Bioaccumulation Characteristics of Quinolones (QNs) in Dominant Fish Species and Their Correlation with Environmental Factors in Baiyangdian Lake

In recent years, quinolone antibiotics (QNs), which easily bioaccumulate in aquatic organisms, have been widely detected in lake ecosystems, and the bioaccumulation and trophic transfer behavior are obviously spatiotemporally different. In this study, the bioaccumulation and trophic transfer behavior of fourteen QNs in nine dominant fish species were studied, the correlation with environmental factors was analyzed, and the health risk of QNs was evaluated in Baiyangdian Lake. The results showed that the mass concentrations of ∑QNs in water varied from 0.7400 to 1590 ng·L-1. Furthermore, the detected frequencies of flumequine (FLU), oxolinic acid (OXO), and ofloxacin (OFL) were higher, and the average mass concentration of FLU was the highest. The content of ∑QNs in fish ranged from 17.1 to 146 ng·g-1, and the average contents of ciprofloxacin (CIP) and OFL were higher. The bioaccumulation factors (BAF) were in the range of 96.2 (BAFMAR)-489 (BAFCIP) L·kg-1, indicating the bioaccumulation of QNs was low in dominant fish species. The trophic magnification factors (TMF) of five QNs (enrofloxacin (ENR), FLU, marbofloxacin (MAR), norfloxacin (NOR), and OFL) varied from 0.714 (TMFMAR) to 1.33 (TMFENR), indicating ENR exhibited trophic magnification, while FLU, MAR, and ∑QNs exhibited trophic dilution. The results of correlation analysis between environmental parameters and BAF/TMF showed that pH, T, SD, DO, COD, TP, TN, NH4+-N, NO3--N, and PO43--P were significantly related to the bioaccumulation of QNs in fish. The results of human health risk showed that the hazard quotient (HQ) of CIP (0.0040-0.026) was significantly higher than that of other QNs (≤ 0.0050), and the hazard indices (HI) ranged from 0.0010 to 0.035, indicating a high level of health risk. Therefore, to reduce the health risk, the standard and residue limits of QNs should be set in Baiyangdian Lake.