Distribution characteristics, driving factors, and ecological health risk assessment of antibiotics in surface water of the Yangtze River Basin

This study systematically collected and analyzed the concentration data of antibiotics in surface water of the Yangtze River Basin from 2012 to 2023. It analyzed the distribution characteristics of antibiotics in the surface water of the river basin, explored the impact of socio-economic factors on antibiotic distribution, and used the risk quotient (RQ) and joint probability curve (JPC) methods to evaluate their ecological risks. At the same time, the health risk quotient method was used to evaluate health risks. The results revealed that a total of 67 antibiotics were detected in surface water of the Yangtze River Basin from 2012 to 2023. The number of antibiotics in the water increased from 51 in the upstream to 62 in the downstream, and there were significant spatial differences in antibiotic pollution. Specifically, sulfonamides showed high concentrations in the upstream and downstream, quinolones in the middle and downstream, tetracyclines in the middle, and macrolides in the upstream and middle, respectively.The distribution of antibiotics in surface water of the Yangtze River Basin was related to fisheries, per capita GDP, urbanization rate, and medical level. The assessment combining the RQ and JPC methods indicated that particular attention should be paid to the ecological risks of antibiotics such as tetracycline, chlortetracycline, enrofloxacin, ofloxacin, clarithromycin, and lomefloxacin. Meanwhile, the health risk quotient method indicated that the vast majority of antibiotics in the water sources of the Yangtze River Basin posed negligible risks to human health. However, tetracycline and ofloxacin in the middle reaches of the Wuhan water source in 2021 showed a Low Risk, while in the downstream Jiangsu water source, the health risk quotient of ciprofloxacin reached 10⁻¹, indicating a Moderate Risk and should be given close attention.