The residual antibiotics in the environment have lately caused widespread concerns. However, little information is available on the antibiotic bioaccumulation and its health risk in drinking water resources of South China. Therefore, the occurrence, distribution, and health risk of four quinolone antibiotics including ofloxacin (OFX), norfloxacin (NOR), ciprofloxacin (CIP), and enrofloxacin (ENR) in the Qingshitan reservoir using high-performance liquid chromatography were investigated. Results revealed that the concentrations in water, sediment, and edible fish ranged from 3.49-660.13 ng/L, 1.03-722.18 μg/kg, and 6.73-968.66 μg/kg, respectively. The ecological risk assessment via the risk quotient (RQ) method showed that the values in sediment were all greater than 1, posing a high risk to the environment. The health risk index of water samples was at the maximum acceptable level, with OFX at the top while the rest were at the medium risk level. The main edible fish kinds of the reservoir had high dietary safety and the highest contaminations were found in carnivorous feeding habits and demersal habitat fishes with OFX as the highest magnitude. Source identification and correlation analysis using SPSS showed significant relationships between NOR with pH and turbidity (in water), as well as total phosphor (TP) and total organic carbon (TOC) in sediment. NOR was the highest in sediment which mostly sourced from livestock wastewater, croplands irrigation drain water, and stormwater. Correlations between CIP and ENR with TP were significant, while OFX was positively associated with total nitrogen (TN) which mainly originated from urban sewage as well as directly dosed drugs in fish farms. In conclusion, our results are of great significance for ensuring the safety of drinking water and aquatic products in this region.

College of Environmental Science and Engineering Guilin University of Technology Guilin 541004 China

College of Environmental Science and Engineering Guilin University of Technology Guilin 541004 China Guangxi Key Laboratory of Environmental Pollution Control and Technology Guilin University of Technology Guilin 541004 China

Coordinated Innovation Center of Water Pollution Control and Water Security in Karst Area Guilin University of Technology Guilin 541004 China

Department of Applied Ecology Faculty of Environmental Sciences Czech University of Life Sciences Prague Kamýcká 129 16500 Prague Czech Republic

Fisheries College Ocean University of China Qingdao 266003 China

Guangxi Key Laboratory of Environmental Pollution Control and Technology Guilin University of Technology Guilin 541004 China

School of Environment and Energy South China University of Technology Guangzhou 510641 China Coordinated Innovation Center of Water Pollution Control and Water Security in Karst Area Guilin University of Technology Guilin 541004 China

Sub Campus Depalor Okara University of Agriculture Faisalabad Okara 56130 Pakistan

References provided by Crossref.org