Occurrence of typical antibiotics and source analysis based on PCA-MLR model in the East Dongting Lake, China.

The antibiotics residues in freshwater lakes are being highlighted around the world because of high potential threat to environment and human health. Understanding the current state of antibiotics and potential sources in lakes are important. The potential sources of antibiotics (Sewage treatment plants (STPs)), livestock and poultry farms and fishponds in the East Dongting was studied. Compared with other surface water bodies, the concentration of antibiotic in the East Dongting Lake was at a moderate or low level. Ten of 12 antibiotics likely originated from veterinary applications in livestock and poultry farms, especially in swine farms, and concentrations at these sources (ND-1240.41 ng L) were 1-3 orders of magnitude higher than in the effluent of local sewage treatment plants and fishponds. Based on a principal component analysis with multiple linear regression (PCA-MLR) model, we estimated source contributions of 79.95% for livestock and poultry farms, 0.27% for STPs, and 19.79% for aquaculture source and livestock and poultry farms. Overall, the predominance of sulfonamides and livestock and poultry farms in the East Dongting Lake has been identified, which can provide important information for regulating their veterinary use and environmental management.