长江中游典型饮用水水源中药物的时空分布及风险评价

Spatiotemporal Distribution and Risk Assessment of Pharmaceuticals in Typical Drinking Water Sources in the Middle Reaches of the Yangtze River

采用固相萃取-高效液相色谱/串联质谱方法,分析长江中游典型饮用水水源中药物的季节变化和空间分布;结合风险熵方法,评价其对水生生物的生态风险.结果表明,80%的目标药物在饮用水水源中检出,浓度平均值在0.07~13.00 ng·L^(-1)之间,与国内报道的其他饮用水水源相比,检出浓度处于中等偏低水平.不同药物表现出不同的时空分布,一般冬季的检出水平高于夏季,上下游之间没有显著性差异,可能与药物的季节性/区域性使用排放、流量对稀释作用的影响和温度对生物降解的影响有关.与新冠肺炎疫情前相比,长江中游典型饮用水水源中药物检出浓度较低,原因可能在于疫情防控一定程度上减少药物的使用排放,以及较高的降水量和径流量加强水流的稀释作用.目标药物特别是抗生素对水生生物(特别是藻类)具有中等或低风险,考虑到药物的生态风险、遗传毒性以及抗生素抗性基因的潜在风险,建议加强水环境中药物的调查、评估、治理和管控.

The seasonal variation and spatial distribution of pharmaceuticals in typical drinking water sources in the middle reaches of the Yangtze River were analyzed using the solid-phase extraction and high-performance liquid chromatography-tandem mass spectrometry methods.Combined with the risk entropy method,the corresponding ecological risks for aquatic organisms were evaluated.The results showed that 80%of the target pharmaceuticals were detected in the drinking water sources,with average concentrations of 0.07-13.00 ng·L^(-1).The concentrations of the target pharmaceuticals were lower than or comparable with those in other drinking water sources reported in China.The spatiotemporal distribution of different pharmaceuticals varied.Generally,the detection level in winter was higher than that in summer,and there was no significant difference between that upstream and that downstream.This might be mainly attributed to seasonal/regional use and emissions of the pharmaceuticals,the impact of flow rate on dilution,and the impact of temperature on biodegradation.Compared with those before the COVID-19 epidemic,the detection concentrations of the target pharmaceuticals were relatively low.The reason for this might be that the prevention and control of the epidemic reduced the use and emission of the pharmaceuticals to a certain extent,and the high rainfall and runoff strengthened the dilution of water flow.The target pharmaceuticals,especially antibiotics,posed medium or low risks to aquatic organisms(especially algae).Considering the ecological risks and genotoxicity of pharmaceuticals and the potential risks of antibiotic-resistant genes,it is suggested to strengthen the investigation,evaluation,treatment,and control of pharmaceuticals in the water environment.