To further characterize avian toxicity to environmental levels of select per‐ and poly‐fluoroalkyl substances (PFAS), we established species‐ and tissue‐specific PFAS chronic toxicity values (CTVs) associated with a lowest‐observable–adverse effect level (LOAEL) threshold previously established for northern bobwhite quail (Colinus virginianus) chronically orally exposed via drinking water to either perfluorooctane sulfonate (PFOS) or a simple PFAS mixture. Aided by advances in analytical techniques, the novel avian oral PFAS CTVs reported in the present study are lower than the previously reported toxicity reference values (TRVs) estimated for birds chronically exposed via feed. Thus, current avian PFOS TRVs may not be fully protective of wild avian populations at PFAS‐impacted sites. Also, likely due to differences in bioavailability, bioaccessibility, and toxicokinetics among individual PFAS between oral exposure types, we found higher bioaccumulation factors in all assessed tissues from birds exposed via water versus feed. Thus, we propose that future characterization of chemical toxicity due to ingestion exposure initially include a full examination of all probable sources of oral exposure for the most accurate derivation of TRVs and a more complete picture of ecological risk. The avian PFAS LOAEL CTVs established in the present study can be modified with the use of uncertainty factors to derive site‐specific avian TRVs for ecological risk assessment at PFAS‐impacted sites. From differences observed in the behavior of PFOS when administered as either a single chemical or part of a binary mixture with perfluorohexane sulfonate (PFHxS), we verified that PFOS was absorbed and distributed differently when coadministered with PFHxS and that PFOS likely interacted with PFHxS differently among tissues, helping to explain the differences observed in avian toxicity between exposures. Environ Toxicol Chem 2021;40:899–909. © 2020 SETAC

中文翻译：

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全氟辛烷磺酸 (PFOS) 和全氟辛烷磺酸和全氟己烷磺酸的二元混合物的物种和组织特异性禽类慢性毒性值

为了进一步表征特定全氟和多氟烷基物质 (PFAS) 对环境水平的禽类毒性，我们建立了与最低可观察到的不良反应水平 (LOAEL) 阈值相关的物种和组织特异性 PFAS 慢性毒性值 (CTV)以前为北白鹌鹑（Colinus virginianus ）建立) 通过饮用水长期口服暴露于全氟辛烷磺酸 (PFOS) 或简单的 PFAS 混合物。借助分析技术的进步，本研究中报告的新型禽类口服 PFAS CTV 低于先前报告的对通过饲料长期暴露的鸟类估计的毒性参考值 (TRV)。因此，目前的鸟类 PFOS TRV 可能无法完全保护受 PFAS 影响地点的野生鸟类种群。此外，可能由于口服暴露类型之间个体 PFAS 的生物利用度、生物可及性和毒代动力学存在差异，我们发现通过水暴露与饲料暴露的鸟类的所有评估组织中的生物蓄积因子更高。因此，我们建议未来对摄入暴露引起的化学毒性的表征最初包括对所有可能的口服暴露来源进行全面检查，以最准确地推导出 TRV 和更完整的生态风险图。本研究中建立的鸟类 PFAS LOAEL CTV 可以通过使用不确定因素进行修改，以获得特定地点的鸟类 TRV，用于 PFAS 影响地点的生态风险评估。从作为单一化学品或与全氟己烷磺酸 (PFHxS) 的二元混合物的一部分给药时观察到的 PFOS 行为差异，我们证实当与 PFHxS 共同给药时，PFOS 的吸收和分布不同，并且 PFOS 与 PFHxS 之间的相互作用可能不同组织，环境毒理学化学2021；40：899-909。© 2020 SETAC