The concentration levels of 39 antibiotics, including sulfonamides (SAs), quinolones (QUs), tetracyclines (TCs), macrolides (MLs), and penicillins (PLs), in the surface water of Luoma Lake, and its main inflow rivers were analyzed using SPE-UPLC-MS/MS. The contribution rates of pollution of major rivers entering the lake were analyzed, and the potential ecological and health risks of antibiotics were assessed. The results showed that ρ(antibiotics)in 42 sampling sites was between 30.10 ng·L-1 and 582.37 ng·L-1, and a total of four classes of 23 antibiotics were detected. Among them, the average detection concentration of enrofloxacin (ERX) was the highest (88.05 ng·L-1), and the detection rate of lincomycin (LIN) was the highest (100%). The average concentration of antibiotics in the northern region of Luoma Lake was higher than that in the south, and among the two main rivers entering the lake, Yihe River was the main river contributing to the pollution of antibiotics in Luoma Lake, with a contribution rate of 53.91%. The results of risk assessment showed that ERX had the largest risk quotient. For the cumulative risk quotient (RQcum), RQcum of L6, R30, R31, R32, R33, and R42 was between 0.1 and 1, which is considered medium risk, and RQcum of other points was>1, which is considered high risk. The health risk assessment of 11 antibiotics showed that the health risk quotient (RQH) of adults and children ranged from 4.16×10-6 to 2.46×10-3, and there was no health risk to the human body.
Keywords: Luoma Lake; antibiotics; inflow rivers; occurrence characteristic; risk assessment.