Occurrence, distribution and health risk assessment of quinolone residues in cultured fish in southeast China

Quinolone antibiotics are widely utilized in aquaculture, but little is known about the health effects of their residues. This study used UPLC-MS/MS to analyze the distribution of 11 quinolone antibiotics in cultured fish sold in a coastal city in southeast China - Fujian Province and to assess their health risks. The study found 35.77% of 260 cultured fish samples detected quinolones, with three exceeding the MRL and one containing the banned drug ofloxacin. Of the 11 quinolones tested, three were found in cultured fish, with enrofloxacin at up to 246.0 μg kg−1, followed by ciprofloxacin and ofloxacin. The distribution of antibiotic detection rates showed no significant differences across regions or time periods; however, notable variations were observed among different fish species. The dietary exposure assessment revealed that consuming cultured fish does not pose a health risk to residents. Nevertheless, there are still instances that exceed regulatory limits. Therefore, routine monitoring and risk assessment are essential for enhancing regulatory measures and protecting public health.