Development and\nEvaluation of Aquatic and Terrestrial\nFood Web Bioaccumulation Models for Per- and Polyfluoroalkyl Substances

There is a need for reliable models to predict the food\nweb bioaccumulation\nand assess ecological and human health risks of per- and polyfluoroalkyl\nsubstances (PFAS). This present study presents (i) the development\nof novel mechanistic aquatic and terrestrial food web bioaccumulation\nmodels for PFAS and (ii) an evaluation of model performance using\navailable laboratory and field data. Model predictions of laboratory-measured\nbioconcentration factors and field-based bioaccumulation factors of\nPFAS in fish were in good agreement with observed data as measured\nby the mean model bias (MB), representing systematic over- or under-estimation\nand the standard deviation of the MB, representing general uncertainty.\nThe models provide a mechanistic framework for evaluating the combined\neffect of simultaneously occurring uptake and elimination processes\nand indicate food web-specific magnification of PFAS, with the highest\ndegree of biomagnification occurring in food webs composed of air-breathing\nwildlife. Albumin-water, structural protein–water, membrane-water\ndistribution coefficients, and renal clearance rate are among the\nmost important model parameters. With further development and testing,\nthese models may be useful for future PFAS screening and risk assessment\ninitiatives and advance bioaccumulation studies of PFAS by providing\na mechanistic framework for PFAS bioaccumulation.