Superfund Research Program
December 2024

Exposure to mixtures of PFAS chemicals may pose a greater health risk than exposure to a single PFAS alone, according to SRP-funded researchers at the State University of New York at Buffalo. Results suggest that different PFAS compounds interact in ways that make a mixture more toxic.
The scientists tested four PFAS mixtures that were based on mixtures commonly found in surface water, human blood, and wastewater treatment plants. They predicted the toxicity of each individual PFAS based on how much of the chemical accumulates in cell membranes. To estimate how each mixture may affect health, the researchers used a neurotoxicity assay, which assesses the effects of exposure on the growth of nervous system cells, and a cytotoxicity assay to measure cell damage.
In mixtures, individual PFAS chemicals acted together in an additive manner. Perfluorooctanoic acid (PFOA) was one of the most cytotoxic chemicals in PFAS mixtures despite its low concentrations. PFOA and perfluorooctane sulfonic acid were each responsible for one-quarter of the observed neurotoxic effects, although they only accounted for 10% and 15% of a mixture, respectively.
According to the authors, study results have important implications for risk assessment and suggest that PFAS should be regulated as mixtures.
To learn more, see this Extramural Paper of the Month.