[Distribution Characteristics and Risk Analysis of Antibiotic in the Groundwater in Beijing]

Based on the GC-MS technique, we conducted a survey to investigate the concentration, distributions, and emission sources of sulfonamides (SAs), fluoroquinolones (FQs), tetracycline (TCs), β-lactam, and macrolides in groundwater in Beijing. Results indicated that SAs, FQs, and TCs were the main types of antibiotic in groundwater, and the detection ratios of trimethoprim, ciprofloxacin, and norfloxacin were above 70%. Concentration of antibiotics in sites from sewage irrigation areas were significantly higher than those from the drinking source area or the south-to-north water recharge areas. The highest concentration of sulfadimidine (236 ng·L^-1) and sulfadiazine (96.8 ng·L^-1) in groundwater were both found in the sewage irrigation area. An ecological risk analysis showed a low risk for antibiotic in groundwater at drinking source sites, while groundwater at sewage irrigation sites fell into the high risk group. It is important to strengthen the ciprofloxacin monitoring and ensure underground water safety.