of microplastics were classified. Attenuated total reflectance-Fourier transform infrared spectrometry showed that there were several types of microplastics existing in sediments, including polyethylene, polypropylene, polyvinyl chloride, polyamide, and polystyrene, among them, polyethylene was the main type. The method of pollution load index was used to assess the degree of microplastic pollution. Overall, the Changjiang Estuary-Hangzhou bay and its adjacent areas were less polluted by microplastics.