Paller Michael H, Timothy Jannik G, Wike Lynn D
Savannah River National Laboratory, Westinghouse Savannah River Company, Savannah River Site, Aiken, SC 29808, USA.
J Environ Radioact. 2006;90(3):224-35. doi: 10.1016/j.jenvrad.2006.07.004. Epub 2006 Sep 8.
(137)Cs concentration ratios were computed for small mammals collected from the dried sediments of a partially drained, contaminated reservoir. Soil (137)Cs activity concentrations were heterogeneous on small and large spatial scales and had a geometric mean of 253 (range 23-2110) Bq/kg dry weight. Mean (137)Cs activity concentrations in composite cotton rat Sigmodon hispidus and cotton mouse Peromyscus gossypinus samples averaged 2480 (range 556-6670) and 471 (range 96-1000) Bq/kg whole body dry weight, respectively. About 50% of the variance in cotton rat tissue (137)Cs activity was explained by variation in soil (137)Cs activity. Soil-to-animal dry weight concentration ratios averaged 6.0 for cotton rats and 1.2 for cotton mice and were generally similar to (137)Cs concentration ratios for herbivorous, homeothermic animals from other contaminated ecosystems. In the RESRAD-BIOTA dose model, the default wet-weight concentration ratio for (137)Cs in terrestrial animals is 110 resulting in an estimate of internal and external radiation doses to terrestrial biota that is 44 times more than the dose calculated with the actual measured wet-weight concentration ratio for cotton rats (1.6). These results show that site-specific concentration ratios can significantly affect the estimation of dose.
计算了从部分排水的受污染水库干涸沉积物中采集的小型哺乳动物体内的铯 - 137浓度比。土壤中铯 - 137的活度浓度在小尺度和大尺度空间上均不均匀，干重的几何平均值为253（范围为23 - 2110）贝克勒尔/千克。棉鼠（Sigmodon hispidus）和棉鼠（Peromyscus gossypinus）混合样本中铯 - 137的平均活度浓度分别为2480（范围为556 - 6670）和471（范围为96 - 1000）贝克勒尔/千克全身干重。棉鼠组织中铯 - 137活度的约50％差异可由土壤中铯 - 137活度的变化来解释。棉鼠的土壤与动物干重浓度比平均为6.0，棉鼠为1.2，这通常与来自其他受污染生态系统的草食性恒温动物的铯 - 137浓度比相似。在RESRAD - BIOTA剂量模型中，陆地动物中铯 - 137的默认湿重浓度比为110，这导致对陆地生物群的内部和外部辐射剂量的估计比用棉鼠实际测量的湿重浓度比（1.6）计算出的剂量高出44倍。这些结果表明，特定地点的浓度比会显著影响剂量估计。
