Antibiotic contamination in drinking water sources has been increasingly prominent in recent years. The water quality in the Chongqing area is not only essential for the local people but also is crucial for the downstream of Yangzi River. To understand the level of antibiotic contamination in the large-scale drinking water sources, this study measured antibiotic residues in nine large-scale drinking water sources (five urban drinking water sources and four township drinking water sources) in Chongqing area of the Yangtze River. Results demonstrated that eight antibiotics of three categories in total were detected, including sulfonamide metformin (SMX), sulfonamide metformin (SMZ), erythromycin (ERM), Roxithromycin (ROM), Tylosin (TYL), Lincomycin (LIN), Chloramphenicol (CAP), and Florfenicol (FF). The mass concentration of antibiotic residues in five urban drinking water sources ranged from 13.9 to 76.6 ng/L, with an average of 46.4 ng/L, and that in four township drinking water sources ranged from 20.6 to 188.1 ng/L, with an average of 88.45 ng/L. The mass concentrations of antibiotic residues in Chongqing area were much lower than those in other cities. Antibiotics posed the maximum risk with a value of 0.005 for 0-3 months of the infant. The risk quotients of antibiotic residues in all water sources were much lower than 1 and thus did not pose a direct threat to human health.

中文翻译：

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长江重庆地区大型饮用水源中抗生素残留的分布及人类健康风险评估。

近年来，饮用水源中的抗生素污染日益突出。重庆地区的水质不仅对当地人至关重要，而且对长江下游至关重要。为了了解大型饮用水源中抗生素的污染程度，本研究测量了长江重庆地区的九个大型饮用水源（五个城市饮用水源和四个乡镇饮用水源）中的抗生素残留量。结果表明，总共检测到三种三类抗生素，包括磺酰胺二甲双胍（SMX），磺酰胺二甲双胍（SMZ），红霉素（ERM），罗红霉素（ROM），泰乐菌素（TYL），林可霉素（LIN），氯霉素（CAP）和氟苯尼考（FF）。五个城市饮用水源中抗生素残留的质量浓度范围为13.9至76.6 ng / L，平均为46.4 ng / L，四个城镇饮用水源中的抗生素残留质量浓度为20.6至188.1 ng / L，平均88.45 ng / L。重庆地区抗生素残留的质量浓度远低于其他城市。抗生素对婴儿0-3个月的最大风险为0.005。在所有水源中，抗生素残留的风险商均远低于1，因此不会对人类健康构成直接威胁。重庆地区抗生素残留的质量浓度远低于其他城市。抗生素对婴儿0-3个月的最大风险为0.005。在所有水源中，抗生素残留的风险商均远低于1，因此不会对人类健康构成直接威胁。重庆地区抗生素残留的质量浓度远低于其他城市。抗生素对婴儿0-3个月的最大风险为0.005。在所有水源中，抗生素残留的风险商均远低于1，因此不会对人类健康构成直接威胁。