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Greene et al. J Environ Expo Assess 2024;3:12 Journal of Environmental
DOI: 10.20517/jeea.2024.09
Exposure Assessment

Research Article Open Access

A revised and improved toxicokinetic model to
simulate serum concentrations of bioaccumulative

PFAS

Christopher W Greene , Alexander R Bogdan , Helen M Goeden
Health Risk Assessment Unit, Minnesota Department of Health, St. Paul, MN 55164-0975, USA.
Correspondence to: Christopher W Greene, Minnesota Department of Health, 625 Robert St. N, P.O. Box 64975, St. Paul,
MN 55164-0975, USA. E-mail: christopher.greene@state.mn.us

How to cite this article: Greene CW, Bogdan AR, Goeden HM. A revised and improved toxicokinetic model to simulate serum
concentrations of bioaccumulative PFAS. J Environ Expo Assess 2024;3:12. https://dx.doi.org/10.20517/jeea.2024.09

Received: 15 Feb 2024 First Decision: 21 Mar 2024 Revised: 17 Apr 2024 Accepted: 18 Apr 2024 Published: 22 May 2024
Academic Editor: Stuart Harrad Copy Editor: Dong-Li Li Production Editor: Dong-Li Li

Abstract
Minnesota has been grappling with public health issues regarding exposure to per- and polyfluoroalkyl substances
(PFAS) since 2002. For some PFAS, the traditional paradigm for developing health-based water guidance values
(HBGVs) is inadequate due to their tendency to accumulate within the body and to transfer from mother to
newborn via placental transfer and breastfeeding. In 2017, the Minnesota Department of Health (MDH) developed
an Excel-based model to simulate daily serum PFAS concentrations over a lifetime of exposure to facilitate the
derivation of HBGVs for bioaccumulative PFAS. Model results compare favorably to data on breastfed infants, who
represent a susceptible and highly exposed population. Since 2017, new data have emerged that warranted a re-
evaluation of key model parameters. Here, we present a revised and updated version of the 2017 model and assess
the impact of the updates on the model results for perfluorooctanoate (PFOA). Updates to the model’s calculations
and input parameters resulted in a 57% reduction in peak modeled PFOA serum concentrations in 1-year-old
infants compared to the original model. However, the significantly lower epidemiologic-based reference serum
concentration of 0.93 ng/mL (compared to the laboratory animal-based value of 130 ng/mL used in 2017) resulted
in a decrease in the noncancer guidance value from 35 to 0.24 ng/L. Currently available serum PFOA data indicate
that at drinking water concentrations at or below ~1 ng/L, drinking water would not be a major source of PFOA
exposure compared to non-water sources.

Keywords: PFAS, breastmilk, breastfeeding, infants, exposure model, toxicokinetic model, bioaccumulation

© The Author(s) 2024. Open Access This article is licensed under a Creative Commons Attribution 4.0
International License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, sharing,
adaptation, distribution and reproduction in any medium or format, for any purpose, even commercially, as
long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and
indicate if changes were made.

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