Department of Biological Sciences, Eastern Illinois University, 600 Lincoln Ave, Charleston, IL, 61920, USA.
Environ Monit Assess. 2014 Jan;186(1):481-500. doi: 10.1007/s10661-013-3392-z. Epub 2013 Aug 25.
The Department of Energy's Savannah River Site is a former nuclear weapon material production and current research facility located in South Carolina, USA. Wastewater discharges from a fuel and nuclear reactor target manufacturing facility released depleted and natural U, as well as other metals into the Tims Branch-Steed Pond water system. We investigated the current dynamics of this system for the purposes of environmental monitoring and assessment by examining metal concentrations, bioavailability, and trophic transfer of contaminants in seven ponds. Biofilm, detritus, and Anuran and Anisopteran larvae were collected and analyzed for stable isotopes (δ (15)N, δ (13)C) and contaminants of potential concern (COPC) with a focus on Ni, U, and Hg, to examine metal mobility. Highest levels of Ni and U were found in biofilms U (147 and 332 mg kg(-1) DW, respectively), while highest Hg levels were found in tadpoles (1.1 mg kg(-1) DW). We found intraspecific biomagnification of COPCs as expressed through stable isotope analysis. Biofilms were the best indicators for contamination and Anuran larvae with the digestive tract removed were the best indicators of the specific bioavailability of the focal metals. Monitoring data showed that baseline δ (15)N values differed between ponds, but within a pond, values were stable throughout tadpole Gosner stage, strengthening the case to use this species for monitoring purposes. It is likely that there still is risk to ecosystem integrity as COPC metals are being assimilated into lower trophic organisms and even low levels of this mixture has shown to produce deleterious effects to some wildlife species.
美国能源部萨凡纳河场址是一座前核武器材料生产设施和现研究设施，位于南卡罗来纳州。燃料和核反应堆靶制造设施的废水将贫化铀和天然铀以及其他金属释放到提姆斯支流-斯蒂德池塘水系中。我们通过检查七个池塘中金属浓度、生物可利用性和污染物的营养转移，来研究该系统的当前动态，以便进行环境监测和评估。生物膜、碎屑和蛙类和蜻蜓类幼虫被收集并分析稳定同位素（δ（15）N、δ（13）C）和潜在关注污染物（COPC），重点是 Ni、U 和 Hg，以检查金属的迁移性。在生物膜中发现了最高水平的 Ni 和 U（分别为 147 和 332 mg kg（-1）DW），而在蝌蚪中发现了最高水平的 Hg（1.1 mg kg（-1）DW）。我们通过稳定同位素分析发现了 COPC 的种内生物放大。生物膜是污染的最佳指示物，而去除消化道的蛙类幼虫是焦点金属特定生物可利用性的最佳指示物。监测数据表明，池塘之间的基线 δ（15）N 值存在差异，但在一个池塘内，在蝌蚪戈斯纳阶段整个过程中，值都是稳定的，这增强了使用该物种进行监测的理由。由于 COPC 金属被同化到较低营养级别的生物体中，即使是这种混合物的低水平也对一些野生动物物种产生了有害影响，因此生态系统完整性仍然存在风险。
