Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 12
Book Description
Comparative Study of 137Cs Transfer from Soil to Vegetation in the Marshall Islands
Author: Radioactivity in the Terrestrial Environment
Author: Publisher: Elsevier
ISBN: 0080474896
Category : Science
Languages : en
Pages : 307
Book Description
The Radioactivity in the Environment Series addresses the key aspects of this socially important and complex interdisciplinary subject. Presented objectively and with the ultimate authority gained from the many contributions by the world's leading experts, the negative and positive consequences of having a radioactive world around us is documented and given perspective. In a world in which nuclear science is not only less popular than in the past, but also less extensively taught in universities and colleges, this book series will fill a significant educational gap. Radioactivity in the Terrestrial Environment presents an updated and critical review of designing, siting, constructing and demonstrating the safety and environmental impact of deep repositories for radioactive wastes. It is structured to provide a broad perspective of this multi-faceted, multi-disciplinary topic providing enough detail for a non-specialist to understand the fundamental principles involved. Contains extensive references to sources of more detailed information Provides a detailed summary of radioactivity in terrestrial ecosystems, providing a substantial and essential reference on the subject Discusses lesser-known sources of radiation exposure that provide useful information for those seeking to place environmental radioactivity into perspective
Long-Term Reduction in 137Cs Concentration in Food Crops on Coral Atolls Resulting from Potassium Treatment
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 34
Book Description
Bikini Island was contaminated March 1, 1954 by the Bravo detonation (U.S nuclear test series, Castle) at Bikini Atoll. About 90% of the estimated dose from nuclear fallout to potential island residents is from cesium-137 (137Cs) transferred from soil to plants that are consumed by residents. Thus, radioecology research efforts have been focused on removing 137Cs from soil and/or reducing its uptake into vegetation. Most effective was addition of potassium (K) to soil that reduces 137Cs concentration in fruits to 3-5% of pretreatment concentrations. Initial observations indicated this low concentration continued for some time after K was last applied. Long-term studies were designed to evaluate this persistence in more detail because it is very important to provide assurance to returning populations that 137Cs concentrations in food (and, therefore, radiation dose) will remain low for extended periods, even if K is not applied annually or biennially. Potassium applied at 300, 660, 1260, and 2070 kg ha−1 lead to a 137Cs concentration in drinking coconut meat that is 34, 22, 10, and about 4% of original concentration, respectively. Concentration of 137Cs remains low 8 to 10 y after K is last applied. An explanation for this unexpected result is discussed.
Uptake of 137Cs by Leafy Vegetables and Grains from Calcareous Soils
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 16
Book Description
Cesium-137 was deposited on Bikini Island at Bikini Atoll in 1954 as a result of nuclear testing and has been transported and cycled in the ecosystem ever since. Atoll soils are of marine origin and are almost pure CaCO3 with high concentrations of organic matter in the top 40 cm. Data from previous experiments with mature fruit trees show very high transfer factors (TF's), [Bq g−1 plant/ Bq g−1 soil, both in dry weight] into fruits from atoll calcareous soil. These TF's are much higher than reported for continental, silica-based soils. In this report TF's for 5 types of leafy vegetable crops and 2 types of grain crops are provided for use in predictive dose assessments and for comparison with other data from other investigators working with other types of soil in the IAEA CRP ''The Classification of Soil Systems on the Basis of Transfer Factors of Radionuclides from Soil to Reference Plants''. Transfer factors for plants grown on calcareous soil are again very high relative to clay-containing soils and range from 23 to 39 for grain crops and 21 to 113 for leafy vegetables. Results from these experiments, in this unique, high pH, high organic content, low potassium (K) soil, provide a boundary condition for models relating soil properties to TF.
Behaviour of 137Cs in the Boreal Forest Ecosystem of Central Sweden
Author: Bulgasem H. FawarisPublisher:
ISBN:
Category : Chernobyl Nuclear Accident, Chornobylʹ, Ukraine, 1986
Languages : en
Pages : 136
Book Description
The Official Guide to Burnham & Cippenham
Author: Publisher:
ISBN:
Category : Burnham (Buckinghamshire, England)
Languages : en
Pages :
Book Description
Energy Research Abstracts
Author: Effect of Potassium on Uptake of 137Cs in Food Crops Grown on Coral Soils
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
In 1954 a radioactive plume from the thermonuclear device code named BRAVO contaminated the principal residential islands, Eneu and Bikini, of Bikini Atoll (11{sup o} 36 minutes N; 165{sup o} 22 minutes E), now part of the Republic of the Marshall Islands. The resulting soil radioactivity diminished greatly over the three decades before the studies discussed below began. By that time the shorter-lived isotopes had all but disappeared, but strontium-90 (9°Sr), and cesium-137, (137Cs) were reduced by only one half-life. Minute amounts of the long-lived isotopes, plutonium-239+240 ({sup 239+240}Pu) and americium-241 (241Am), were present in soil, but were found to be inconsequential in the food chain of humans and land animals. Rather, extensive studies demonstrated that the major concern for human health was 137Cs in the terrestrial food chain (Robison et al., 1983; Robison et al., 1997). The following papers document results from several studies between 1986 and 1997 aimed at minimizing the 137Cs content of annual food crops. The existing literature on radiocesium in soils and plant uptake is largely a consequence of two events: the worldwide fallout of 1952-58, and the fallout from Chernobyl. The resulting studies have, for the most part, dealt either with soils containing some amount of silicate clays and often with appreciable K, or with the short-term development of plants in nutrient cultures.
137Cs Inter-Plant Concentration Ratios Provide a Predictive Tool for Coral Atolls with Distinct Benefits Over Transfer Factors
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 16
Book Description
Inter-plant concentration ratios (IPCR), [Bq g−1 137Cs in coral atoll tree food-crops/Bq g−1 137Cs in leaves of native plant species whose roots share a common soil volume], can replace transfer factors (TF) to predict 137Cs concentration in tree food-crops in a contaminated area with an aged source term. The IPCR strategy has significant benefits relative to TF strategy for such purposes in the atoll ecosystem. IPCR strategy applied to specific assessments takes advantage of the fact tree roots naturally integrate 137Cs over large volumes of soil. Root absorption of 137Cs replaces large-scale, expensive soil sampling schemes to reduce variability in 137Cs concentration due to inhomogeneous radionuclide distribution. IPCR [drinking-coconut meat (DCM)/Scaevola (SCA) and Tournefortia (TOU) leaves (native trees growing on all atoll islands)] are log normally distributed (LND) with geometric standard deviation (GSD) = 1.85. TF for DCM from Enewetak, Eneu, Rongelap and Bikini Atolls are LND with GSD's of 3.5, 3.0, 2.7, and 2.1, respectively. TF GSD for Rongelap copra coconut meat is 2.5. IPCR of Pandanus fruit to SCA and TOU leaves are LND with GSD = 1.7 while TF GSD is 2.1. Because IPCR variability is much lower than TF variability, relative sampling error of an IPCR field sample mean is up 6- to 10-fold lower than that of a TF sample mean if sample sizes are small (10 to 20). Other IPCR advantages are that plant leaf samples are collected and processed in far less time with much less effort and cost than soil samples.
Author: Othmar Horak