Department of Biological Sciences, Eastern Illinois University, 600 Lincoln Ave, Charleston, IL, 61920, USA,
Environ Monit Assess. 2014 Apr;186(4):2067-79. doi: 10.1007/s10661-013-3518-3. Epub 2014 Jan 4.
The U.S. Department of Energy's (USDOE) Savannah River Site (SRS) is a former nuclear weapon material production and current research facility adjacent to the Savannah River in South Carolina, USA. The purpose of this study was to determine the background radiocesium ((137)Cs) body burden (e.g., from global fallout) for white-tailed deer (Odocoileus virginianus) inhabiting the SRS. To differentiate what the background burden is for the SRS versus (137)Cs obtained from SRS nuclear activities, data were analyzed spatially, temporally and compared to other off-site hunting areas near the SRS. The specific objectives of this study were: to compare SRS and offsite deer herds based on time and space; to interpret comparisons based on how data were collected as well as the effect of environmental and anthropogenic influences; to determine what the ecological half-life/decay rate is for (137)Cs in the SRS deer herd; and to give a recommendation to what should be considered the background (137)Cs level in the SRS deer herd. Based on the available information and analyses, it is recommended that the determination of what is considered background for the SRS deer herd be derived from data collected from the SRS deer herd itself and not offsite collections for a variety of reasons. Offsite data show extreme variability most likely due to environmental factors such as soil type and land-use patterns (e.g., forest, agriculture, residential activities). This can be seen from results where samples from offsite military bases (Fort Jackson and Fort Stewart) without anthropogenic (137)Cs sources were much higher than both the SRS and a nearby (Sandhills) study site. Moreover, deer from private hunting grounds have the potential to be baited with corn, thus artificially lowering their (137)Cs body burdens compared to other free-ranging deer. Additionally, sample size for offsite collections were not robust enough to calculate a temporal decay curve with an upper confidence level to determine if the herds are following predicted radioactive decay rates like the SRS or if the variability is due to those points described above. Using mean yearly values, the ecological half-life for (137)Cs body burdens for SRS white-tailed deer was determined to be 28.79 years--very close to the 30.2 years physical half-life.
美国能源部的萨凡纳河场址（SRS）是美国南卡罗来纳州萨凡纳河附近的一个前核武器材料生产厂和当前的研究设施。本研究的目的是确定栖息在 SRS 的白尾鹿（Odocoileus virginianus）的背景放射性铯（137Cs）（例如，来自全球沉降物）的体负荷。为了区分 SRS 的背景负担与 SRS 核活动获得的 137Cs，我们对空间、时间数据进行了分析，并与 SRS 附近的其他场外狩猎区进行了比较。本研究的具体目标是：根据时间和空间比较 SRS 和场外鹿群；根据数据收集方式以及环境和人为影响的作用来解释比较结果；确定 SRS 鹿群中 137Cs 的生态半衰期/衰减率；并对 SRS 鹿群中 137Cs 的背景水平提出建议。根据现有资料和分析，建议根据 SRS 鹿群本身的数据而不是场外数据来确定 SRS 鹿群的背景水平，原因有很多。场外数据显示出极端的可变性，这很可能是由于土壤类型和土地利用模式等环境因素（如森林、农业、住宅活动）造成的。从结果可以看出，没有人为 137Cs 源的场外军事基地（杰克逊堡和斯图尔特堡）的样本比 SRS 和附近（沙丘）研究地点的样本高得多。此外，来自私人狩猎地的鹿可能会被玉米诱饵，因此与其他自由放养的鹿相比，它们的 137Cs 体负荷会人为降低。此外，场外采集的样本量不够大，无法计算出具有较高置信水平的时间衰减曲线，以确定鹿群是否遵循 SRS 预测的放射性衰减率，还是由于上述因素导致的可变性。使用年平均值，确定 SRS 白尾鹿 137Cs 体负荷的生态半衰期为 28.79 年，非常接近 30.2 年的物理半衰期。
