Department of Forestry and Natural Resources, Purdue University, 715 West State Street, West Lafayette, IN, 47907, United States.
Department of Agronomy, Purdue University, 915 West State Street, West Lafayette, IN, 47907, United States.
Ecotoxicol Environ Saf. 2019 Aug 30;178:137-145. doi: 10.1016/j.ecoenv.2019.04.022. Epub 2019 Apr 16.
Poly- and perfluoroalkyl substances (PFAS) are ubiquitous contaminants that can bioaccumulate in aquatic taxa. Amphibians are particularly vulnerable to contaminants and sensitive to endocrine disruptors during their aquatic larval stage. However, few studies have explored PFAS uptake rates in amphibians, which is critical for designing ecotoxicology studies and assessing the potential for bioaccumulation. Uptake rates of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were measured for larval northern leopard frogs (Rana pipiens), American toads (Anaxyrus americanus), and eastern tiger salamanders (Ambystoma tigrinum) during a 240-h exposure to 10 and 1000 μg/L concentrations. We measured body burden and calculated bioconcentration factor (BCF) every 48 h during the experiments. For all species and exposures, body burdens often reached steady state within 48-96 h of exposure. Steady-state body burdens for PFOA and PFOS ranged from 3819 to 16,481 ng/g dry weight (BCF = 0.46-2.5) and 6955-489,958 ng/g dry weight (47-259 BCFs), respectively. Therefore, PFAS steady state occurs rapidly in the larval amphibians we studied and particularly for PFOS. This result reflects a high potential for PFAS trophic transfer because amphibians are often low in trophic position and are important prey for many aquatic and terrestrial species.
多氟和全氟烷基物质（PFAS）是普遍存在的污染物，可在水生生物中生物累积。两栖动物对污染物特别敏感，在其水生幼体阶段对内分泌干扰物也很敏感。然而，很少有研究探索过 PFAS 在两栖动物中的吸收速率，这对于设计生态毒理学研究和评估生物累积的潜力至关重要。在 240 小时暴露于 10 和 1000μg/L 浓度的情况下，测量了幼体北方豹蛙（Rana pipiens）、美洲蟾蜍（Anaxyrus americanus）和东部虎螈（Ambystoma tigrinum）对全氟辛烷磺酸（PFOS）和全氟辛酸（PFOA）的吸收速率。我们每 48 小时测量一次身体负担并计算生物浓缩系数（BCF）在实验过程中。对于所有物种和暴露，在暴露 48-96 小时后，身体负担通常达到稳定状态。PFOA 和 PFOS 的稳定状态身体负担范围为 3819-16481ng/g 干重（BCF=0.46-2.5）和 6955-489958ng/g 干重（47-259 BCFs）。因此，PFAS 在我们研究的幼体两栖动物中很快达到稳定状态，尤其是对于 PFOS。这一结果反映了 PFAS 营养转移的巨大潜力，因为两栖动物的营养位置通常较低，是许多水生和陆地物种的重要猎物。
