Trophic transfer of per- and polyfluoroalkyl substances in aquatic ecosystems

Per- and polyfluoroalkyl substances (PFAS) pose a widespread environmental concern due to their persistence, bioaccumulation potential, and toxicity. Their capacity to biomagnify poses a potential threat to ecosystem stability and human health. However, biomagnification is not an inevitable outcome but rather a conditional consequence of complex toxicokinetic processes interacting with environmental conditions. This review systematically summarizes the current understanding of the trophic transfer of PFAS in aquatic ecosystems, employing the trophic magnification factor as a central tool for standardized assessment. It reveals that biomagnification is related to the specific compound and organism, and is influenced by food web structure and environmental conditions. While legacy long-chain PFAS often demonstrate the capacity to biomagnify, emerging alternatives and precursors exhibit a more variable and uncertain relationship. Future research should shift towards assessing complex mixtures, accounting for precursor transformation, and integrating species-specific physiological ecology with toxicokinetics. The development of predictive models that can integrate mechanistic and food web structures is crucial for accurate risk assessment and for formulating effective, targeted management strategies to protect both aquatic ecosystems and human health.