U.S. Geological Survey, 2280 Woodale Drive, Mounds View, MN, 55112, United States.
U.S. National Park Service, Great Lakes Inventory & Monitoring Network, 2800 Lake Shore Drive East, Ashland, WI, 54806, United States.
Environ Pollut. 2019 Jan;244:861-870. doi: 10.1016/j.envpol.2018.10.093. Epub 2018 Oct 24.
Several organic contaminants (OCs) have been detected in bald eagle (Haliaeetus leucocephalus) nestling (eaglet) plasma in the upper Midwestern United States. Despite frequent and relatively high concentrations of OCs in eaglets, little is understood about potential biological effects associated with exposure. We screened an existing database of OC concentrations in eaglet plasma collected from the Midwestern United States against bioactivity information from the ToxCast database. ToxCast bioactivity information consists of concentrations expected to elicit responses across a range of biological space (e.g. cellular, developmental, etc.) obtained from a series of high throughput assays. We calculated exposure-activity ratios (EAR) by calculating the ratio of plasma concentrations to concentrations available in ToxCast. Bioactivity data were not available for all detected OCs. Therefore, our analysis provides estimates of potential bioactivity for 19 of the detected OCs in eaglet plasma. Perfluorooctanesulfonic acid (PFOS) EAR values were consistently the highest among all study areas. Maximum EAR values were ≥1 for PFOS, perfluorononanoic acid, and bisphenol A in 99.7, 0.53 and 0.26% of samples, indicating that some plasma concentrations were greater than what may be expected to elicit biological responses. About 125 gene targets, indicative of specific biological pathways, were identified as potentially being affected. Inhibition of several CYP genes, involved in xenobiotic metabolism, were most consistently identified. Other identified biological responses have potential implications for motor coordination, cardiac functions, behavior, and blood circulation. However, it is unclear what these results mean for bald eagles, given that ToxCast data are generated using mammalian-based endpoints. Despite uncertainties and limitations, this method of screening environmental data can be useful for informing future monitoring or research focused on understanding the occurrence and effects of OCs in bald eagles and other similarly-positioned trophic species.
在美国中西部的白头鹰（Haliaeetus leucocephalus）雏鸟（雏鹰）血浆中已经检测到几种有机污染物（OCs）。尽管雏鹰体内 OCs 的浓度经常很高，但对其暴露相关的潜在生物学效应却知之甚少。我们从美国中西部收集的雏鹰血浆 OC 浓度的现有数据库中筛选了与 ToxCast 数据库中的生物活性信息相对应的内容。ToxCast 生物活性信息由一系列高通量测定中预期引起一系列生物空间（如细胞、发育等）反应的浓度组成。我们通过将血浆浓度除以 ToxCast 中可用的浓度来计算暴露-活性比（EAR）。并非所有检测到的 OCs 都有生物活性数据。因此，我们的分析为雏鹰血浆中检测到的 19 种 OCs 的潜在生物活性提供了估计值。全氟辛烷磺酸（PFOS）EAR 值在所有研究区域中始终最高。在 99.7%、0.53%和 0.26%的样本中，PFOS、全氟壬酸和双酚 A 的最大 EAR 值≥1，表明一些血浆浓度大于可能引起生物学反应的浓度。约有 125 个基因靶点被确定为可能受到影响，这些靶点表明了特定的生物学途径。几种参与外来生物代谢的 CYP 基因的抑制作用最为一致地被识别出来。其他鉴定出的生物学反应可能对运动协调、心脏功能、行为和血液循环产生影响。然而，鉴于 ToxCast 数据是使用基于哺乳动物的终点生成的，这些结果对白头鹰意味着什么还不清楚。尽管存在不确定性和局限性，但这种筛选环境数据的方法对于为未来的监测或研究提供信息可能很有用，这些研究旨在了解白头鹰和其他类似位置的营养物种中 OCs 的发生和影响。
