Domestic Dogs and Horses as Sentinels of Per- and Polyfluoroalkyl Substance Exposure and Associated Health Biomarkers in Gray’s Creek North Carolina

Abstract

Central North Carolina (NC) is highly contaminated with per- and polyfluoroalkyl substances (PFAS), in part due to local fluorochemical production. Little is known about the exposure profiles and long-term health impacts for humans and animals that live in nearby communities. In this study, serum PFAS concentrations were determined using liquid chromatography high-resolution mass spectrometry and diagnostic clinical chemistry endpoints were assessed for 31 dogs and 32 horses that reside in Gray’s Creek NC at households with documented PFAS contamination in their drinking water. PFAS were detected in every sample, with 12 of the 20 PFAS detected in ≥50% of samples from each species. The average total PFAS concentrations in horses were lower compared to dogs who had higher concentrations of PFOS (dogs 2.9 ng/mL; horses 1.8 ng/mL), PFHxS (dogs 1.43 ng/mL, horses < LOD), and PFOA (dogs 0.37 ng/mL; horses 0.10 ng/mL). Regression analysis highlighted alkaline phosphatase, glucose, and globulin proteins in dogs and gamma glutamyl transferase in horses as potential biomarkers associated with PFAS exposure. Overall, the results of this study support the utility of companion animal and livestock species as sentinels of PFAS exposure differences inside and outside of the home. As in humans, renal and hepatic health in domestic animals may be sensitive to long-term PFAS exposures.

Quantitative Cross-Species Comparison of Serum Albumin Binding of Per- and Polyfluoroalkyl Substances from Five Structural Classes

“…Overall, HSA and RSA were quite similar in binding affinities for most PFAS, and our findings suggest that guideline toxicity studies in rat models are not likely to be greatly impacted by species differences in albumin binding for the PFAS congeners in our test set. PFAS have also been detected widely in the tissues of livestock species, including cows and pigs, and are excreted in dairy milk (Guruge et al 2008; van Asselt et al 2013; Numata et al 2014; Death et al 2021; Rock et al 2023). As one of the major routes of exposure to PFAS for humans is consumption of contaminated food and water, assessment of PFAS accumulation in livestock species is also needed to evaluate the role of livestock consumption in human PFAS exposure (Sunderland et al 2019; Roth et al 2020).…”

“…Per- and polyfluoroalkyl substances (PFAS) are a class of synthetic chemicals, comprising thousands of structurally diverse compounds with at least one fully fluorinated methyl or methylene group (OECD 2021). Due to their stability, persistence, and widespread use, PFAS are ubiquitously detected in biological and environmental matrices (Cousins et al 2020; Guillette et al 2020; Kotlarz et al 2020; Cousins et al 2022; Guillette et al 2022; Kirkwood et al 2022; Rock et al 2023). Some PFAS are toxic to multiple organ systems, including the hepatic, renal, immune, reproductive and nervous systems (Carlson et al 2022; Radke et al 2022; Crawford et al 2023).…”

Current Review of Increasing Animal Health Threat of Per- and Polyfluoroalkyl Substances (PFAS): Harms, Limitations, and Alternatives to Manage Their Toxicity

“…Another sentinel study also conducted in North Carolina on dogs and horses showed that average concentrations of total PFAS in horses were lower than in dogs. The dogs in the study had higher concentrations of PFOS, PFHxS and PFOA than the horses, and the researchers highlighted alkaline phosphatase, glucose and globulin in dogs and gamma glutamyl transferase in horses as potential biomarkers associated with PFAS exposure [105]. Through the various pathways of PFAS release into the environment, the potential risk affects not only terrestrial organisms, but also and especially aquatic organisms, water being the major environmental vehicle for these substances.…”