University of Georgia, Warnell School of Forestry and Natural Resources, 180 E. Green St., Athens, GA 30602, USA; University of Georgia, Savannah River Ecology Laboratory, P.O. Drawer E, Aiken, SC 29803, USA.
University of Georgia, Warnell School of Forestry and Natural Resources, 180 E. Green St., Athens, GA 30602, USA.
Sci Total Environ. 2017 Aug 15;592:25-32. doi: 10.1016/j.scitotenv.2017.03.055. Epub 2017 Mar 12.
Various anthropogenic activities have resulted in concentration of heavy metals and contamination of surrounding environments. Historically, heavy metal contamination at the Savannah River Site (SRS) in South Carolina has resulted from accidental releases of stored waste generated from nuclear weapon production in the early 1950s. Songbirds inhabiting and using resources from these areas have the potential to bioaccumulate metals but there is limited information on metal concentration levels in areas suspected of contamination as well as uncontaminated sites. Nonlethal tissues samples from avian blood and feathers provide a reliable approach for determining the bioavailability of these pollutants (As, Cd, Cr, Cu, Hg, Ni, Pb, Se, and Zn). The objectives of this study were to survey terrestrial heavy metal contamination at the SRS on potentially bioavailable contaminated (PBC) sites through blood and feather samples from resident Northern Cardinals (Cardinalis cardinalis) and migratory Great Crested Flycatchers (Myiarchus crinitus) and quantify sex-specific concentrations within species. Samples were collected in April to June of 2016. Cardinals had lower blood concentrations of Hg (β=-0.17, 85% CL=-0.26, -0.09) and Se (β=-0.33, 85% CL=-0.50, -0.16) than flycatchers. Cr feather concentrations were less in cardinals (β=-1.46, 85% CL=-2.44, -0.49) and all feathers of both species from reference locations had significantly less Zn (β=-67.92, 85% CL=-128.71, -7.14). Results indicate flycatchers were exposed to differing heavy metal levels during feather formation on their wintering grounds as compared to their recent exposure (through bloods samples) on their breeding grounds. Sex of individuals did not have a significant impact on bioaccumulation in either species. Overall, metal concentration levels in both species indicate minimal risk for acute toxicity; however, there is limited research on wild passerine populations with similar concentration levels. Therefore, further research on reproductive success of these birds should be explored.
各种人为活动导致重金属浓度升高，周围环境受到污染。历史上，南卡罗来纳州萨凡纳河场址（SRS）的重金属污染是由于 20 世纪 50 年代早期核武器生产过程中储存的废物意外释放造成的。栖息和利用这些地区资源的鸣禽有可能积累金属，但关于疑似污染地区以及未污染地区的金属浓度水平的信息有限。来自鸟类血液和羽毛的非致死组织样本为确定这些污染物（砷、镉、铬、铜、汞、镍、铅、硒和锌）的生物利用度提供了可靠的方法。本研究的目的是通过来自本地北方红雀（Cardinalis cardinalis）和迁徙的大冠蝇霸鹟（Myiarchus crinitus）的血液和羽毛样本，调查 SRS 上潜在生物可用污染（PBC）地点的陆地重金属污染，并量化种内的性别特异性浓度。样本于 2016 年 4 月至 6 月采集。与蝇霸鹟相比，红雀的血液中汞（β=-0.17，85%置信区间=-0.26，-0.09）和硒（β=-0.33，85%置信区间=-0.50，-0.16）浓度较低。红雀的羽毛铬浓度较低（β=-1.46，85%置信区间=-2.44，-0.49），而且两种物种的所有参考地点的羽毛锌浓度均显著较低（β=-67.92，85%置信区间=-128.71，-7.14）。结果表明，与繁殖地的近期暴露（通过血液样本）相比，蝇霸鹟在冬季筑巢地形成羽毛时，暴露于不同水平的重金属。个体的性别对两种物种的生物积累都没有显著影响。总体而言，两种物种的金属浓度水平表明急性毒性的风险极小；然而，关于具有类似浓度水平的野生雀形目鸟类种群的研究有限。因此，应该进一步研究这些鸟类的繁殖成功率。
