Abstract：
Per- and polyfluoroalkyl substances (PFAS) occur in the environment as mixtures, yet mixture toxicity remains poorly understood. Aqueous film-forming foams (AFFFs) are a common source of PFAS. Our objective was to examine chronic effects of a complex PFAS mixture on amphibian growth and development. We tested toxicity of a five-chemical PFAS mixture summing to 10 μg/L and that accounts for >90% of the PFAS in AFFF-affected surface waters: perfluorooctane sulfonate (PFOS, 40%), perfluorohexane sulfonic acid (PFHxS, 30%), perflurooctanoic acid (PFOA, 12.5%), perfluorohexanoic acid (PFHxA, 12.5%), and perfluoropentanoic acid (PFPeA, 5%). We also included treatments to determine whether PFOS drove mixture toxicity and whether PFOS and mixture components act additively. We exposed Northern leopard frog (Rana pipiens) larvae through metamorphosis (∼130 d) in outdoor mesocosms. After 21 days of exposure, the larval body condition fell ∼5% relative to controls in the 4 μg/L PFOS treatment and mixtures lacking PFOS. At metamorphosis, the full 5-component 10 μg/L PFAS mixture reduced mass by 16% relative to controls. We did not observe effects on development. Our results indicate that toxicity of PFOS and other PFAS mixtures typical of AFFF sites act additively and that PFOS is not more inherently toxic than other mixture components.
摘要：
全氟烷基和多氟烷基物质（PFAS）在环境中以混合物的形式出现，然而，混合物的毒性仍然知之甚少。水性成膜泡沫(AFFF)是PFAS的常见来源。我们的目的是研究复杂的PFAS混合物对两栖动物生长和发育的慢性影响。我们测试了五种化学PFAS混合物的毒性，总计为10μg/L，在受AFFF影响的地表水中占PFAS的90％以上：全氟辛烷磺酸（PFOS，40%)，全氟己烷磺酸(PFHxS，30%),全氟辛酸(PFOA，12.5%），全氟己酸(PFHxA，12.5%），和全氟戊酸(PFPeA，5%)。我们还包括治疗方法，以确定全氟辛烷磺酸是否驱动混合物毒性，以及全氟辛烷磺酸和混合物成分是否具有添加剂作用。我们在户外中观中通过变态（〜130d）暴露了北豹蛙（Ranapipiens）幼虫。暴露21天后，在4μg/L全氟辛烷磺酸处理和缺乏全氟辛烷磺酸的混合物中，幼虫的身体状况相对于对照组下降了约5%。在变态时，与对照组相比，完整的5组分10μg/LPFAS混合物的质量降低了16％。我们没有观察到对发育的影响。我们的结果表明，PFOS和AFFF位点典型的其他PFAS混合物的毒性具有附加作用，并且PFOS的固有毒性并不比其他混合物成分更大。
