Occurrence and risks of antibiotics in an urban river in northeastern Tibetan Plateau

Yuzhu Kuang,Qian Chen,Si Li,Qiang Gao,Xiaoyu Guo,Jingrun Hu,Xi Yang,Ruijie Zhang,Weiling Sun

doi:10.1038/s41598-020-77152-5

Abstract

There is a dearth of information on the occurrence and risks of antibiotics in the urban rivers from plateau areas. This study investigated 83 antibiotics in water and sediments of an urban river and effluents of sewage treatment plants (E-STPs) in Xining, Qinghai (northeastern Tibetan Plateau). Fifty-three antibiotics were detected, and the concentrations of individual antibiotics varied in the range of undetected (ND)-552 ng/L in water, ND-164 ng/g in sediments, and ND-3821 ng/L in E-STPs. Seasonal differences of antibiotic concentrations were significant for water samples (p < 0.05) but insignificant for sediments (p > 0.05). In urban area, E-STP is the main source of antibiotics in the river, while runoff from manured cropland contributes partially to antibiotics in the river in the suburban area. The antibiotic compositions in water were different from those in sediments, but were similar to those in E-STPs. Notably, because of strong solar radiation and long sunshine hours in the plateau area, low levels of quinolones, which are sensitive to photolysis, were observed in river water. Moreover, norfloxacin and enrofloxacin, observed in urban river from other regions of China, were not detected in the Huangshui River water. The occurrence of ofloxacin, erythromycin, roxithromycin, clarithromycin, and trimethoprim in E-STPs may induce a possible risk to antibiotic resistance evolution. Trimethoprim, anhydroerythromycin, sulfamethoxazole, sulfapyridine, and clindamycin in river water could pose low to medium risks to aquatic organisms. Further investigation on the occurrence and distribution of antibiotic resistance genes in the Huangshui River is urgently needed.

Highlights

Antibiotics are primarily used to treat and prevent human and animal diseases, as well as growth promoters and feed efficiency improvers in agriculture and animal husbandry[1,2]
This study investigated the occurrence of 83 antibiotics in water and sediments of the Huangshui River, and effluent of sewage treatment plants (STPs) (E-STPs) discharged into the river
This study investigated 83 antibiotics in water and sediments from the Huangshui River, and E-STPs in Xining, Qinghai, in the northeastern Tibetan plateau

Summary

Introduction

Antibiotics are primarily used to treat and prevent human and animal diseases, as well as growth promoters and feed efficiency improvers in agriculture and animal husbandry[1,2]. The concentrations of individual antibiotics could be up to 2702 ng/L and 449 ng/g in urban river water and sediments, respectively, heavily polluted by domestic s ewage[13]. Xining is the capital of Qinghai province, with a total population of 2.355 million It is located in the climatically sensitive semiarid zone, northeastern Tibetan Plateau, with an average altitude of 2275 m. This study investigated the occurrence of 83 antibiotics in water and sediments of the Huangshui River, and E-STPs discharged into the river. The objects of this study are (1) to investigate the occurrence and spatiotemporal distribution of antibiotics in the Huangshui River and E-STPs, (2) to compare the regional differences of antibiotic concentrations in urban rivers of China, and (3) to evaluate the possible risk of antimicrobial resistance development and potential ecological risks of antibiotics in the Huangshui River. The results provide useful information on the management of antibiotic pollution in urban rivers

Methods

Results

Conclusion