Urinary antibiotic concentrations in preschool children from eastern China and health risk assessment

Despite limited biomonitoring studies suggesting extensive antibiotic exposure in general population, the body burden of antibiotics in young children and their potential health risks remain unclear. To assess the antibiotic exposure levels in young children, 508 preschoolers aged 3-6 years were recruited from eastern China in 2022, and a total of 50 representative antibiotics from 8 categories, including 17 human antibiotics (HAs), 4 antibiotics preferred as HAs (PHAs), 16 veterinary antibiotics (VAs), and 13 antibiotics preferred as VAs (PVAs), were analyzed by UPLC-MS/MS. Hazard quotient (HQ) and hazard index (HI) were calculated to evaluate the health risks, and multivariate logistic regression was applied to examine diet with antibiotic exposure. Our results showed that there were 41 antibiotics detected in children's urine, and the overall detection frequency was as high as 100%. Sulfonamides, macrolides, β-lactams, quinolones, and azoles were the predominant categories of antibiotic detected. Among the studied children, 6.5% had a sum of estimated daily intake (EDI) of all VAs and PVAs larger than 1 μg/kg/day. Notably, 10.0% of the children had a microbiological HI value exceeding 1, primarily contributed by ciprofloxacin. Children with higher consumption of seafood had a relatively increased exposure to multiple categories of antibiotics, including HAs, VAs, quinolones, azoles, and others. Principal component analysis suggested that "Aquatic products and viscera preferred dietary pattern" scores were positively correlated with the exposure levels of ciprofloxacin (OR: 1.23; 95% CI: 1.02-1.47) and carbadox (OR: 1.32; 95% CI: 1.10-1.59), and a relatively increased exposure of PHAs was realized in children with higher "Meat-egg preferred dietary pattern" scores (OR: 1.24; 95% CI: 1.03-1.50). In conclusion, there was a widespread exposure to antibiotics among preschool children from eastern China, and children who consumed more animal-derived foods may had an increased exposure to antibiotics.