Antibiotic residues in commercial freshwater fish from southeast China: distribution and human health risk assessment.

We investigated 14 antibiotic residues in 8 marketed freshwater fish species from southeast China and estimated the associated health risks to local consumers. The antibiotic residues were determined by UPLC-MS/MS. Our findings revealed widespread distribution of quinolones (QNs), tetracyclines (TCs), and chloramphenicols (CAPs) in the freshwater fish. Notably, the average concentrations of enrofloxacin and ciprofloxacin reached levels as high as 62.5 μg/kg wet weight (ww) and 11.7 μg/kg ww, respectively, and detection frequencies were 68.7% for enrofloxacin and 31.6% for ciprofloxacin. Additionally, we detected chloramphenicol, a prohibited antibiotic, in samples with a detection frequency of 0.76%. Among the fish species, the mean concentration of total antibiotic residues was highest in bluntnose black bream (263.3 μg/kg), followed by English perch (52.4 μg/kg), crucian carp (46.3 μg/kg), black carp (28.6 μg/kg), yellowcheek carp (21.0 μg/kg), grass carp (15.3 μg/kg), bighead carp (3.78 μg/kg), and mandarin fish (3.69 μg/kg). We estimated the daily intake values of these antibiotic residues which were lower than the acceptable daily intake values and hazard indexes were much less than 1. It indicates that there is very low direct health risk to consumers. Despite that, investigation on the chronic impact, such as antibiotic-resistant bacteria, gut microbiota disruption, and allergic reactions, is urgently needed.