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SOT_Developmental toxicity across a suite of structurally diverse per- and polyfluoroalkyl substances (PFAS) in mummichog (Atlantic killifish)
Citation:
Rericha, Y., T. Burke, C. Heyder, K. Wells, H. Schrader, M. Francoeur, L. Mills, N. McNabb, D. Nacci, AND B. Clark. SOT_Developmental toxicity across a suite of structurally diverse per- and polyfluoroalkyl substances (PFAS) in mummichog (Atlantic killifish). Society of Toxicology 63rd Annual Meeting, Salt Lake City, UT, March 10 - 14, 2024.
Impact/Purpose:
Per- and polyfluoroalkyl substances are frequently detected in the environment, highly persistent, and have been associated with adverse health effects in many species, but toxicity data for marine and estuarine fish is severely lacking. This presentation describes the assessment of developmental toxicity of 11 PFAS representing a variety of structural features (i.e., functional head groups and fluorinated chain lengths) in mummichogs (Fundulus heteroclitus), an ecologically important estuarine fish. Embryos were aqueously exposed to PFAS during early developmental stages and evaluated for a suite of developmental endpoints including sublethal morphological and behavioral effects. Findings suggest trends in developmental toxicity in mummichogs associated with structural features, particularly functional head group. Ultimately, this study contributes to characterization of PFAS toxicity, facilitates prioritization of compounds for investigations of the mechanistic pathways underlying toxicity, and informs efforts to understand ecological impacts of PFAS.
Description:
Per- and polyfluoroalkyl substances (PFAS) are increasingly at the forefront of environmental concern. Despite their frequent detection in environmental media, the highly persistent nature of many PFAS, and growing evidence demonstrating adverse health effects in a variety of species, toxicity data for marine and estuarine fish is severely lacking. A better understanding of organismal effects is needed to adequately assess the ecological hazards of PFAS, and ultimately to predict population-level effects. To address this knowledge gap, we conducted systematic developmental toxicity assessments for a structurally diverse suite of priority PFAS in mummichog (Fundulus heteroclitus, Atlantic killifish). The mummichog is a non-migratory, ecologically important estuarine fish that is amenable to the laboratory, enables evaluation of morphological and behavioral endpoints, and has a well-annotated genome that facilitates ‘omics investigations. Mummichog embryos were exposed to 11 PFAS spanning carboxylic acid, sulfonic acid, fluorotelomer sulfonic acid, and sulfonamide functional head group categories, with fluorinated chain lengths ranging from 5-8. Aqueous 6-day exposures (0, 1, 10, or 100 µM) were performed beginning at 1 day post fertilization (dpf), and a suite of developmental endpoints including morphology, heart rate, growth, swim bladder development, and light/dark behavior were assessed between 10-30 dpf. Within the tested concentrations, only the sulfonamide PFAS adversely affected overall survival; 100 µM perfluorohexane sulfonamide (PFHxSA) and perfluorooctane sulfonamide (PFOSA) exposures caused 79% and 100% mortality, respectively, compared to <20% in controls. PFHxSA also induced higher incidence of sublethal effects (i.e., abnormal body and head size, and minor cardiovascular effects). Several PFAS induced abnormal larval behaviors in the light/dark assay. Preliminary analyses suggest that the functional head group of PFAS compounds affects acute overt toxicity in mummichog, but PFAS across structural categories and chain lengths alter behavior. Ongoing analysis of more subtle, sublethal endpoints will further contribute to our understanding of PFAS bioactivity, facilitate prioritization of compounds for multi-omic investigations, and inform population scale predictions of ecological impacts.
