Development and Evaluation of Aquatic and Terrestrial Food Web Bioaccumulation Models for Per- and Polyfluoroalkyl Substances

There is a need for reliable models to predict the food
web bioaccumulation
and assess ecological and human health risks of per- and polyfluoroalkyl
substances (PFAS). This present study presents (i) the development
of novel mechanistic aquatic and terrestrial food web bioaccumulation
models for PFAS and (ii) an evaluation of model performance using
available laboratory and field data. Model predictions of laboratory-measured
bioconcentration factors and field-based bioaccumulation factors of
PFAS in fish were in good agreement with observed data as measured
by the mean model bias (MB), representing systematic over- or under-estimation
and the standard deviation of the MB, representing general uncertainty.
The models provide a mechanistic framework for evaluating the combined
effect of simultaneously occurring uptake and elimination processes
and indicate food web-specific magnification of PFAS, with the highest
degree of biomagnification occurring in food webs composed of air-breathing
wildlife. Albumin-water, structural protein–water, membrane-water
distribution coefficients, and renal clearance rate are among the
most important model parameters. With further development and testing,
these models may be useful for future PFAS screening and risk assessment
initiatives and advance bioaccumulation studies of PFAS by providing
a mechanistic framework for PFAS bioaccumulation.