Using Dose-Additive Models To Predict Exposure and Effects of a Military Site Risk-Relevant PFAS Mixture in Mice

Area of Science:

• Environmental Science
• Toxicology
• Ecotoxicology

Background:

• Per- and polyfluoroalkyl substances (PFAS) are pervasive environmental contaminants often found as mixtures.
• Current ecological risk assessments typically focus on individual PFAS, hindering understanding of mixture effects.

Purpose of the Study:

• To investigate the exposure and toxicological effects of individual and mixed PFAS relevant to environmental media and firefighting foams.
• To evaluate the efficacy of dose addition methods for predicting PFAS exposure and effects in ecological risk assessments.

Main Methods:

• CD-1 mice were exposed to individual PFAS and relevant mixtures.
• Whole-body and tissue (serum, liver, kidney, brain) PFAS concentrations were measured.
• Organ weights, clinical chemistry, and mixed-effect models were used to assess toxicological effects and predictive relationships.

Main Results:

• Dose addition methods successfully predicted PFAS exposure and liver effects.
• A PFOS-relative weighting factor showed potential for predicting effects.
• Applying findings to a desktop assessment indicated difficulty in differentiating reference from impacted sites based solely on dietary PFAS changes.

Conclusions:

• Dose addition is a valuable predictive screening tool for ecological risk assessment of PFAS mixtures.
• Understanding mixture toxicity is crucial for accurate real-world environmental risk characterization.
• Further refinement is needed for site-specific risk differentiation.