Occurrence, removal efficiency, and ecological risk assessment of antibiotics in drinking water sources in Wuhan
- VernacularTitle:武汉市饮用水源抗生素污染特征、去除效能及生态风险评估
- Author:
Qin WANG
1
;
Yixuan WANG
1
;
Pei WANG
1
;
Qing HAN
1
;
Yonghua XIAO
1
Author Information
- Publication Type:Investigation
- Keywords: antibiotics; source water; finished water; conventional treatment process; ecological risk assessment
- From: Journal of Environmental and Occupational Medicine 2026;43(9):1132-1138
- CountryChina
- Language:Chinese
- Abstract: Background Antibiotics are frequently detected in aquatic environments, posing potential threats to ecological systems and public health. Objective To characterize antibiotic contamination in source water in Wuhan, evaluate the removal efficiency of conventional drinking water treatment processes, identify potential pollution sources, and assess ecological risks, thereby providing evidence to support water safety management. Methods A total of 34 source water samples and paired finished water samples were collected. Twenty-seven target antibiotics were analyzed via solid-phase extraction coupled with high-performance liquid chromatography-tandem mass spectrometry. Total antibiotic concentrations and the relative contributions of individual antibiotics were calculated for each sampling site. Differences in removal performance across seasons and waterworks scales were further assessed. Antibiotic pairs with co-occurrence frequencies of ≥ 10 were included in Spearman’s rank correlation analysis to explore co-occurrence patterns. Potential sources were inferred according to their approved clinic and veterinary uses. For ecological risk assessment, predicted no-effect concentrations were derived from chronic toxicity values for fish, Daphnia, green algae, and mysid obtained from the ECOSAR database. Risk quotients (RQ) were calculated using both the median and the 95th percentile concentrations to characterize typical and high-end ecological toxicity. Results Seventeen antibiotics were detected in the source water. Lincosamides, macrolides, and sulfonamides were frequently detected, with detection frequencies exceeding 50%. Although quinolones were detected less frequently (2.94%-38.24%), they exhibited episodic high concentrations; the 95th percentile concentration of cinoxacin (CNX) reached 365.73 ng·L−1. The mean total antibiotic concentration was 1.79 times higher in the wet season (105.97 ng·L−1) than in the dry season (59.21 ng·L−1). The contribution of quinolones increased markedly from 0.87% in the dry season to 43.10% in the wet season. Except for flumequine (FQ), ofloxacin (OFX), enoxacin (ENX), and clarithromycin (CLR), the median removal rates of the remaining antibiotics by conventional treatment processes all exceeded 80%. Ten antibiotics achieved complete removal (100%) in the wet season, compared with 4 antibiotics in the dry season. The median removal rate of CLR declined with decreasing waterworks scale, from 67.92% in large-scale plants to –1.96% in medium-scale plants and –71.25% in small-scale plants. Apparent negative removal was observed for sulfadiazine (SDZ), FQ, OFX, and CLR, with OFX exhibiting the highest frequency of negative removal events (n=14). Correlation analysis revealed significant positive correlations between sulfonamides and macrolides (ρ=0.52-0.83), indicating mixed influences from livestock farming and domestic wastewater. Lincomycin (LIN) was positively correlated with sulfamethoxazole (SMX), but negatively correlated with the aforementioned antibiotic network, suggesting a predominantly human medical source. Based on median concentrations, the ecological risk of individual antibiotics was negligible. However, the cumulative risk to Daphnia reached a low level (RQ > 0.01), with sulfonamides contributing more than 70% of this risk. Based on the 95th percentile concentrations, bost individual and cumulative risks of quinolones to fish and Daphnia increased to low levels, with quinolones contributing more than 55% of the total risk. Conclusion Antibiotics are commonly detected in source water in Wuhan, and conventional drinking water treatment dose not completely eliminate all target compounds. Quinolones, despite their relatively low detection frequencies, occur at episodically high concentrations and pose low risks to fish and Daphnia under high-end exposure scenarios, warranting priority control. The coexistence of human-use and veterinary-use antibiotics reflects diverse pollution sources and highlights the need for coordinated multi-source pollution control.
