长江流域重要水源地微塑料赋存特征及生态风险评估OA

As emerging contaminants,microplastics have garnered considerable attention because of their potential risks to both ecosystems and human health.In October 2022,the Ministry of Water Resources issued a list of nationally important drinking water sources in the Yangtze River Basin,imposing higher standards for their protection and safety.However,there is currently limited research specifically focusing on microplastics in drinking water sources,and knowledge of their ecological risks in critical environments remains insufficient.This study focused on 12 important drinking water sources located in the upper,middle,and lower reaches of the Yangtze River Basin in China.The occurrence characteristics of microplastics in these water bodies were analyzed using Fourier-transform infrared(FTIR)imaging microscopy and optical microscopy.Furthermore,the ecological risk of microplastics in water bodies was assessed using a potential ecological risk index.The results revealed that the abundance of microplastics in the water of all water sources ranged from 0 to 4 pieces∙L-1,with an average abundance of 1.8 pieces∙L-1,which was lower than the average level of microplastics in water of the Yangtze River Basin.The microplastics detected in the drinking water source were predominantly fibrous in shape(57.1％),transparent in color(42.9％),and mainly composed of polyethylene(PE,47.6％)and polypropylene(PP,28.6％)in terms of polymer composition.The ecological risk assessment of microplastics in drinking water sources indicated that among the nine water sources detected with microplastics,two belonged to risk zone Ⅳ,primarily due to polyvinyl chloride(PVC)pollution,one belonged to risk zone Ⅱ,and six belonged to risk zone I,with low ecological risk.This study contributes to the understanding of current state of microplastic pollution in important drinking water sources in the Yangtze River Basin and provides a scientific basis for ensuring drinking water safety and ecological protection.