Distribution characteristics of selected antibiotics in urban water supply systems in 5 southern cities and their potential health risk analysis

Objective The typical antibiotics in drinking water were determined to evaluate the distribution characteristics and health risk of antibiotics in urban water supply systems.

Methods The source water, finished water and tap water were collected from 5 drinking water treatment plants located in south China.The 48 kinds of antibiotics in water were detected by methods of solid-phase extraction (SPE) and ultra-performance liquid chromatography-tandem mass spectrum (UPLC-MS/MS).Risk Quotients were calculated to assess the health risk of antibiotics pollution in the drinking water.

Results Totally 15 antibiotics were detected in the source water, and the total concentrations were in range of 63.31-114.74 ng/L (average level was 85.27 ng/L).Six antibiotics were detected in the water supply systems, and the total concentrations were in range of 0.86-7.15 ng/L (average level was 2.96 ng/L) in the finished water, and the total concentrations were in range of 0-8.08 ng/L (average level was 2.96 ng/L) in the tap water.The water-treatment processes of chlorine disinfection could efficiently remove 96.52% antibiotics, and β-lactams, lincosamides and sulfanilamides could be removed completely.The total health risk caused by antibiotics in drinking water supplied by these plants was very low.

Conclusion Only a trace number of antibiotics were detected in the water supply plant, which won't cause obvious health hazard to the human body.