Lorenzo Ricolfi , Yefeng Yang, Patrice Pottier , Kyle Morrison, Coralie Williams, Pietro Pollo, Daniel Hesselson, Gregory Neely, Matthew D. Taylor, Shinichi Nakagawa, Malgorzata Lagisz

Per- and polyfluoroalkyl substances (PFAS) threaten ecosystems worldwide due to their persistence, bioaccumulation, and toxicity. Through a global-scale meta-analysis of 122 aquatic and terrestrial food webs from 64 studies, we analyse 1,009 trophic magnification factors (TMFs) for 72 PFAS and identify key variability drivers. PFAS concentrations systematically doubled with each trophic level increase (mean TMF=2.00, 95% CI:1.64-2.45), confirming widespread biomagnification across ecosystems. Methodological disparities across studies emerged as the dominant source of TMF variability. Our models explained 84% of the variation in TMFs, underscoring predictive capacity. Notably, the industrial alternative F-53B exhibited the highest magnification (TMF=3.07, 95% CI:2.41-3.92), a critical finding given its expanding use and minimal regulatory scrutiny. This synthesis establishes PFAS as persistent trophic multipliers and provides a framework to prioritise high-risk compounds and harmonise biomagnification assessments. Our results call for consideration of stricter PFAS regulation to curb cascading ecological and health impacts.