タグ「240Pu」
Title: 90Sr, 238U, 234U, 137Cs, 40K and 239/240Pu in Emmental type cheese produced in different regions of Western Europe
Author: P. Froidevaux, , J.-J. Geering, L. Pillonel, J.-O. Bosset, J.-F. Valley
Reference: Journal of Environmental Radioactivity, Volume 72, Issue 3, 2004, Pages 287–298
DOI: http://dx.doi.org/10.1016/S0265-931X(03)00179-6
Keywords: Strontium-90; Cheese; Uranium isotopes; Milk-to-cheese transfer; Food authenticity
Abstract: A method is presented for the determination of 90Sr and uranium in Emmental type cheese collected in dairy plants from different European countries. Results display a significant correlation (r=0.708, Student t-test=6.02) between the 90Sr content of the cheese and the altitude of grazing. The highest 90Sr activity is 1.13 Bq kg−1 of cheese and the lowest is 0.29 Bq kg−1. Uranium activity is very low with a highest 238U value of 27 mBq kg−1. In addition, 234U/238U ratio shows a large enrichment in 234U for every location. Without any significant indication of the geographic origin of the cheese, this enrichment is believed to be due to the geological features of the pasture, soil and underground water. These results tend to prove that the contamination of milk by uranium originates principally from the water that the cows drink instead of the forage. This finding may have a great importance in models dealing with dairy food contamination by radionuclides following a nuclear accident. Also, the 90Sr content and to a lesser extent the 234U/238U ratio could be used to trace the authenticity of the origin of the cheese. 137Cs activity is lower than the detection limit of 0.1 Bq kg−1 in all the samples collected (n=20). Based on natural 40K activity in cheese (15–21 Bq kg−1), the decontamination factor for the alkaline cations from milk to cheese is about 20. Plutonium activity stays below the detection limit of 0.3 mBq kg−1.
ＵＲＬ：http://www.sciencedirect.com/science/article/pii/S0265931X03001796
Title: On peculiarities of vertical distribution of 239,240Pu, 238Pu and 137Cs activity concentrations and their ratios in lake sediments and soils
Author: B. Lukšienė, E. Maceika, N. Tarasiuk, E. Koviazina, V. Filistovič, Š. Buivydas, A. Puzas Reference: Journal of Radioanalytical and Nuclear Chemistry , February 2014
DOI: 10.1007/s10967-014-3026-0
Keywords: 238Pu, 239,240Pu, 137Cs, Origin, Lake sediments, Upland and flooded soils, Vertical profiles
Abstract: Distributions of 239,240Pu, 238Pu and 137Cs activity concentrations in the cores of sediments in the shallow lake, flooded and upland forest soils taken in the vicinity of Vilnius city were analyzed. The radiochemical, α-spectrometric and mass spectrometric methods were used for the plutonium evaluation and γ-spectrometry was used for the radiocesium evaluation. The only peak of enhanced radionuclide activity concentrations was determined for the lake bottom sediments, whereas vertical profiles of the radionuclide activity concentrations in flooded and upland forest soil cores were distinguished by two peaks. The obtained values of the activity concentration ratio 238Pu/239,240Pu and the isotopic ratio 240Pu/239Pu indicated that the global fallout was a source of plutonium in the investigated environment. Chernobyl-derived radiocesium was detected solely in the surface layers (2–11 cm) of the studied sample cores. The contribution of the Chernobyl deposits amounted to about 2.26, 6.11 and 20.9 % of the total radiocesium inventory in the bottom sediments, the upland soil and flooded soil, respectively.
ＵＲＬ：http://link.springer.com/article/10.1007/s10967-014-3026-0
Author: Gudkov D.I., Nazarov A.B., Dzyubenko E.V., Kaglyan A.E., Klenus V.G.
Reference: Gazette “РАДИАЦИОННАЯ БИОЛОГИЯ. РАДИОЭКОЛОГИЯ “ (Radiation Biology, Radioecology), 2009
ISSN: 0869-8031
DOI: 10.1134/S0869803109060095
Keywords: freshwater mussels, contamination
Abstract: Observes the concentration of radionuclides of 90Sr, 137Cs, 238Pu, 239 + 240Pu и 241Am in freshwater mussels in the exclusion zone of Chernobyl. Analyzes radiation doses, frequency of chromosomal aberrations and composition of hemolymph in Lymnaea Stagnalis.
URL: http://elibrary.ru/item.asp?id=12989734
Title: Migration ability of radionuclides in soil-vegetation cover of Belarus after Chernobyl accident
Author: G.A. Sokolik, T.G. Ivanova, S.L. Leinova, S.V. Ovsiannikova, I.M. Kimlenko
Reference: Environment International, Volume 26, Issue 3, January 2001, Pages 183-187
DOI: http://dx.doi.org/10.1016/S0160-4120(00)00104-5
Keywords: Radionuclides; Cesium-137; Strontium-90; Plutonium-239, 240; Americium-241; “hot” particles; Physicochemical State; Chernobyl accident; Migration parameters; Biological accessibility
Abstract: This paper illustrates the experimental experience achieved in the research of the self-restoration of radioactive-contaminated natural ecosystems. The main directions of studies were: the content and geochemical stability of “hot” particles in radioactive fallout from Chernobyl accident; the physicochemical forms (water-soluble, exchangeable, mobile and fixed) of Cs-137, Sr-90, Pu-239, 240 and Am-241 in the wide varieties of soils; the biological accessibility of radionuclides and their contents in soil pore solutions; and the dynamics and migration parameters of radionuclides vertical redistribution in different landscape conditions.
URL: http://www.sciencedirect.com/science/article/pii/S0160412000001045
Title: Levels and trends of radioactive contaminants in the Greenland environment
Author: Henning Dahlgaard, Mats Eriksson, Sven P. Nielsen, Hans Pauli Joensen
Reference: Science of the Total Environment. Sep2004, Vol. 331 Issue 1-3, p53-67. 15p.
DOI: http://dx.doi.org/10.1016/j.scitotenv.2004.03.023
Keywords: Caesium-137; Strontium-90; Technetium-99; Plutonium-239-240; Polonium-210; Greenland; Environmental radioactivity
Abstract: Levels of radioactive contaminants in various Greenland environments have been assessed during 1999–2001. The source of 137Cs, 90Sr and 239,240Pu in terrestrial and fresh water environments is mainly global fallout. In addition, the Chernobyl accident gave a small contribution of 137Cs. Reindeer and lamb contain the largest observed 137Cs concentrations in the terrestrial environment—up to 80 Bq kg−1 fresh weight have been observed in reindeer. Due to special environmental conditions, 137Cs is transferred to landlocked Arctic char with extremely high efficiency in South Greenland leading to concentrations up to 100 Bq kg−1 fresh weight. In these cases very long ecological half-lives are seen. Concentrations of 99Tc, 137Cs and 90Sr in seawater and in marine biota decrease in the order North-East Greenland and the coastal East Greenland current>South-West Greenland>Central West Greenland and North-West Greenland>Irmiger Sea∼Faroe Islands. The general large-scale oceanic circulation combined with European coastal discharges and previous contamination of the Arctic Ocean causes this.
URL: http://www.sciencedirect.com/science/article/pii/S0048969704002025
