Data for: Chronic PFAS-exposure under environmentally relevant conditions delays development in northern leopard frog (Rana pipiens) larvae

<p>Perfluoroalkyl substances (PFAS) are pervasive in aquatic systems globally and capable of causing detrimental effects on human and wildlife health. However, most studies are conducted under artificial conditions that are not representative of environmental exposures. Environmental exposures are characterized by multiple routes of exposure, low aquatic PFAS levels, and greater environmental variability than laboratory tests. Determining whether these factors influence toxicity is critical for understanding the effects of PFAS on aquatic life, including amphibians. Our goal was to assess the impact of PFAS on an amphibian under semi-realistic conditions. We reared northern leopard frog (<em>Rana pipiens</em>) larvae in outdoor mesocosms containing sediment spiked to low, medium, and high levels (nominally 10, 100, or 1000 ppb dw) of perfluorooctanesulfonic acid (PFOS) or perfluorooctanoic acid (PFOA) for 30 days. Larvae in all PFOS treatments and the medium-PFOA treatment were ~1.5 Gosner stages less developed than control animals after 30 days. Notably, these developmental delays were observed at PFOS concentrations in the water as low as 0.06 ppb, which is considerably lower than levels associated with developmental effects in laboratory studies. Our results suggest that deriving toxicity values from laboratory studies examining aquatic exposure only may underestimate the effects of environmental PFAS exposure. </p>