Antibiotic resistance genes (ARGs) in wastewater: Environmental fate and risk mitigation strategies

Antibiotic resistance genes (ARGs) in wastewater systems represent a growing environmental and public health concern, fueled by the widespread and often indiscriminate use of antibiotics in medical, veterinary, and agricultural sectors. This review paper comprehensively examines the environmental fate of ARGs, elucidating their sources, persistence, transport mechanisms, and impacts across aquatic and terrestrial ecosystems. Wastewater treatment plants (WWTPs), though designed to manage conventional pollutants, frequently fail to remove ARGs effectively, thereby functioning as both reservoirs and amplifiers of resistance through microbial interactions and horizontal gene transfer. Effluents and biosolids discharged or applied post-treatment contribute to ARG dissemination in natural environments, where selective pressures from residual antibiotics and environmental conditions promote their persistence and spread. The review further evaluates current and emerging strategies for ARG mitigation, including advanced oxidation processes, membrane filtration, constructed wetlands, and synthetic biology-based interventions. Emphasis is also placed on the integration of artificial intelligence in predictive modeling and biosensing technologies for real-time monitoring. Challenges related to detection methods, regulatory inconsistencies, and infrastructure limitations, especially in low-resource settings, are discussed. Risk assessments reveal serious implications for both human and ecological health, necessitating urgent, multidisciplinary action. Global and local policy initiatives, educational efforts, and coordinated surveillance frameworks are proposed as part of a holistic approach to curbing ARG transmission. By synthesizing recent findings and highlighting future research needs, this review aims to inform and guide effective interventions against the proliferation of antibiotic resistance through wastewater systems.