Date
8-4-2022 12:00 AM
Poster Abstract
Per- and polyfluoroalkyl substances (PFAS) are a class of ubiquitous environmental contaminants commonly found in estuarine environments. Estuaries are dynamic systems with regular, dramatic fluctuations in abiotic factors such as salinity, dissolved oxygen, and temperature. Despite this, how abiotic factors mediate PFAS toxicity remains unexplored. We tested the hypothesis that salinity mediates toxicity of perfluorooctane sulfonate (PFOS) in embryonic and larval sheepshead minnows (Cyprinodon variegatus; a model estuarine fish). In two factorial experiments, we exposed embryos through hatching and larvae to PFOS for 96 hours at 1, 10, 100, 1,000, and 10,000 parts per billion (ppb) across two salinity levels (10 and 30 parts per thousand (ppt)). In the embryonic exposure, we measured survival, size, and rate of development and in the larval exposure, measured survival and size. Although we found no effects on embryo survival, we observed increased time to hatch at 10,000 ppb PFOS, but no salinity by PFOS interactions. In contrast, larval survival was significantly reduced by PFOS, and PFOS was 3 times more toxic at 30 ppt relative to the 10 ppt salinity (LC50, 30 ppt = 1,108 ppb , LC50, 10 ppt = 3,106 ppb). Measured PFOS concentrations in water suggest that salinity may have influenced bioavailability of PFAS, which could explain the observed PFOS by salinity interaction on the larval LC50. Our results warrant more work aimed at assessing if/how PFAS toxicity is mediated by salinity and/or other factors that fluctuate under field conditions.
Is Toxicity of Perflurooctanesulfonic Acid Mediated by Salinity in Estuarine Larvae and Embryos?
Per- and polyfluoroalkyl substances (PFAS) are a class of ubiquitous environmental contaminants commonly found in estuarine environments. Estuaries are dynamic systems with regular, dramatic fluctuations in abiotic factors such as salinity, dissolved oxygen, and temperature. Despite this, how abiotic factors mediate PFAS toxicity remains unexplored. We tested the hypothesis that salinity mediates toxicity of perfluorooctane sulfonate (PFOS) in embryonic and larval sheepshead minnows (Cyprinodon variegatus; a model estuarine fish). In two factorial experiments, we exposed embryos through hatching and larvae to PFOS for 96 hours at 1, 10, 100, 1,000, and 10,000 parts per billion (ppb) across two salinity levels (10 and 30 parts per thousand (ppt)). In the embryonic exposure, we measured survival, size, and rate of development and in the larval exposure, measured survival and size. Although we found no effects on embryo survival, we observed increased time to hatch at 10,000 ppb PFOS, but no salinity by PFOS interactions. In contrast, larval survival was significantly reduced by PFOS, and PFOS was 3 times more toxic at 30 ppt relative to the 10 ppt salinity (LC50, 30 ppt = 1,108 ppb , LC50, 10 ppt = 3,106 ppb). Measured PFOS concentrations in water suggest that salinity may have influenced bioavailability of PFAS, which could explain the observed PFOS by salinity interaction on the larval LC50. Our results warrant more work aimed at assessing if/how PFAS toxicity is mediated by salinity and/or other factors that fluctuate under field conditions.
Comments
2022 FNR Poster Competition, Graduate Research, Honorable Mention [tie]