Environmental steroid hormones in aquatic systems: Biogeochemical dynamics, mixture risks, and sustainable mitigation

Abstract

The pervasive occurrence of steroidal sex hormones in aquatic ecosystems poses a substantial challenge to aquatic ecosystem health and may also have implications for public health. Some of these potent endocrine-disrupting chemicals act at ultra-trace concentrations, challenging traditional single-substance toxicological paradigms, and are often incompletely removed by conventional wastewater treatment. This review critically synthesizes the biogeochemical dynamics of aquatic sex hormones, tracing their trajectories from anthropogenic sources through environmental transport, transformation, and persistence. It highlights the need to expand monitoring beyond targeted quantification toward comprehensive steroidal profiling, with particular attention to the potentially overlooked contributions of conjugated forms and uncharacterized transformation products. Furthermore, this review evaluates biological effects through the lens of adverse outcome pathways and the One Health framework, integrating well-established ecological effects in aquatic organisms with the more limited and emerging evidence relevant to human health under real-world mixture exposures. To address these threats, the efficacy and sustainability of advanced and emerging removal technologies are critically assessed, including catalytic oxidation, enzymatic biotransformation, hybrid systems, and nature-based solutions. Ultimately, safeguarding aquatic ecosystems requires an integrated, multi-barrier strategy that combines proactive source control, mixture-aware risk assessment, fit-for-purpose wastewater treatment, and sustainable mitigation aligned with circular economy principles.