Water quality for agricultural reuse: integrating risk assessment, governance, and sustainable implementation for resilient food systems

Global freshwater scarcity, climate change, and rising food demand have intensified the need for sustainable agricultural water management. Wastewater reuse has emerged as a strategic solution, alleviating water stress, enhancing climate resilience, and supporting circular resource management. However, the long-term sustainability of agricultural water reuse depends critically on water quality that safeguards crop productivity, ecosystem integrity, and public health. This review provides a novel interdisciplinary synthesis by integrating conventional indicators (salinity, nutrients, microbial pathogens) with emerging contaminants (pharmaceuticals, per- and polyfluoroalkyl substances [PFAS], microplastics, antibiotic resistance genes). Unlike previous reviews focused narrowly on treatment or regulation, we combine Quantitative Microbial Risk Assessment (QMRA), chemical and ecological risk evaluation, and AI-assisted multi-criteria decision analysis (AI-MCDA) into a unified framework. We systematically surveyed peer-reviewed literature (Scopus, Web of Science, ScienceDirect, 2010–2025) and international guidelines (WHO, FAO, EU, US EPA, ISO), highlighting both progress and persistent gaps in harmonizing standards. Advances in monitoring technologies IoT sensors, biosensors, remote sensing, and digital twins are critically assessed for their role in real-time surveillance and adaptive governance. Case studies from the Middle East, North Africa, Europe, Australia, the United States, China, and India illustrate diverse adoption pathways shaped by institutional capacity, economic feasibility, and public acceptance. Finally, we identify specific knowledge gaps, including limited long-term field data on contaminant accumulation, inadequate regulation of PFAS and microplastics, and insufficient integration of AI into risk governance. Future research directions emphasize harmonized monitoring protocols, interdisciplinary One Health approaches, and embedding reuse within the Water–Energy–Food Nexus. By linking water quality monitoring, risk assessment, governance, and sustainable implementation, this review advances a comprehensive framework for safe and resilient agricultural water reuse in support of global food security and climate adaptation.