Effects of PFOA and 6:2 FTS Across Sex and Life Stages in Xenopus Laevis

<p>Per- and polyfluoroalkyl substances (PFAS) are an emerging, global threat to environmental health due to their persistence in the environment and their toxicity. The effects of perfluorooctanoic acid (PFOA) and 6:2 fluorotelomere sulfonate (FTS), a legacy and next generation PFAS respectively, have not been explored for <em>Xenopus laevis</em>. In addition, whether sexes differ in responses to PFAS exposure is unexplored in amphibians. The aims of this work were to establish toxicity reference values for PFOA and 6:2 FTS for <em>X. laevis </em>and to test whether any observed effects were sex-specific. Larvae were exposed to a range of PFOA (1.2 to 100 ppm) and 6:2 FTS (1.2 to 1200 ppb) from Niewkoop and Faber (NF) stage 51 to 65. Although we observed no effects on survival, snout-vent length, body condition, or developmental rate, a significant increase in body weight was detected for the two highest concentrations of PFOA (mean of 8.74%) and 6:2 FS (21.01%). Effects were not affected by genetic sex, therefore future studies may be able to ignore sex as a confounding variable under these exposure conditions. Our results also support the idea of PFOA and 6:2FTS act as obesogens. More studies are needed to determine the long-term implications of this increase in body mass.</p>