Risk Threshold and Assessment of Chloramphenicol Antibiotics in Sediment in the Fenhe River Basin, China

Chloramphenicol antibiotics (CAs) are broad-spectrum which widely used in the prevention and treatment of infectious diseases livestock poultry breeding. However, overused CAs can enter watershed eventually sediment. Antibiotics sediment cause secondary pollution through disturbance suspension. In this study, taking Fenhe River Basin as research area, risk were assessed by collecting samples. The results showed that detected all samples Basin. mean concentration was 79.1 μg/kg, thiamphenicol (THI) dominant, up to 58.3 μg/kg. Temporally, there great differences different seasons; higher winter than summer, 4.79–174 times. Spatially, midstream 83.5 upstream downstream. tributaries generally main stream, 1.1 times stream. S2 (Lanhe River) most prominent among sample sites; 190.8 threshold calculated using Equilibrium Partitioning approach (EqP), based on distribution coefficient (Kp) predicted no-effect (PNEC) water, values 0.091–1.44 mg/kg. Based threshold, ecological quotients (RQ). (CHL) Basin, proportion medium-risk areas reached 21.7%, while other low risk. Secondly, 17.4% for THI, Florfenicol (FF) least CAs, low-risk only 8.7%, insignificant