Punshon T, Gaines K F, Jenkins R A
University of Georgia, Savannah River Ecology Labarotory, Drawer E, Aiken, South Carolina 29802, USA.
Arch Environ Contam Toxicol. 2003 Jan;44(1):30-5. doi: 10.1007/s00244-002-1213-4.
Elemental composition of soil, herbaceous and woody plant species, and the muscle and liver tissue of two common small mammal species were determined in a wetland ecosystem contaminated with Ni and U from nuclear target processing activities at the Savannah River Site, Aiken, SC. Species studied were black willow ( Salix nigra L.), rushes ( Juncus effusus L.), marsh rice rat ( Oryzomys palustris), and cotton rat ( Sigmodon hispidus). Two mature trees were sampled around the perimeter of the former de facto settling basin, and transect lines sampling rushes and trapping small mammals were laid across the wetland area, close to a wooden spillway that previously enclosed the pond. Ni and U concentrations were elevated to contaminant levels; with a total concentration of 1,065 (+/- 54) mg kg(-1) U and 526.7 (+/-18.3) mg kg(-1) Ni within the soil. Transfer of contaminants into woody and herbaceous plant tissues was higher for Ni than for U, which appeared to remain bound to the outside of root tissues, with very little (0.03 +/- 0.001 mg kg(-1)) U detectable within the leaf tissues. This indicated a lower bioavailability of U than the cocontaminant Ni. Trees sampled from the drier margins of the pond area contained more Ni within their leaf tissues than the rushes sampled from the wetter floodplain area, with leaf tissues concentrations of Ni of approximately 75.5 (+/- 3.6) mg kg(-1) Ni. Ni concentrations were also elevated in small mammal tissues. Transfer factors of contaminants indicated that U bioavailability is negligable in this wetland ecosystem.
在美国南卡罗来纳州艾肯市萨凡纳河工厂，对一个因核靶处理活动而受到镍和铀污染的湿地生态系统中的土壤、草本和木本植物物种，以及两种常见小型哺乳动物的肌肉和肝脏组织进行了元素组成测定。所研究的物种有黑柳（Salix nigra L.）、灯心草（Juncus effusus L.）、稻水鼠（Oryzomys palustris）和棉鼠（Sigmodon hispidus）。在先前实际沉降池周边采集了两棵成年树木的样本，并在湿地区域设置了横跨灯心草的样线以及用于诱捕小型哺乳动物的陷阱，样线靠近先前围绕池塘的木制溢洪道。镍和铀的浓度升高至污染水平；土壤中铀的总浓度为1,065（±54）mg kg⁻¹，镍的总浓度为526.7（±18.3）mg kg⁻¹。镍向木本和草本植物组织中的污染物转移高于铀，铀似乎仍与根组织外部结合，在叶片组织中仅能检测到极少的铀（0.03±0.001 mg kg⁻¹）。这表明铀的生物有效性低于共污染物镍。从池塘较干燥边缘采集的树木叶片组织中的镍含量高于从较湿润河漫滩区域采集的灯心草，叶片组织中的镍浓度约为75.5（±3.6）mg kg⁻¹镍。小型哺乳动物组织中的镍浓度也有所升高。污染物的转移因子表明，在这个湿地生态系统中铀的生物有效性可忽略不计。
