Comprehensive survey and health risk assessment of antibiotic residues in freshwater fish in southeast China

To assess the health risks from antibiotic residues in freshwater fish, this study analyzed residues of 65 antibiotics in 10 freshwater fish species sampled in southeast China. Eight antibiotics were detected by UPLC-MS/MS at an overall detection rate of 53.9 %, with 3.48 % of samples exceeding MRLs and 13.0 % suggesting the misuse of human antibiotics. Quinolones, particularly enrofloxacin, were the most frequently detected residues. Azithromycin, an antibiotic intended only for human use, was detected at a rate of 14.8 % at concentrations up to 453.1 µg/kg. Antibiotic residues varied in category and concentration across freshwater fish species. Residues were detected in benthic predatory fish at higher levels than in middle or upper omnivorous or herbivorous fish. Estimated daily intakes showed that the consumption of cultured fish from this region does not pose a serious risk to human health, the hazard index being less than one. However, these findings suggest that the abuse of antibiotics in aquaculture is still a problem, and more attention should be paid to their residues in fish to enhance food safety.