Antibiotic Exposure in School Children in Tropical Environments: Impact of Dietary Habits and Potential Health Risks

Due to their wide application, there is a large amount of residual antibiotics in our environment and food, raising concerns about health risks to children. In this study, 302 primary-school students in Hainan Province, China, were recruited to collect urine samples and questionnaires. The internal exposure levels of sixteen antibiotics and three metabolites in urine were determined by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), and the contents of DNA oxidative damage markers, 8-hydroxy-2'-deoxyguanosine (8-OHdG) and lipid peroxidation marker malondialdehyde (MDA), were also measured. Antibiotics and their metabolites were frequently detected, with a total concentration of < LOD-4.58 × 10³ ng/mL. Binary logistic regression analysis revealed that the detection frequency of DFs of antibiotics was associated with animal-derived foods, such as red meat with fluoroquinolones (FQs) (OR = 76.4, 95% CI 1.68-3479), poultry with norfloxacin (NFX) (OR = 6.56, 95% CI 1.08-39.9), and aquatic products with ciprofloxacin (CIP) (OR = 3.96, 95% CI 1.32-11.9). Cumulative risk assessment based on microbial effects showed a hazard index of 3.5 for children, mainly driven by azithromycin (45.6%), oxytetracycline (18.1%), and CIP (33.9%). Multiple linear regression indicated that lipid peroxidation was significantly associated with high quantiles of three antibiotic classes, while DNA oxidation was positively correlated with all antibiotic classes except FQs. These findings indicate that children in Hainan are widely exposed to antibiotics. Although the exposure levels are generally low, chronic low-dose antibiotic exposure may contribute to disease development and oxidative stress damage.