Antibiotics in wastewater treatment plants and receiving waterbodies: Occurrence, Removal and Risks

The widespread presence of antibiotics in wastewater treatment plants (WWTPs) and receiving water bodies has emerged as a critical environmental and public health concern, primarily due to their persistence, ecological effects, and role in the development of antimicrobial resistance (AMR). This review synthesizes quantitative data from 55 studies across 35 countries to assess the occurrence, removal and ecological risks of antibiotics in municipal WWTPs and effluent-receiving water bodies. All major antibiotic classes - including β-lactams, quinolones, macrolides, sulfonamides, and tetracyclines - were consistently detected in influents, effluents, and receiving water bodies, often at concentrations ranging from tens to hundreds of thousands of nanograms per liter. Removal efficiencies exhibited substantial variability, with many WWTPs presenting low or even negative removal rates, underscoring limitations in the existing treatment technologies. Regional disparities were prominent, with Africa, Asia, and South America displaying the highest concentrations and widest variability, reflecting gaps in infrastructure, regulation, and antibiotic stewardship. Although Europe and North America generally exhibited lower contaminant levels, several facilities still reported incomplete removal, demonstrating that performance challenges persist globally. Ecological risk assessments revealed frequent exceedances of predicted no-effect concentrations (PNEC), with high-risk quotients (RQ) > 10 for ciprofloxacin, azithromycin, and sulfamethoxazole in effluents and receiving waters, signifying high-risk hotspots in Africa, Asia, and South America. These findings highlight the urgent need for coordinated action to enhance wastewater treatment performance, develop cost-effective advanced technologies, and strengthen regulatory frameworks.