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Seasonal distribution characteristics and health risk assessment of typical antibiotics in the Harbin section of the Songhua River basin.

Research paper by Weihua W Wang, Wanfeng W Zhang, Hong H Liang, Dawen D Gao

Indexed on: 08 Mar '18Published on: 08 Mar '18Published in: Environmental technology



Abstract

A method was established for coupled solid phase extraction-ultra performance liquid chromatography and mass spectrometry, to simultaneously detect 12 common antibiotics belonging to 4 types (sulfonamides, macrolides, fluoroquinolones and cephalosporins) in surface water environments. The characteristic distribution and seasonal variation in antibiotic content was investigated in the Harbin section of the Songhua River basin, Northeastern China. The results showed that the 12 antibiotics monitored were all detected to varying degrees, with 100% detection rates for sulfamethoxazole (SMX), cefazolin (CFZ), ofloxacin (OFL), flumequine (FLU), azithromycin (AZI) and roxithromycin (ROX) in all sampling sites. SMX and CFZ were found to be representative antibiotics, with high detection concentrations of 1.80-73.1 ng Land 1.2-65.4 ng L, respectively. The seasonal variation in antibiotic concentrations showed the highest levels in winter, lowest in summer, with no significant difference between levels in spring and autumn. The total concentrations of all 12 antibiotics in spring, summer, autumn and winter, were 39.7, 9.6, 27.5 and 136.2 ng L, respectively. Seasonality was also observed in antibiotic distribution along the riverbank, with winter concentrations of all antibiotics detected upstream of the Harbin section being lower than the downstream section; in summer, except for CFZ, the concentrations of all antibiotics detected were higher upstream, than downstream of the Harbin section. Finally, the health risks to people of different ages caused by residual antibiotic contamination in the Songhua River were evaluated using the risk quotients (RQs) method. Results showed that the risk of antibiotics was far lower than 1, with no direct threat to human health established; however, the long-term risk deserves further evaluation.