Occurrence, ecological, and health risk assessment of antibiotics in water from the Karst River during influenza season

Abstract

The widespread use of antibiotics has significantly increased their presence in aquatic environments, particularly in sensitive Karst River systems. In this study, the distribution and ecological, human health, and resistance selection risk assessment of 44 antibiotics in the typical Karst River, Lijiang River, were investigated during the influenza season, a period marked by heightened antibiotic usage. 27 antibiotics could be found in the water of Lijiang River, among which azithromycin showing the highest concentrations. The concentrations of total antibiotics were in the range 171.70–2003.75 ng/L, with an average value of 704.76 ng/L. Macrolide was the predominant class, constituting an average of 57.65% of the total antibiotic concentrations. Risk assessments revealed that certain antibiotics, especially macrolides, posed moderate to high ecological risks to algae, displayed potential human health risks at low levels and contributed to antimicrobial resistance. Among all the antibiotics, azithromycin was the only one could cause ecological risk to algae, human health risk towards infants and antimicrobial resistance selection risk, which should be identified as the priority antibiotic for control in the Lijiang River during the influenza season. There was no difference in the concentrations, human health and antimicrobial resistance selection risk of antibiotics between mainstream and tributaries of Lijiang River. This study contributes to a better understanding of antibiotic pollution and provides insights into potential risk management practices in vulnerable aquatic systems worldwide.