カテゴリー「ecology・environment」
Title: Lichen (sp. Cladonia ) as a deposition indicator for transuranium elements investigated with the Chernobyl fallout
Author: Paatero, Jussi / Jaakkola, Timo / Kulmala, Seija
Reference: Journal of Environmental Radioactivity, 38 (2), p.223-247, Jan 1998
doi: 10.1016/S0265-931X(97)00024-6
Kewords: Plutonium, Lichen (Cladonia), Chernobyl fallout
Abstract: The feasibility of employing carpet-forming lichens (sp. Cladonia) as a measure for the deposition of transuranium elements was investigated with the Chernobyl fallout. In Finland, the deposition of these elements after the accident was very uneven. The highest deposition values for 238Pu, 239,240Pu, 241Am, 242Cm and 243,244Cm were 5.7, 3.0, 1.3, 98 and 0.025 Bq m−2, respectively. The amount of deposited 239,240Pu was, however, only some percent of the fallout of the nuclear test explosions of the 1950s and the 1960s. Instead, practically no 242Cm was released into the environment during the weapons’ testing.
URL: http://www.sciencedirect.com/science/article/pii/S0265931X97000246
Title: Long-term decline of 137 Cs concentration in honey in the second decade after the Chernobyl accident
Author: Panatto, Donatella / Gasparini, Roberto / Lai, Piero / Rovatti, Paola / Gallelli, Giovanni
Reference: Science of The Total Environment, 382 (1), p.147-152, Aug 2007
doi: 10.1016/j.scitotenv.2007.03.040
Keywords: 137Cs; Long-term decline; Honey
Abstract: In the years 2001–2004 the 137Cs activity was investigated in a total of 336 samples of different varieties of honey harvested in the Liguria Region of Northern Italy. Our purpose was to define (a) residual radioactive contamination following the Chernobyl accident and 137Cs long-term decline, (b) correlation between 137Cs activity and different honey varieties, and (c) correlation between 137Cs activity and the prevailing geomorphological configuration in the collection areas. The mean 137Cs specific activity was 4.33 ± 5.04 S.D. Bq/kg. Chestnut honey showed higher levels of radioactive contamination, which were ascribed to the extensive, superficial and deep, root apparatus of the tree. Honey samples from acidic argillite soils, which withhold radionuclides after deposition and slowly release them to plants, also showed higher 137Cs activity. Long-term decline was calculated at 456 days, a value lower than those published from different food sources in the years following the accident. The rate of long-term decline decreases with time.
URL: http://www.sciencedirect.com/science/article/pii/S0048969707004044
Title: Near-field radioactive particle dynamics and empirical fallout patterns in Chernobyl’s Western and Northern Plumes
Author: Chesser, Ronald K. / Rodgers, Brenda E.
Reference: Atmospheric Environment, 42 (20), p.5124-5139, Jun 2008
doi: 10.1016/j.atmosenv.2008.02.042
Keywords: Nuclear fuel; Chernobyl; Plume; Particles; Radiation; Settling
Abstract: We compared geographically referenced ground-based measurements of gamma and beta radiation to model predictions of particle dispersion and estimate the influences of particle sizes, wind speeds, and vertical and lateral turbulence on the near-field (40 μm in diameter. These large particulates eliminate passive dispersion of oxidized nuclear fuel and aerosol releases of volatile elements as the primary sources of contamination in the Northern Plume at distances
URL: http://www.sciencedirect.com/science/article/pii/S1352231008001362
Title: Hydrogeological influences on radionuclide migration from the major radioactive waste burial sites at Chernobyl (A review)
Author: Dgepo, S.P. / Skalsky, A.S. / Bugai, D.A. / Marchuk, V.V. [Inst. of Geological Sciences, Kiev (Ukraine)] / Waters, R.D. [Sandia National Labs., Albuquerque, NM (United States)]
Reference: Mar 1994
doi: 10.2172/10135061
Keywords: Radioactive waste disposal, Ukraine, radionuclides, hydrogeology
Abstract: This paper summarizes the recent hydrogeological investigations of several research organizations on waste confinement at the major radioactive waste (RW) burial sites immediately adjacent to the Chernobyl Nuclear Power Plant (Ch. NPP). Hydrogeological conditions and radiologic ground-water contamination levels are described. Ongoing ground-water monitoring practices are evaluated. The chemical and physical characteristics of the radionuclides within the burial sites are considered. Ground water and radionuclide transport modeling studies related to problems of the RW disposal sites are also reviewed. Current concerns on future impacts of the RW burial sites on the hydrological environment and water resources of the Ch.NPP area are discussed.
URL: http://www.osti.gov/bridge/product.biblio.jsp?query_id=2&page=0&osti_id=10135061
Title: Current development of the human and environmental contamination in the Bryansk-Gomel Spot after the Chernobyl accident.
Author: Hille, R / Hill, P / Heinemann, K / Ramzaev, V / Barkovski, A / Konoplia, V / Neth, R
Reference: Radiation and environmental biophysics, 39 (2), p.99-109, Jun 2000
Keywords: contamination, Bryansk-Gomel, soil, food
Abstract: Up to 1991, it was assumed that after the Chernobyl accident in 1986 the time development of radioactive contamination with regard to environment, foodstuff, and man would decrease due to migration processes in the soil, radioactive decay, and protective measures. This assumption was confirmed by all measurements in the first few years after the accident. Since 1991, however, a change in this development has been observed, as many measurements show stagnation or in some cases even an increase of foodstuff and human contamination. If normalised to an average local ground contamination, only a few groups of foodstuffs (e.g., potatoes) show a slight decrease in radioactivity. In this paper, the time development of radioactive contamination in the Bryansk-Gomel Spot on the basis of measurements since 1991 is presented. The consequences for long-term dose assessment are discussed.
URL: http://link.springer.com/journal/411
Title: Effects of non-human species irradiation after the Chernobyl NPP accident
Author: Geras’kin, S.A. / Fesenko, S.V. / Alexakhin, R.M.
Reference: Environment International, 34 (6), p.880-897, Aug 2008
doi: 10.1016/j.envint.2007.12.012
Keywords: Chernobyl NPP accident; Radioactive contamination; Doses; Ecological and biological effects
Abstract: The area affected by the Chernobyl Nuclear Power Plant accident in 1986 has become a unique test site where long-term ecological and biological consequences of a drastic change in a range of environmental factors as well as trends and intensity of selection are studied in natural settings. The consequences of the Chernobyl accident for biota varied from an enhanced rate of mutagenesis to damage at the ecosystem level. The review comprehensively brings together key data of the long-term studies of biological effects in plants and animals inhabiting over 20 years the Chernobyl NPP zone. The severity of radiation effects was strongly dependent on the dose received in the early period after the accident. The most exposed phytocenoses and soil animals’ communities exhibited dose dependent alterations in the species composition and reduction in biological diversity. On the other hand, no decrease in numbers or taxonomic diversity of small mammals even in the most radioactive habitat was shown. In a majority of the studies, in both plant and animal populations from the Chernobyl zone, in the first years after the accident high increases in mutation rates were documented. In most cases the dose–effect relationships were nonlinear and the mutation rates per unit dose were higher at low doses and dose rates. In subsequent years a decline in the radiation background rate occurred faster than reduction in the mutation rate. Plant and animal populations have shown signs of adaptation to chronic exposure. In adaptation to the enhanced level of exposure an essential role of epigenetic mechanisms of gene expression regulation was shown. Based on the Chernobyl NPP accident studies, in the present review attempts were made to assess minimum doses at which ecological and biological effects were observed.
URL: http://www.sciencedirect.com/science/article/pii/S0160412007002474
Title: Accumulation and potential dissolution of Chernobyl-derived radionuclides in river bottom sediment.
Author: Sanada, Yukihisa / Matsunaga, Takeshi / Yanase, Nobuyuki / Nagao, Seiya / Amano, Hikaru / Takada, Hideshige / Tkachenko, Yuri
Reference: Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine, 56 (5), p.751-760, May 2002
Keywords: radionuclides, river, 137Cs, 90Sr
Abstract: Areas contaminated with radionuclides from the Chernobyl nuclear accident have been identified in Pripyat River near the Chernobyl Nuclear Power Plant. The river bottom sediment cores contained 137Cs (10(5)-10(6) Bq/m2) within 0-30 cm depth, whose concentration is comparable to that in the ground soil in the vicinity of the nuclear power plant (the Exclusion Zone). The sediment cores also accumulated 90Sr (10(5) Bq/m2), (239,240)Pu (10(4) Bq/m2) and 241Am (10(4)Bq/m2) derived from the accident. Several nuclear fuel particles have been preserved at 20-25 cm depth that is the peak area of the concentrations of the radionuclides. These inventories in the bottom sediments were compared with those of the released radionuclides during the accident. An analysis using a selective sequential extraction technique was applied for the radionuclides in the sediments. Results suggest that the possibility of release of 137Cs and (293,240)Pu from the bottom sediment was low compared with 90Sr. The potential dissolution and subsequent transport of 90Sr from the river bottom sediment should be taken into account with respect to the long-term radiological influence on the aquatic environment.
URL: http://www.ncbi.nlm.nih.gov/pubmed/11993951?dopt=Abstract
Title:Specific activity and activity ratios of radionuclides in soil collected about 20 km from the Fukushima Daiichi Nuclear Power Plant: Radionuclide release to the south and southwest.
Author: Tagami, Keiko / Uchida, Shigeo / Uchihori, Yukio / Ishii, Nobuyoshi / Kitamura, Hisashi / Shirakawa, Yoshiyuki
Reference: The Science of the total environment, 409 (22), p.4885-4888, Oct 2011
doi: http://dx.doi.org/10.1016/j.scitotenv.2011.07.067
Keywords: Radioactivity ratio; Fukushima Daiichi Nuclear Power Plant; Soil; Cesium-137; Cesium-134; Iodine-131
Abstract: ► Soil samples were collected at about 20 km south of Fukushima Daiichi Nuclear Power Plant. ► The concentrations of 131I, 134, 136, 137Cs and 129mTe were obtained, but 103Ru was not. ► This suggests that noble gasses and volatile radionuclides predominated in the releases. ► Activity ratio of 134Cs/137Cs from the power plant to the south was abound 0.90.
URL: http://www.ncbi.nlm.nih.gov/pubmed/21906779?dopt=Abstract
Title: Resuspension of coarse fuel hot particles in the Chernobyl area
Author: Wagenpfeil, Florian / Tschiersch, Jochen
Reference: Journal of Environmental Radioactivity, 52 (1), p.5-16, Jan 2001
doi: 10.1016/S0265-931X(00)00081-3
Keywords: Resuspension; Chernobyl fallout; Hot particles; Aerosol sampler; Digital autoradiography
Abstract: Measurements of resuspended aerosol in the Chernobyl 30-km exclusion zone have shown coarse fuel hot particles in the activity range 1–12 Bq per particle. The particles were sampled with newly designed rotating arm impactors which simultaneously collect during the same experiment three samples with fuel particles in the size ranges larger than 3 μm, larger than 6 μm and larger than 9 μm in geometric diameter. The radionuclide ratios, determined after γ-spectrometry, were in good agreement with the theoretical calculations for the radionuclide-composition of the Chernobyl Nuclear Power Plant at the moment of the accident and the measured hot particles in soil in the early years after the accident. The number concentrations of airborne hot particles were derived from digital autoradiography. For wind resuspension, maximal concentrations of 2.6 coarse hot particles per 1000 m3 and during agricultural activities 36 coarse hot particles per 1000 m3 were measured. The geometric diameter of single hot particles was estimated to be between 6 and 12 μm.
URL: http://www.sciencedirect.com/science/article/pii/S0265931X00000813
Title: Numerical simulation for a long-range dispersion of a pollutant using Chernobyl data
Author: Suh, Kyung-Suk / Han, Moon-Hee / Jung, Sung-Hee / Lee, Chang-Woo
Reference: Mathematical and Computer Modelling, 49 (1-2), p.337-343, Jan 2009
doi: 10.1016/j.mcm.2008.01.008
Keywords: Lagrangian particle model; Chernobyl; Sensitivity studies; Mixing height
Abstract: A Lagrangian particle model has been developed and applied to a long-range atmospheric dispersion. The developed numerical model has been tested by comparing its predictions with the 137Cs air concentrations recorded over European areas during the Chernobyl accident. Sensitivity studies were performed to investigate the numerical accuracy according to a variation of the parameters such as the mixing height and diffusion coefficient in the model. From a comparative study, the calculated concentration distributions were more sensitive to a variation of the mixing height than to the changes of the diffusion coefficient values. Also, the calculated concentrations agreed with the time series of the measured ones at some sampling points.
URL: http://www.sciencedirect.com/science/article/pii/S0895717708000459
