Exposure of Adults to Antibiotics in a Shanghai Suburban Area and Health Risk Assessment: A Biomonitoring-Based Study

An extensive exposure to antibiotics has been demonstrated in children and pregnant women by biomonitoring, but data from general adults remain limited. In the current study, we studied 822 adults aged 21-75 years in Shanghai in 2017 and analyzed 18 common antibiotics (five veterinary antibiotics (VAs), four human antibiotics (HAs), and nine human/veterinary antibiotics (H/VAs)) in spot urine by liquid chromatography coupled to high-resolution mass spectrometry. All 18 antibiotics were detected in urine with an overall detection frequency of 45.9% and the detection frequency for each ranged from 0.1% to 15.2%. HAs, VAs, H/VAs, and VAs+H/VAs were detected in 4.4%, 11.6%, 38.0, and 44.5% of urine samples, respectively. Adults with the sum of estimated daily exposure dose of all the antibiotics below 1.55 μg/kg/day accounted for 89.1% of adults tested positive. A hazard index value beyond one was seen in 7.2% of adults based on microbiological effect. Ciprofloxacin was the biggest contributor to HI and its hazard quotient value more than one was seen in 5.6% of adults. These findings indicated an extensive exposure to low-dose multiple antibiotics in adults in Shanghai and some adults were at health risk related to the disturbance of gut microbiota.