Marteinson Sarah C, Eulaers Igor, Jaspers Veerle L B, Covaci Adrian, Eens Marcel, Letcher Robert J, Fernie Kim J
Ecotoxicology and Wildlife Health Division, Wildlife and Landscape Science Directorate, Environment and Climate Change Canada, Burlington, Ontario, Canada.
Department of Bioscience, Aarhus University, Frederiksborgvej 399, PO Box 358, 4000 Roskilde, Denmark.
Environ Pollut. 2017 Jan;220(Pt A):441-451. doi: 10.1016/j.envpol.2016.09.086. Epub 2016 Oct 1.
Feathers are useful for monitoring contaminants in wild birds and are increasingly used to determine persistent organic pollutants. However, few studies have been conducted on birds with known exposure levels. We aimed to determine how well nestling feather concentrations reflect in ovo exposure to hexabromocyclododecane (α-, β- and γ-HBCDD), and to determine if feather concentrations are related to physiological biomarkers. Captive kestrels (n = 11) were exposed in ovo to maternally transferred HBCDD-isomers at concentrations of 127, 12 and 2 ng/g wet weight of α-, β- and γ-HBCDD (measured in sibling eggs), respectively, and compared to controls (n = 6). Nestling growth was monitored at 5 d intervals and circulating thyroid hormone concentrations assessed at d 20. Tail feathers were collected prior to the first molt and analyzed for HBCDD isomers. The mean ΣHBCDD concentration in feathers was 2405 pg/g dry weight (in exposed birds) and α-, β- and γ-HBCDD made up 32%, 13%, and 55%, respectively of the ΣHBCDD concentrations. This isomer distribution deviated from the typical dominance of α-HBCDD reported in vertebrate samples. Exposed chicks had significantly higher feather concentrations of β- and γ-HBCDD compared with controls (p = 0.007 and p = 0.001 respectively), while α-HBCDD concentrations did not differ between the two groups. Feather concentrations of α-HBCDD were best explained by egg concentrations of β- or γ-HBCDD concentrations (w = 0.50, 0.30 respectively), while feather concentrations of β- and γ-HBCDD were influenced by growth parameters (rectrix length: w = 0.61; tibiotarsus length: w = 0.28). These results suggest that feather α-HBCDD concentrations may reflect internal body burdens, whereas β- and γ-HBCDD may be subject to selective uptake. The α-HBCDD concentrations in the feathers were negatively associated with the ratio of plasma free triiodothyronine to free thyroxine (T:T; p = 0.020), demonstrating for the first time that feather concentrations may be used to model the effect of body burdens on physiological endpoints.
羽毛有助于监测野生鸟类体内的污染物，并且越来越多地用于确定持久性有机污染物。然而，针对已知暴露水平鸟类的研究却很少。我们旨在确定雏鸟羽毛中的污染物浓度能多好地反映其胚胎期对六溴环十二烷（α-、β-和γ-六溴环十二烷）的暴露情况，并确定羽毛中的污染物浓度是否与生理生物标志物相关。将圈养的红隼（n = 11）胚胎期分别暴露于母体转移的浓度为127、12和2纳克/克湿重（在同胞卵中测得）的α-、β-和γ-六溴环十二烷异构体中，并与对照组（n = 6）进行比较。每隔5天监测雏鸟的生长情况，并在第20天评估循环甲状腺激素浓度。在首次换羽前收集尾羽，分析其中六溴环十二烷异构体的含量。羽毛中六溴环十二烷的平均总浓度为2405皮克/克干重（暴露组雏鸟），α-、β-和γ-六溴环十二烷分别占六溴环十二烷总浓度的32%、13%和55%。这种异构体分布与脊椎动物样本中报道的典型的α-六溴环十二烷占主导地位的情况不同。与对照组相比，暴露组雏鸟羽毛中β-和γ-六溴环十二烷的浓度显著更高（分别为p = 0.007和p = 0.001），而两组间α-六溴环十二烷的浓度没有差异。α-六溴环十二烷的羽毛浓度最好由β-或γ-六溴环十二烷的卵浓度来解释（权重分别为0.50、0.30），而β-和γ-六溴环十二烷的羽毛浓度受生长参数影响（尾羽长度：权重 = 0.61；胫跗骨长度：权重 = 0.28）。这些结果表明，羽毛中α-六溴环十二烷的浓度可能反映体内负担，而β-和γ-六溴环十二烷可能存在选择性摄取。羽毛中α-六溴环十二烷的浓度与血浆游离三碘甲状腺原氨酸与游离甲状腺素的比值（T:T；p = 0.020）呈负相关，首次证明羽毛浓度可用于模拟体内负担对生理指标的影响。
