Skip to main content
U.S. flag

An official website of the United States government

Mixture effects of per- and polyfluoroalkyl substances on embryonic and larval Sheepshead Minnows (Cyprinodon variegatus)

January 20, 2024
Per- and polyfluoroalkyl substances (PFAS) are ubiquitous and persistent environmental contaminants originating from many everyday products. Perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) are two PFAS that are commonly found at high concentrations in aquatic environments. Both chemicals have previously been shown to be toxic to fish, as well as having complex and largely uncharacterized mixture effects. However, limited information is available on marine and estuarine species. In this study, embryonic and larval sheepshead minnows (Cyprinodon variegatus) were exposed to several PFAS mixtures to assess lethal and sublethal effects. PFOS alone was acutely toxic to larvae, with a 96 h LC50 of 1.97 mg/L (1.64–2.16). PFOS + PFOA resulted in a larval LC50 of 3.10 (2.62–3.79) mg/L, suggesting an antagonistic effect. These observations were supported by significant reductions in malondialdehyde (105% ± 3.25) and increases in reduced glutathione concentrations (43.8% ± 1.78) in PFOS + PFOA exposures compared to PFOS-only treatments, indicating reduced oxidative stress. While PFOA reduced PFOS-induced mortality (97.0% ± 3.03), perfluorohexanoic acid (PFHxA) and perfluorobutanoic acid (PFBA) did not. PFOS alone did not affect expression of peroxisome proliferator-activated receptor alpha (pparα) but significantly upregulated apolipoprotein A4 (apoa4) (112.4% ± 17.8), a downstream product of pparα, while none of the other individually tested PFAS affected apoa4 expression. These findings suggest that there are antagonistic interactions between PFOA and PFOS that may reduce mixture toxicity in larval sheepshead minnows through reduced oxidative stress. Elucidating mechanisms of toxicity and interactions between PFAS will aid environmental regulation and management of these ubiquitous pollutants.
Publication Year 2024
Title Mixture effects of per- and polyfluoroalkyl substances on embryonic and larval Sheepshead Minnows (Cyprinodon variegatus)
DOI 10.3390/toxics12010091
Authors Philip Tanabe, Peter B. Key, Katy W. Chung, Emily C. Pisarski, Jessica L. Reiner, Rodowa. Alix E., Jason Tyler Magnuson, Marie E. DeLorenzo
Publication Type Article
Publication Subtype Journal Article
Series Title Toxics
Index ID 70251129
Record Source USGS Publications Warehouse
USGS Organization Columbia Environmental Research Center