Emerging contaminants threaten global water security and demand planetary-health-informed monitoring, treatment and governance solutions

Water systems in the Anthropocene are under unprecedented pressure from a diversifying array of emerging contaminants (EC), including pharmaceuticals, per- and polyfluoroalkyl substances (PFAS), microplastics, pesticides and endocrine-disrupting compounds, whose persistence, low-dose bioactivity and mixture effects challenge conventional water-quality paradigms. This review synthesizes literature published between 2020 and 2026 to examine the occurrence, transport and fate of EC and their ecological and human health implications through the lens of planetary health, a framework that explicitly links the stability of Earth's natural systems to human wellbeing. We also evaluate advances in screening analytics, sensor networks and machine-learning-enabled monitoring, alongside the emergence of Digital Twins as tools for predictive, adaptive water management. We further assess advanced treatment technologies, including advanced oxidation processes, membrane filtration and nanomaterial-based adsorbents within circular water management strategies that seek to recover water, energy and nutrients rather than treat wastewater as waste. This review situates the technical advances against the backdrop of planetary boundary transgression, climate-driven shifts in contaminant fate and the Sustainable Development Goals, particularly SDG 6 (clean water and sanitation) and SDG 3 (good health and wellbeing). We conclude by identifying critical research gaps, including the need for full-scale and low-resource-setting validation of AI-enabled monitoring, insufficient mixture-toxicity and transformation-product data, and the need for harmonized regulatory frameworks, and propose an integrated research agenda that couples analytical innovation, digital infrastructure and treatment engineering with planetary health governance.