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High-Throughput Behavioral Effects of Multiple PFAS Chemicals in Larval Pimephales Promelas
Citation:
Hoang, J., M. Le, B. Blackwell, K. Bush, M. Ellman, K. Flynn, M. Hazemi, E. Stacy, AND Dan Villeneuve. High-Throughput Behavioral Effects of Multiple PFAS Chemicals in Larval Pimephales Promelas. SETAC North America, Pittsburgh, PA, November 13 - 17, 2022. https://doi.org/10.23645/epacomptox.21561504
Impact/Purpose:
Poster presented to the Society of Environmental Toxicology and Chemistry (SETAC) annual meeting November 2022. Per and polyfluorinated alkyl substances (PFAS) are a class of chemicals of high concern with respect to potential effects on human health and/or ecosystems. While toxicity of a few PFAS has been well studied, data are lacking for many chemicals in this overall class. Thus, there is an urgent need to expand the range of chemicals to the point where structural features associated with increased toxicity or other unfavorable properties can be identified. The present study employs a high throughput behavior assay with larval fathead minnows to characterize potential ecological hazards associated with 22 PFAS of varying chain length and functional groups. These data, along with other high throughput data being collected may help to reveal predictive relationships that can aid EPA’s program offices and regions in grouping PFAS chemicals and identifying relative concern for ecological hazard.
Description:
Due to their prevalence in the environment and concerns regarding potential toxicity, there has been a surge in public support to further research per- and polyfluoroalkyl substances (PFAS) and better understand their fate, toxicokinetic properties, and potential adverse effects. The present study used a 24-hour high throughput assay to evaluate the effects of 22 PFAS on locomotor responses in larval Pimephales promelas. Five-day old Pimephales promelas were exposed to individual PFAS at 0.03, 0.1, 0.32, 1, 3.17, 10, 31.67, or 100 µM for 24 hours in deep well, 96 well microplates. Additionally, exposures with potential positive control chemicals, caffeine and ethanol, were performed. Following exposure, plates were placed in a DanioVision observation chamber; behaviors, including percent activity and distance traveled, were recorded using high content video over a 5-minute light on-off protocol utilizing EthoVision XT 15 detection software. The data were subsequently exported and processed through a custom data analysis pipeline in R to measure relevant endpoints, such as average percent activity when the light was on. While the majority of PFAS chemicals tested showed little to no effect on behavioral endpoints, potassium perfluorooctanesulfonate and 3H-Perfluoro-2,2,4,4-tetrahydroxypentane altered behavioral responses in a dose-dependent manner. Potassium perfluorooctanesulfonate significantly increased photomotor responses beginning at 10 µM, whereas 3H-Perfluoro-2,2,4,4-tetrahydroxypentane significantly decreased responses at 31.67 µM. In relation to survival, perfluorooctanesulfonate had no mortality within any of the tested concentrations, while the 100 µM 3H-Perfluoro-2,2,4,4-tetrahydroxypentane concentration elicited 13% mortality across 3 replicate plates. Caffeine showed promising results as a possible positive control, whereas ethanol will require further testing. Overall, this assay demonstrated that while most PFAS studied had little effect on larval Pimephales promelas behavior, certain chemicals did produce a response that could not be captured by the mortality endpoint alone. Results of these behavioral assays will be further compared with both mortality and transcriptomics-based points of departure to provide novel information on the potency of the tested PFAS and potential insights into structural features that may lead to toxicity in fish. The contents of this abstract neither constitute, nor necessarily reflect, official US EPA policy.
URLs/Downloads:
DOI: High-Throughput Behavioral Effects of Multiple PFAS Chemicals in Larval Pimephales Promelas
2022_SETAC_POSTER_HOANG_JOHNV5B.PDF (PDF, NA pp, 958.343 KB, about PDF)