Department of Biology
Though antibiotic resistance (ABR) represents a major global health threat, contributions of landfill leachate to the life cycle of antibiotics and ABR development are poorly understood in rapidly urbanizing regions of developing countries. We selected one of the largest active landfills in Asia and two landfills that have been closed for 20 years to examine antibiotic occurrences in leachates and associated hazards during wet and dry season sampling events. We focused on some of the most commonly used human antibiotics in Hong Kong, one of the most populous Asian cities and the fourth most densely populated cities in the world. Seven antibiotics (cephalexin [CLX], chloramphenicol [CAP], ciprofloxacin [CIP], erythromycin [ERY], roxithromycin [ROX], trimethoprim [TMP], sulfamethoxazole [SMX]) were quantitated using HPLC-MS/MS generally following previously reported methods. Whereas CLX, CAP, ROX and SMX in leachates did not exceed ABR predicted no effect concentrations (PNECs), exceedances were observed for CIP, ERY and TMP in some study locations and on some dates. In fact, an ABR PNEC for CIP was exceeded in leachates during both sampling periods from all study locations, including leachates that are directly discharged to coastal systems. These findings highlight the importance of developing an advanced understanding of pharmaceutical access, usage and disposal practices, effectiveness of intervention strategies (e.g., leachate treatment technologies, drug take-back schemes), and contributions of landfill leachates to the life cycle of antibiotics and ABR development, particularly in rapidly urbanizing coastal regions with less advanced waste management systems than Hong Kong.
Urbanization, Antibiotic resistance, Predicted no effect concentration, Landfill leachate, Hong Kong
Source Publication Title
© 2018 Elsevier Ltd. All rights reserved.
This work was supported by the General Research Fund of the Research Grants Council, University Grants Committee of Hong Kong (GRF Project no. 12200714). We also thank EPD staff at WENT, SPV and SW landfills for their assistance. However, the funding source and landfill staff had no influence on the study design, collection, analysis and interpretation of data or in the writing of the manuscript or in the decision to submit the article for publication.
Link to Publisher's Edition
Chung, S., Zheng, J., Burket, S., & Brooks, B. (2018). Select antibiotics in leachate from closed and active landfills exceed thresholds for antibiotic resistance development. Environment International, 115, 89-96. https://doi.org/10.1016/j.envint.2018.03.014