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Sample records for 137cs radionuclide excretion

  1. Distribution of 137Cs radionuclide in industrial wastes effluents of Gresik, East Java, Indonesia

    The distribution of anthropogenic radionuclides 137Cs was measured from industrial waste effluent of Gresik to Gresik Sea in east Java, Indonesia. The activity of 37Cs detected at all stations was much lower than in northeast Japan both before and after NPP Fukushima accident. This indicated that in Gresik industrials waste did not consist of 137Cs. The lowest activity 137Cs occurred at the station nearest to the industrial waste effluent that contained some particle ions that were able to scavenge 137Cs and then precipate this radionuclide. Furthermore, the greatest 137Cs occurred at the station that has high current speeds that stirred up sediment to release 137Cs in seawater as a secondary source. The lowest salinity did not effect on the activity of 137Cs even though the lowest salinity and activity 137Cs occurred at the same station. (author)

  2. Distribution of 137Cs Radionuclide in Industrial Wastes Effluents of Gresik, East Java, Indonesia

    Muslim

    2015-04-01

    Full Text Available The distribution of anthropogenic radionuclides 137Cs was measured from industrial waste effluent of Gresik to Gresik Sea in east Java, Indonesia. The activity of 37Cs detected at all stations was much lower than in northeast Japan both before and after NPP Fukushima accident. This indicated that in Gresik industrials waste did not consist of 137Cs. The lowest activity 137Cs occurred at the station nearest to the industrial waste effluent that contained some particle ions that were able to scavenge 137Cs and then precipate this radionuclide. Furthermore, the greatest 137Cs occured at the station that has high current speeds that stirred up sediment to release 137Cs in seawater as a secondary source. The lowest salinity did not effect on the activity of 137Cs even though the lowest salinity and activity 137Cs occured at the same station

  3. Investigation of radionuclide 137Cs sorption by natural and synthetic zeolites

    Sorption-selective properties of natural zeolite-clinoptilolite, from the Sokirnitsky deposit of Ukraine, and synthetic zeolites relatively to radionuclide 137Cs and depending on pH and temperature were studied. A high sorption ability of clinoptilolite relatively to 137Cs was determined

  4. Accumulation and Elimination of 137Cs Radionuclide by gold fish (Cyprinus Carpio)

    A study to estimate accumulation and elimination of 137Cs radionuclide by gold fish (Cyprinus Carpio) has been carried out. The experiment used aquarium as a cultivating media. Gold fish was placed into aquarium filled with 70 liter of water and 137Cs concentration of 10 Bq/ml. From the observing time of 40 days it was found that activity concentration in fish became saturated in 30th day. Saturation after the 30th day was confined by additional observation using 137Cs concentration of 5 and 15 Bq/ml. Saturated concentration fish was then transfered to inactive aquarium to determine is elimination rate. Transfer factor, i.e. the ratio of 137Cs concentration in fish to that in water, was found to be (12.99+0.28) ml/g, whereas the elimination rate of 137Cs was found to be 0.046 day, which correspond to a biological half life of 15 days

  5. Precipitation scavenging of 7Be and 137Cs radionuclides in air

    Atmospheric depositional fluxes of the naturally occurring 7Be of cosmogenic origin and 137Cs from fallout of the Chernobyl accident were measured over a 6-year period (January 1987-December 1992) at Thessaloniki, Greece (40o38'N, 22o58'E). Total precipitation accumulation during 1987-1992 varied between 33.7 cm and 65.2 cm, reflecting a relatively dry (precipitation-free) climate. The activity concentrations of 7Be and 137Cs in rainwater depended on the precipitation rate, being higher for low precipitation rates and lesser for high precipitation rates. 137Cs was removed by rain and snow more efficiently than 7Be. Snowfall was more efficient than rainfall in removing the radionuclides from the atmosphere. The annual bulk depositional fluxes of 7Be varied between 477 and 1133 Bq m-2 y-1 and this variability was attributed to the amount of precipitation and the variations of the atmospheric concentrations of 7Be. The annual bulk depositional fluxes of 137Cs showed a significant decrease over time from 1987 to 1992, resulting in a removal half-life of 1.33 years. The presence of 137Cs in air, and therefore in rainwater and snow, long after the Chernobyl accident (26 April 1986) was mainly due to the resuspension process. The normalized depositional fluxes of both radionuclides showed maximal values during the spring season where the maximum amount of precipitation occurred. The relatively high positive correlation between 7Be and 137Cs normalized depositional fluxes indicates that the scavenging process of local precipitation controlled the fluxes of both radionuclides. The dry depositional flux of 7Be was less than 9.37% of total (wet and dry) depositional flux. The fraction of dry-to-total depositional flux of 137Cs was much higher than that of 7Be, due to the resuspended soil

  6. Studying sorption properties of a mixture of natural and synthetic zeolites in respect of radionuclides 137Cs and 90Sr

    Sorption properties of a mixture of zeolites (natural and synthetic) in respect of radionuclides 137Cs and 90Sr are studied. The influence of additions on the sorption properties of clinoptilolite and mixture of zeolites (natural and synthetic) is studied

  7. Use of 137Cs and other fallout radionuclide in soil erosion investigations: progress, problems and prospects

    Accelerated erosion and soil degradation currently represent serious problems for the global environment. Against this background there is a need to assemble reliable information on the rates of soil loss involved. Existing techniques for documenting rates of soil loss possess many limitations and there is increasing interest in the potential for using fallout radionuclides, particularly 137Cs, to obtain such information. An example of the application of the 137Cs approach to a cultivated field at Rufford Forest Farm, Nottinghamshire, UK, is presented to illustrate its value. The key advantages of the approach are that it provides a means of assembling retrospective estimates of medium-term (ca. 40 years) rates of soil loss and the spatial pattern of erosion and deposition involved, on the basis of a single site visit. There are, however, currently a number of problems and uncertainties associated with the use of 137Cs in soil erosion investigations, and these are reviewed and needs for further research identified. Potential developments of the approach, including the use of other fallout radionuclides such as unsupported 210Pb and 7Be are also considered. (author)

  8. Accumulation of 137Cs and 90Sr radionuclides by leguminous plants of various species and varieties

    Decision of protein problem on territories contaminated with radionuclides as a result of the accident at the Chernobyl NPP is not possible without extension of lands under cultivation of leguminous plants (peas, lupine and soybean). All lupine varieties show high indices of radionuclides accumulation and are restrictedly acceptable for production on contaminated territories. The following varieties of yellow forage lupine are the most acceptable for cultivation on the contaminated territories: Zhemchug, Rannij, Adradzhenne, Mitan. Introduction of varieties with the low level of radionuclides accumulation (peas — Aist, Agat, Gomelskaya; soybean — Mageva, Pina, Severnaya zvezda) into agricultural production will make to possible to obtain agricultural products meeting the requirements of the “Republican permissible levels of 137Cs and 90Sr content in agricultural raw materials and forages” on arable lands with the higher density of radioactive contamination: 137Cs — 925—1110 kBq/m2 (25-30 Ci/km2) and 90Sr 15—18 kBq/m2 (0.40-0.50 Ci/km2)

  9. Natural radionuclides and 137Cs in moss and lichen in eastern Serbia

    Čučulović Ana

    2012-01-01

    Full Text Available The paper presents the results of radionuclides determination in moss (Homolothecium sp., Hypnum Cupressiforme sp., and Brachythecium sp. and lichen (Cladonia sp. sampled in the region of Eastern Serbia during 1996-2010. The activities in moss are in the range of 100-500 Bq/kg d. w. for 40K, and 5-50 Bq/kg d. w. for 226Ra and 232Th, while the “soil-to-moss” transfer factors are 0.45 for 40K, 3 for 226Ra, and 0.3 for 232Th. The spatial distribution of the 137Cs activities is highly non-uniform; some values reach 500 Bq/kg d. w., with less than 10% of the samples, mainly the ones taken prior to 2000, with the activity above 1000 Bq/kg d. w. The variations in the content of natural radionuclides among the moss species are not significant. The frequency pattern of the activities of natural radionuclides in lichen is similar to the one in moss, but the activities in lichen are to some extent lower. The mean activity of 137Cs in lichen is below 400 Bq/kg d. w. The mean activities of 7Be in moss and lichen sampled in 2006 and 2008 are in the range of 41-122 Bq/kg d. w., with pronounced variations between the sampling sites.

  10. Distribution of natural radionuclides and 137Cs in soils of southwestern Ontario

    In Canada and the United States approximately 82% of the annual total dose of radiation to any person comes from terrestrial and cosmogenic sources. The soil is also the main source of radon exposure to humans. Therefore it is important to know the background levels of natural and anthropogenic radioactivity in soils. In this study the radionuclides 40K, 226Ra, 232Th and 137Cs were measured in the soils of southwestern Ontario in order to determine the background levels and to understand the soil profile distribution. Clay content is the most important variable affecting the background levels of 40K, 226Ra, and 232Th in the soil. The profile distribution of these radionuclides is further influenced by pedogenic processes, particularly carbonate leaching from the solum and clay illuviation from the Ae to the Bt horizons. The lateral and vertical distribution of bomb-fallout 137Cs is influenced by soil management such as tillage, biopedoturbation by soil animals such as earthworms and groundhogs, soil erosion and soil organic matter cycling. Multiple regression analysis showed that clay content, sand content, percent CaCO3, pH and organic carbon content had variable influences on each of the radionuclide contents in the soil. (author)

  11. Natural radionuclides and 137Cs in commercialized edible mushrooms in Sao Paulo-Brazil

    Artificial and natural radionuclides are commonly found in several compartments of the earth's crust. Some mushroom species have a high capacity to absorb radionuclides and toxic elements from the soil. Diet is considered as one of the main routes of radioactive contamination. Therefore, radioactivity measurements in the environment and in food are extremely important to monitor the radiation levels that human can be exposed to either directly or indirectly. Environmental bio monitoring has demonstrated that diverse organisms such as crustaceans, fish and mushrooms are useful when evaluating both the contamination and the quality of the ecosystems. There are actually several radionuclides that can be accumulated in mushrooms, including 40K, 137Cs, 232Th and 238U. There are few studies in the Southern hemisphere countries, on the natural and artificial radioactivity levels in mushrooms. The present study evaluated 40K, 137Cs, 232Th and 238U in commercialized edible mushrooms in the state of Sao Paulo, Brazil. The edible mushroom samples were acquired in different commercial establishments in the Sao Paulo metropolitan region, specifically in Municipal Markets. Some samples were acquired directly from producers located in the cities of Mogi das Cruzes, Mirandopolis, Suzano and Juquitiba. About 400g were collected for each edible mushroom species, which included Agaricus sp, Pleurotus sp and Lentinula sp species. All the samples were prepared and stored in polyethylene bottles for approximately 35 days, so that secular equilibrium could be established before counting. The 40K, 137Cs, 232Th and 238U gamma activities were measured by gamma spectrometry. The equipment consisted of a Hyper pure Germanium detector connected to an electronic system. The detector efficiency was obtained from measurements of reference materials: IAEA-300, IAEA-327 and IAEA-375. The results for the specific activities in edible mushrooms samples ranged fi-om 461 to 1535 Bq kg-1, 1.4 to 10.6 Bq

  12. Adsorption models of {sup 137}Cs radionuclide and Sr (II) on some Egyptian soils

    Kamel, Nariman H.M., E-mail: Narimankamel@hotmail.co [Radiation Protection Department, Nuclear Research Center, Atomic Energy Authority, P.O. Box 13759, Cairo (Egypt)

    2010-04-15

    Distribution of cesium ({sup 134}Cs and {sup 137}Cs) and strontium (Sr-II) between soil/water phases depends on many factors such as concentration of these ions between phases, the cation exchange capacity (CEC) of the soil as well as its clay content, chemical composition (especially Na, K, Ca, and Mg ions), grain size distribution, calcite, iron oxide content, and organic coatings. Distribution coefficients (Kd) of cesium (labeled with {sup 137}Cs) and strontium were measured on the grain size distributions >=32 mum of four soil samples. These soils were obtained from four different locations within Inshas site in Egypt and three groundwater samples were obtained from the same site locations. X-ray diffraction showed that the soil samples consisted mainly of quartz mixed with the minor amounts of kaolonite and clay minerals. Sorption experiments were carried out at strontium aqueous concentrations range 10{sup -7} to 10{sup -4} mol l{sup -1}. The CEC and Kds for cesium and strontium were measured at the same metal concentrations range. Distribution coefficients of cesium were found to be influenced by the composition of the soil, while the distribution coefficients of strontium were found to depend on calcium concentrations in the soil/groundwater system. The aim of this study was to determine the safety assessment of disposal {sup 137}Cs radionuclide and Sr(II) in the aquifer regions inside the Inshas site. Sequential extraction tests showed that, strontium was associated with the carbonate fractions and majority of cesium was sorbed on the iron oxides and the residue.

  13. Mathematical Modelling of Immobilization of Radionuclides 137Cs and 60Co in Concrete Matrix

    Transport phenomena involved in the leaching of a radioactive material from a cement composite matrix are investigated using an empirical method employing a polynomial equation. To assess the safety for disposal of radioactive waste-cement composition, the leaching of 137Cs and 60Co, from a waste composite into a surrounding fluid has been studied. Leaching tests were carried out in accordance with a method recommended by IAEA . Determination of retardation factors, KF and coefficients of distribution, kd, using a simplified mathematical model for analyzing the migration of radionuclides, has been developed. Transport phenomena involved in the leaching of a radioactive material from a cement composite matrix are investigated using an empirical method employing a polynomial equation. In our experiment we have analyzed mechanism of 137Cs and 60Co leaching values during a period of 60 days. Results presented in this paper are examples of results obtained in a 25 year mortar and concrete testing project, which will influence the design of the engineered trenches system for a future central Serbian radioactive waste storage center.(author).

  14. RADIONUCLIDES BEHAVIOUR MODELLING OF 137CS AND 90SR IN GLYBOKE AND DALEKE LAKES OF CHERNOBYL EXCLUSION ZONE

    Yuri Kutlakhmedov

    2013-04-01

    Full Text Available  Results of 137Cs and 90Sr radionuclides behaviour modelling, which are the most spread radioisotopes in water bodies of Chernobyl Exclusion Zone are represented. Dynamics of radionuclides activity is modelled in water body components as the percentage of their total stock. Quantitative transfer of the radionuclides between water body components in the Chernobyl Exclusion Zone is determined and predicted. 

  15. Electrochemical treatment of aqueous radioactive solutions containing 137Cs and 260Co radionuclides

    Electrochemical treatment of simulated aqueous radioactive solutions containing 137Cs /or 60Co radionuclides had been investigated. In this study, the used electrolytic cell was made from plexiglas of outer and inner dimensions 12.5x5.8x6.5 cm, and 11.2x4.8x5.7 cm, respectively. In the cell, the employed anodes were of the shape of metal plates fabricated from industrial wastes of Al, Fe, and Cu with effective dimensions of 4.0x2.8x0.1 cm (surface area = 11.2 cm2). The used cathode was made from a platinum sheet of dimensions 4.0x0.5x0.05 cm(surface area = 2.0 m2). the distance between the electrodes was kept constant at 10 cm. Direct electric current was supplied from a digital DC-power supply of maximum applied voltage 30V and electric current 3A. In this work, the investigated factors were: applied voltage and the type of the used anode, treatment duraton, hydrogen ion concentration, salt content of the aqueous solution, and the effect of the presence of different concentrations from the non-active cesium and cobalt salts. It was observed that the highest percent of removal (Pr) for 137Cs after a treatment duration of 20 minutes was 79%, 69% and 60% using AI, Fe, and Cu anodes, respectively. Also, the highest Pr values for 60Co after 15 minutes were 98%, 95% and 93%, reached using Al, Fe, and Cu anodes, respectively

  16. Distribution of the radionuclide 137Cs in the soils of a wet mountainous forest in Taiwan

    The behavior of 137Cs was studied in the Yuanyang lake ecosystem, a wet mountainous forest in subtropical Taiwan. Soils investigated are either partially podzolic soils or nearly pure peats with a high organic matter concentration in the surface layer. Concentration of 137Cs was highest in the organic surface layers, particularly in the Oe horizon or in the underlying A horizon. The downwards migration to the mineral horizons is limited, in spite of the high rainfall. Topography is a critical factor for the distribution of 137Cs. It is shown that the concentration of 137Cs is highest at the foot of the slope and lower near the summit and near the lakeshore. The variation of the concentration along the landscape has been attributed to erosion-deposition in combination with surface run-off of the undisturbed forest. The amount of 137Cs in the site studied is significantly higher than at any other place in Taiwan. The accumulation of 137Cs is attributed to the high rainfall, which brought large amounts of 137Cs with the precipitation in the early 1960s. A very remarkable feature of the ecosystem is that 137Cs is not leached to the subsoils, but is stored in the biomass. Due to permanent recycling it remains available, without being leached downward

  17. Transfer factors of natural radionuclides and (137)Cs from soil to plants used in traditional medicine in central Serbia.

    Djelic, Gorica; Krstic, Dragana; Stajic, Jelena M; Milenkovic, Biljana; Topuzovic, Marina; Nikezic, Dragoslav; Vucic, Dusica; Zeremski, Tijana; Stankovic, Milan; Kostic, Dragana

    2016-07-01

    Transfer factors of natural radionuclides and (137)Cs from soil to plants used in traditional medicine were determined. The transfer factors (TF) were calculated as Bq kg(-1) of dry plant per Bq kg(-1) of dry soil. Mass activity concentrations of (226)Ra, (232)Th, (40)K and (137)Cs in soil and plant samples were measured with high purity germanium detector (HPGe). The concentrations of As, Co, Cr, Cu, Mn, Ni, Pb and Zn were determined, as well as the cation exchange capacity (CEC) and the content of exchangeable cations (Ca, Mg, K, Na). Wide ranges of values were obtained for all the metals, especially for Cr and Ni. The Absalom model was used for determination of the amount of (137)Cs transferred from soil to plant based on soil characteristics such as pH, exchangeable potassium, humus and clay contents. The estimated transfer factors were in the range from 0.011 to 0.307 with an arithmetic mean of 0.071, median of 0.050, geometric mean of 0.053 and geometric standard deviation (GSD) of 2.08. This value agreed well with that calculated from the measurements of 0.069, geometric mean 0.040 and GSD 3.19. Correlations between radionuclides, metals, physicochemical properties and transfer factors were determined by Spearman correlation coefficient. There was a strong positive correlation between (137)Cs transfer factor and the ratio of transfer factor for K and (137)Cs. Principal Component Analysis (PCA) was performed in order to identify some pattern of data. PMID:27082759

  18. Removal of radionuclides 137Cs and 90Sr by oats from sod-podzolic loamy sand soil

    In the conditions of the Republic of Belarus in course of the research there was realized evaluation of the most popular recognized varieties of oat (Avena sativa) by their yielding capacity, degree of 137Cs and 90Sr accumulation for the selection of the most efficient varieties which promoted lowing of internal radiation doses in population. In the course of the study there was analysed data on crop yield of oat, specific activity of 137Cs and 90Sr in grain and straw, total removal of radionuclide 137Cs and potassium, 90Sr and calcium. The research was realized in field conditions in a region which was directly injured from action of Chernobyl Nuclear Power Plant – at a Collective Farming Unitary Enterprise 'Strelichevo' (Khojniki, Gomel region, Belarus). The experiments were carried out on sod-podzolic light loamy soil, underlaid from the depth of 0.7 m with moraine clay loam. Agrochemical characteristics of trial plot soil were the following: pH (KCl) - 5.95, mobile phosphorous forms P2O5 (0.2n HCl, according to Kirsanov) - 197 mg/kg and K2O (0.2n HCl, according to Kirsanov) -288 mg/kg of soil, exchangeable calcium forms (Ca) (1 M KCl, according to Mazaeva, Neugodova ) - 542650 mg/kg and Mg - 94-176 mg/kg of soil, humus content (0.2n K2Cr2O7, according to Tyurin) – 1.9%. Soil contamination density by radionuclide 137 Cs – 320 kBk/square m, 90 Sr – 30 kBk/square m. Proceeding crop - meadow clover (Trifolium pratense L.). As a result of realized research there was revealed data of zoning and potential five oats varieties at its cultivation on lands contaminated by radionuclide 137Cs and 90Sr. Research results showed that on contaminated onl;y with 137Cs it was more efficient to grow Chakal and Alf oat varieties, and for soils contaminated only with 90Sr the best varieties were Dukat and Alf. In case of soil contamination with both radionuclides – Alf

  19. Depth profiles of environmental radionuclides (40K, 226Ra, 210Pb and 137Cs) in temperate forest soils in Germany

    Depth profiles of environmental radionuclides (40K, 226Ra, 210Pb and 137Cs) were investigated in several temperate forest soils in Germany to estimate heterogeneity of the soil horizon of interest. Absolute values of the activity concentrations of these nuclides varied to a large extent depending on the properties of individual forests as well as local geology. Activity concentrations of 40K increased with increasing soil density reflecting that most potassium is contained in mineral components of the soil. The variations in the 40K activity with depth may relate to biological activities in subsoil, such as root uptake of the nutrients. Consequences of bioturbation could be deduced from variability in vertical profiles of the environmental radionuclides like 137Cs and 210Pb. (author)

  20. Standardization of radionuclides 45Ca, 137Cs, 204Tl by tracing method using 4πβ-γ coincidence system

    The procedure followed for the standardization of 45Ca, 137Cs and 204Tl is described. The activity measurements was carried out in a 4πβ-γ coincidence system by the tracing method. The radionuclides chosen as the P-y emitting tracer nuclide were 60Co for the 45Ca and 134Cs for 137Cs and 204TL because their end-point beta-ray energy are close to the respective beta emitters. The radioactive sources were prepared using two different techniques: one was the drops technique and the other was the solution technique. In the drop technique the sources were prepared by dropping directly on the subtract both solutions (tracer and beta pure). In the other technique a solution of tracer plus beta pure was mixed previously before making the radioactive sources. The activities of the radionuclides obtained with these technique were compared and the values are in agreement within the experimental uncertainties. (author)

  1. Radiological Dose Assessment for the Radionuclides 90Sr and 137Cs Around the TRIGA Mark II Research Reactor

    An attempt has been taken in the work to assess the radiological consequence due to the deposition of 90Sr and 137Cs on ground, vegetation, milk and meat. The source term and release rate for the radionuclides as well as air concentration as a function of downwind distance from the reactor core have been investigated for a hypothetical accident. The maximum air concentration has been estimated which was found to be in southern direction and at 100 m distance from the core of the reactor. Then the ground concentration, concentration in vegetation, milk and meat as well as probable doses to the member of public through ground deposition, ingestion of vegetation, milk and meat only for the aforementioned radionuclides have also been estimated. The maximum dose rates due to 137Cs, 90Sr and 137Sr + 90Sr for all the pathways were found to be 0.0275, 0.0296 and 0.0560 μSv/hr, respectively. The maximum dose due to 137Cs + 90Sr was within the background limit (0.25μSv/hr). Dose values to the member of the public due to release of these two radionuclides are not singnificant.(author)

  2. ESTIMATION OF SOIL EROSION IN A RESERVOIR WATERSHED USING 137CS FALLOUT RADIONUCLIDE

    Y. J. CHIU; A. M. BORGHUIS; H. Y. LEE; K. T. CHANG; J. H. CHAO

    2007-01-01

    Sedimentation from soil erosion is a critical reservoir watershed management issue. Due to the difficulty of field investigations, empirical formulas are commonly used to estimate the soil erosion rate. However, these estimations are often far from accurate. An effective alternative to estimating soil erosion is to analyze the spatial variation of 137Cs inventory in the soil. 137Cs can be adsorbed by the soil and is widely assumed to change its distribution only when disturbed by rainfall and human activities. Thus, 137Cs distributed in soils can be a useful environmental tracer to estimate soil erosion. In this study, the net soil loss estimate is 108,346 t/yr and the gross erosion and net erosion rates are 10.1 and 9 t/ha yr respectively. The sediment delivery ratio is therefore estimated to be 0.9 based on the two erosion rates. Because of the steep hillsides in the watershed, only 10% of the sediment yield stayed in the deposition sites and 90% was transported to the river as the sediment output. Soil erosion estimates from spatial variations of the 137Cs activity in the Baishi river watershed showed satisfactory accuracy when compared to sediment yield data. Using soil 137Cs concentrations is therefore a feasible method for estimating soil loss or deposition in Taiwan. Data sampling, analysis and result of this approach are given in this paper.

  3. Measurement of fallout radionuclides, (239)(,240)Pu and (137)Cs, in soil and creek sediment: Sydney Basin, Australia.

    Smith, B S; Child, D P; Fierro, D; Harrison, J J; Heijnis, H; Hotchkis, M A C; Johansen, M P; Marx, S; Payne, T E; Zawadzki, A

    2016-01-01

    Soil and sediment samples from the Sydney basin were measured to ascertain fallout radionuclide activity concentrations and atom ratios. Caesium-137 ((137)Cs) was measured using gamma spectroscopy, and plutonium isotopes ((239)Pu and (240)Pu) were quantified using accelerator mass spectrometry (AMS). Fallout radionuclide activity concentrations were variable ranging from 0.6 to 26.1 Bq/kg for (137)Cs and 0.02-0.52 Bq/kg for (239+240)Pu. Radionuclides in creek sediment samples were an order of magnitude lower than in soils. (137)Cs and (239+240)Pu activity concentration in soils were well correlated (r(2) = 0.80) although some deviation was observed in samples collected at higher elevations. Soil ratios of (137)Cs/(239+240)Pu (decay corrected to 1/1/2014) ranged from 11.5 to 52.1 (average = 37.0 ± 12.4) and showed more variability than previous studies. (240)Pu/(239)Pu atom ratios ranged from 0.117 to 0.165 with an average of 0.146 (±0.013) and an error weighted mean of 0.138 (±0.001). These ratios are lower than a previously reported ratio for Sydney, and lower than the global average. However, these ratios are similar to those reported for other sites within Australia that are located away from former weapons testing sites and indicate that atom ratio measurements from other parts of the world are unlikely to be applicable to the Australian context. PMID:26344369

  4. Estimation of the parameters of 137Cs and 90Sr excretion from small rodents' organism by a non-radiochemical methods

    Parameters of 90Sr and 137Cs excretion were assessed for 13 individuals of bank vole Clethrionomys glareolus, which were caught on one of the central plots of the Chornobyl zone, and were placed to lab conditions on 'clean' food. In the result of the 2-month experiment it has been found out that decontamination of voles' organism from 90Sr is described by one-compartment equation of exponential decay with decrease half-life of 77,3 d; 137Cs one - by two-compartments equation with half-life periods of 1,87 d (95%) and 55,2 d (5%)

  5. Radionuclides 137Cs and 90Sr accumulation in perennial feed grasses yield at potash fertilizers application on peat soil

    In research in 2004-2006 conditions of moistening have had favorable influence on productivity of grasses, but more damp conditions in 2006 promoted to radionuclides accumulation by grasses. The correlation analysis of data of three year research has shown the presence of weak direct correlation communication between values of coefficient of proportionality (CP) 137Cs and the conventional index of providing with moisture GTK (?=0.23), CP 90Sr and GTK (?=0.19). Weather-climatic conditions of the vegetative period have rendered more significant influence on the level of productivity. The correlation factor between size of productivity and values of GTK has made 0.63. The presence of negative correlation communication between values CP137Cs and size of productivity (r =-0.49), CP 90Sr and size of poductivity (? =-0.48) is established. For years of research there was an increase in the content of mobile potassium in peat soil in variants with to one-component potassium application, phosphorus and potash combinations and full mineral fertilizer up to 540-1020 mg/kg soil. The presence of close negative correlation communication of values of CP 137Cs and content of mobile potassium in soil (? =-0.76), CP 90Sr and content of mobile potassium in soil (? =-0.74) is established

  6. Prediction of accumulation of 137Cs by plants based on the kinetic model of radionuclide behaviour in the system soil-plant

    To predict accumulation of 137Cs by plants information of the long-term radio-ecological monitoring of contaminated lands of Ukraine was utilized (about 3500 pairs soil-plant). Based on modern views about transformation of radionuclide forms in soil the kinetic model of 137Cs behaviour in the system soil-plants was created. As an argument, it uses the integrated assessment of soil properties calculated with a triad-reaction of soil solution, humus content and sum of absorbed grounds. Program to predict concentration of '137Cs in plants is developed and a user guide is created.

  7. Yield of wheat varieties and removal of radionuclide 137Cs on land contaminated with radionuclides

    Data on yielding capacity of wheat (Triticum aestivum) winter and spring varieties, specific activity of Cs137 radionuclide in grain and straw, total removal of Cs137radionuclide and potassium were presented analysed in the conditions of the Republic of Belarus. The tested wheat varieties were evaluated from point of view of individual and collective doses reduction in case of cultivation for food on land contaminated with radionuclide Cs137. Selection of varieties of agricultural crops with the minimum doses of radionuclide accumulation proved to an efficient and low-cost action which reduced the transit of radionuclides ino production. From the point of view of minimization of collective doses of internal irradiation of population in case of recommendation of a variety for cultivation in a zone with radioactive contamination along with the minimum doses of specific radionuclide activity it was necessary to consider its total removal from area unit. As a result of a complex evaluation of recognized and perspective varieties of cereals - winter and spring wheat – in the conditions of their cultivation on polluted with 137 radionuclide territories for minimization of individual and collective doses of an internal irradiation of population it was established, that the greatest decrease in an individual dose was provided with a variety of winter wheat Tsentos and a variety of spring wheat Kvattro, characterized by the least specific activity of Cs137 in grain and straw, which was on 1,8 and 1,3 times lower than the corresponding standards. There was weak relationship between carrying out Cs137 and potassium in winter and spring wheat varieties

  8. Migration of 137Cs artificial radionuclide in the valley of the Takhtakushuk river of the Degelen massif

    Study of horizontal and vertical radionuclide distribution in the valley of the Takhtakushuk River of the 'Degelen' Massif is carried out in the framework of ecological and biological investigations of soil and plant cover within radioactive contaminated areas, and radionuclide migration in biological chain 'soil - plant - animal'. For the first time, the pool-type method was used in the studies of soil of the valley that allows tracing solid and liquid substances migrating by means of surface and soil drainage from its head to final part. This paper presents some physical and chemical properties of the study landscape's soils, radionuclide content in soil genetic horizons of the valley. The study results showed that major mass of 137Cs radionuclide is sorbed by soil humus and fine-dispersed clay particles of grass soils within the valley. (author)

  9. Deposition of 7Be and 137Cs in Sweden 2001 - 2008. With Radionuclides in ground level air in Sweden. Yearly report 2008

    Deposition of 7Be and 137Cs for four stations in Sweden are reported for the period 2001- 2008. For 7Be a correlation with total precipitation is seen. For 137Cs there is no correlation with precipitation and no correlation with surface air concentrations of 137Cs. The overall levels of 137Cs fallout is higher in areas that were largely affected by the Chernobyl fallout in 1986. The 137Cs deposition seen in the Gaevle area are mostly due to resuspension of this 137Cs fallout, but for other areas the total yearly deposition and resuspension are down to pre Chernobyl levels. Filtering of ground level air is performed continuously at six different locations in Sweden: Kiruna, Umeaa, Gaevle, Kista, Visby and Ljungbyhed. The filters are pressed into weekly samples and the contents of different radionuclides are measured by gamma spectroscopy. Precipitation is also collected at four of the stations: Kiruna, Gaevle, Kista and Ljungbyhed, the samples are ashed and the contents of radionuclides are measured. The levels of Be-7 and Cs-137 during 2008 in air and precipitation are presented for the different stations. Other anthropogenic radionuclides detected, if any, are also presented

  10. Field measurements of environmental radionuclides 137Cs and 210Pbex inventories using in-situ gamma-ray spectrometry

    In-situ measurement of environmental radionuclides 137Cs and 210Pbex has a potential to assess soil erosion and sedimentation rapidly. In this study, we measured the inventories of 137Cs and 210Pbex in the soil of Inner Mongolia grassland using an in-situ gamma detector with the 50 mm shield and Collimator mounted on a cart (ISOCS, In-situ Object Counting System). The detector was set up one meter above the ground with 90 degree collimator installed: the counting time is more than 3600s. The field survey data were compared with data from laboratory analysis of section cores. The results showed that the mean deviations of measured values between field and laboratory measurements are less than 8%, indicating a high precision for in-situ gamma spectrometry. The inventories of 210Pbex measured by in-situ γ spectrometry were much higher than the laboratory measurements due to a short measurement time in the field. The results from our pilot study indicated that in-situ gamma-ray spectrometry has the following advantages over traditional laboratory measurements: no time consuming sample collection, prompt availability of the results, averaging radionuclide activity over a large area and high precision. (authors)

  11. Leaves of higher plants as biomonitors of radionuclides (137Cs, 40K, 210Pb and 7Be) in urban air.

    Todorović, Dragana; Popović, Dragana; Ajtić, Jelena; Nikolić, Jelena

    2013-01-01

    Leaves of linden (Tilia tomentosa L. and Tilia cordata Mill.) and horse chestnut (Aesculus hippocastanum L.) were analysed as biomonitors of radionuclides in urban air. Samples of soils, leaves and aerosols were collected in Belgrade, Serbia. Activities of (137)Cs, (40)K, (210)Pb and (7)Be in the samples were measured on an HPGe detector by standard gamma spectrometry. "Soil-to-leaves" transfer factors were calculated. Student's t test and linear Pearson correlation coefficients were used for statistical analysis. Differences in local conditions at the sampling sites were not significant, and the mechanisms of the radionuclides' accumulation in both plant species are similar. Ceasium-137 was detected in some of the leaf samples only. Transfer factors for (137)Cs and (40)K were (0.03-0.08) and 1.3, respectively. The concentrations of (210)Pb and (7)Be in leaves were higher in autumn than in spring, and there were some similarities in their seasonal patterns in leaves and in air. Weak to medium correlation was obtained for the (210)Pb and (7)Be activities in leaves and aerosols. Large positive correlation was obtained for the (210)Pb activities in linden leaves and the mean activity in aerosols for the preceding months. Different primary modes of radionuclides accumulation in leaves were observed. Since large positive correlation was obtained for the (210)Pb activity in linden leaves and the mean in aerosols for the preceding months, mature linden leaves could be used as biomonitors of recent (210)Pb activity in air. PMID:22562351

  12. Natural radionuclides and {sup 137}Cs in commercialized edible mushrooms in Sao Paulo-Brazil; Radionuclideos naturais e {sup 137}Cs em cogumelos comestiveis comercializados em Sao Paulo - Brasil

    Castro, Lilian Pavanelli de

    2008-07-01

    Artificial and natural radionuclides are commonly found in several compartments of the earth's crust. Some mushroom species have a high capacity to absorb radionuclides and toxic elements from the soil. Diet is considered as one of the main routes of radioactive contamination. Therefore, radioactivity measurements in the environment and in food are extremely important to monitor the radiation levels that human can be exposed to either directly or indirectly. Environmental bio monitoring has demonstrated that diverse organisms such as crustaceans, fish and mushrooms are useful when evaluating both the contamination and the quality of the ecosystems. There are actually several radionuclides that can be accumulated in mushrooms, including {sup 40}K, {sup 137}Cs, {sup 232}Th and {sup 238}U. There are few studies in the Southern hemisphere countries, on the natural and artificial radioactivity levels in mushrooms. The present study evaluated {sup 40}K, {sup 137}Cs, {sup 232}Th and {sup 238}U in commercialized edible mushrooms in the state of Sao Paulo, Brazil. The edible mushroom samples were acquired in different commercial establishments in the Sao Paulo metropolitan region, specifically in Municipal Markets. Some samples were acquired directly from producers located in the cities of Mogi das Cruzes, Mirandopolis, Suzano and Juquitiba. About 400g were collected for each edible mushroom species, which included Agaricus sp, Pleurotus sp and Lentinula sp species. All the samples were prepared and stored in polyethylene bottles for approximately 35 days, so that secular equilibrium could be established before counting. The {sup 40}K, {sup 137}Cs, {sup 232}Th and {sup 238}U gamma activities were measured by gamma spectrometry. The equipment consisted of a Hyper pure Germanium detector connected to an electronic system. The detector efficiency was obtained from measurements of reference materials: IAEA-300, IAEA-327 and IAEA-375. The results for the specific activities

  13. Behaviors and transfers of anthropogenic radionuclides (137Cs, 239+240Pu and 241Am) in a protected alpine wetland (France)

    The aim of this study is to confirm and increase the knowledge on anthropogenic radionuclide (RN) behavior (137Cs, 239+240Pu, 241Am) in natural compartments (artificial pool in a protected upland area). The novelty lies on comparisons of the three main compartments (pool water, soil, sediments) of this original mountainous site. Migration processes and transfers were particularly detailed in the light of two processes: lixiviation and leaching. Regarding 238U, anthropogenic RNs, lithology, organic matter contents, sedimentation rates (210Pb) and isotopic mass balances, RNs are mainly transported by leaching processes with higher 241Am in-depth mobility compared to 137Cs (intermediate for 239+240Pu). (author)

  14. Soil to leaf transfer factor for the radionuclides 226Ra, 40K, 137Cs and 90Sr at Kaiga region, India

    Transfer factors are the most important parameters required for mathematical modeling used for environmental impact assessment of radioactive contamination in the environment. In this paper soil to leaf transfer factor for the radionuclides 40K, 226Ra, 137Cs and 90Sr is estimated for Kaiga region in Karnataka state, India. Among the plants in which study is carried out, 226Ra, 40K, 137Cs and 90Sr activity in leaves of herbaceous plants is higher than that of tree leaves. Soil to leaf transfer factor for 226Ra, 40K, 137Cs and 90Sr was found to be in the range of 0.03-0.65, 0.32-8.04, 0.05-3.03 and 0.42-2.67 respectively. - Highlights: → Study region is Kaiga, Karnataka, India. → 226Ra, 40K, 137Cs and 90Sr activity in soil and leaf samples are reported. → 226Ra, 40K, 137Cs activity is higher in herbaceous plant leaves, than tree leaves. → In most of the plants transfer factor varies in the order K > Sr > Cs > Ra.

  15. Radionuclides (210Pb, 226Ra, 210Po e 137Cs) in the Cananeia-Iguape coastal system: environmental studies

    This work was developed in the Cananeia-lguape Coastal System, coast south of the State of Sao Paulo, with the aim of monitoring the levels of some natural radionuclides (210Pb, 210Po, 226Ra ) and artificial (137Cs) and to study the sedimentary dynamics of the area. For this, some studies and determinations were carried out, such as: sedimentation rates, concentration factors, bio-indicators and ingestion for the human population of some of these radionuclides. For the obtaining of the levels of these radionuclides, radiochemical and instrumental methodologies were developed and applied in reference samples of the International Agency of Atomic Energy (IAEA). After this, the methodologies were applied in samples of sediments, aquatic organisms and water of the channels collected in several points. In the sediments, the levels of (210Pb, 226Ra and 137Cs varied from 6.1 to 167.5 Bq.kg-1 from 4.1 to 28.5 Bq.kg-1 and from MDC (0.28) to 6.1 Bq.kg-1 respectively. More significant correlations were observed among the percentage of mud (silt-clay) in the sediments and the levels of these radionuclides. These data were used for sedimentation rate studies in the points of sampling in the System. The sedimentation rates obtained with the values of unsupported (210Pb and 137Cs for the Ponta do Arrozal (T1), Ponta do Frade (T2), Valo Grande (T3) and Carapara-BOCA River (T4) were of 5.02 and 5.00 mm.a-1, 2.30 and 3.82 mm.a-1, 14.59 and 15.74 mm.a-1, 3.41 and 5.00 mm.a-1 respectively. The sedimentation rates obtained with unsupported 210Pb and the 137Cs in the cores(T1, T2, T3 and T4) showed a good agreement. The sedimentation rates obtained along the System reflect the dynamics intern of the channels, that presents general tendency the one accentuated deposition process, with pronounced contribution of sediments of continental origin, for the drainages Mandira and Ribeira of Iguape Rivers, by the high biological production of the System as well as the pronounced erosion of the

  16. Accumulation and excretion of radionuclides by alga Chara tomentosa

    It has been found in the course of the study of accumulation and excretion of radionuclides by alga chara tomentosa that 55Fe, 60Co, 91Y are accumulated by living and dead components of alga chara tomentosa to a far greater extent and are stronger retained than 90Sr, 137Cs, 144Ce. The main part of the absorbed quantities of all investigated nuclides (80-92%) is fixed on the surface of the plant in the ''cortex'' layer

  17. 3D modeling technique of time-series 137Cs concentration in coastal organisms in case of short term introduction

    Short term estimation of released radionuclides behavior is necessary for decision-making in emergent action. To predict radionuclide concentrations in marine organisms under short term radionuclide introduction to coastal water, the simple time series 137Cs transfer both from seawater and food chain to marine organisms were studied. The model was developed for typical Japanese coastal water including benthic food chain and planktonic food chain, with transfer parameter data set, such as uptake rate constant, excretion rate constants, gut transfer rates, food ingestion rates of 137Cs, those collected by many tracer experiment studies. For the development of the modeling technique in prediction of the temporal 137Cs concentrations in marine biota, the time and space distributions of 137Cs concentrations in marine organisms are important especially in case of short term introduction to coastal area. We developed a 3-dimension model being composed of nuclide transfer both from seawater and food chain in imaginary coastal area, expressing the temporal 137Cs concentrations in marine organisms accompanied with the habitat location. The result of 3D modeling in case of short term introduction to exhibit the following information: 1) The introduced 137Cs in seawater is diluted and disappeared quickly under normal current conditions, while 137Cs in organisms slowly increased even after the seawater is cleared, mainly from the contribution from 137Cs transfer through food chain. 2) The 137Cs concentration in fish of higher trophic level appears approximately 100 days later, and the concentration ratio (137Cs in organism/137Cs in seawater) reaches only 1-10 even using the maximum 137Cs concentrations in organism and seawater

  18. The fate of long-lived radionuclides 137Cs and 90Sr in the Black Sea after Chernobyl NPP accident: role of hydrophysical factors and tracer applications

    -50 m layer being depleted annually, and radioactive decay. In the case of 90Sr, these processes have been compensated essentially by river inputs from the Dnieper and Danube Rivers. The outflows from the Black Sea to the Mediterranean are interesting for estimating of radionuclides budgets in the Mediterranean Sea and for better quantifying the Chernobyl signal. The ratio 134Cs/137Cs in surface water with a decay corrected value of 0.53 ± 0.1 at 1 May 1986, showed clearly that radiocaesium had Chernobyl origin. This ratio proved to be a very useful tool for identifying Chernobyl derived 137Cs, which can be used for estimation of physical mixing processes in the Black Sea. During the subsequent years Chernobyl derived 137Cs distributed relatively rapid into the permanent Black Sea pycnocline. Further development of this approach had shown that in the Central Black Sea Basin about 50 % content of the surface water in the low permanent Black Sea pycnocline reached during 3-5 years. Consequently, total ventilation time of low permanent Black Sea pycnocline by surface waters can be estimated as 15-25 years. The process of vertical 137Cs and 90Sr transfer has been observed mainly in the 0-200 m layer of the Black Sea. Temporary evolution of 137Cs and 90Sr profiles in the Black Sea Deep-Water Basin was used for further estimations of a large-scale vertical water mixing. All 137Cs and 90Sr profiles included three parts: the high-concentrations surface mixed layer, the gradient layer and the low-concentrations layer underneath. After 1986 the increase in the surface mixed layer's thickness up to the upper boundary of the halocline and the sinking of the gradient layer for 137Cs and 90Sr profiles have been observed. The downward velocity of the gradient layer was used as an indicator of the vertical water mixing intensity. 137Cs and 90Sr profiles have been modelled by sigmoid functions with following differential analysis. The results shown that in the course of the first year

  19. Mesoscale variability of vertical profiles of environmental radionuclides (40K, 226Ra, 210Pb and 137Cs) in temperate forest soils in Germany

    Vertical profiles of environmental radionuclides (40K, 226Ra, 210Pb and 137Cs) were investigated in several temperate forest soils in Germany to estimate heterogeneity of the soil horizon of interest. Absolute values of the activity concentrations of these nuclides varied to a large extent depending on the properties of individual forests as well as local geology. Several trends were generally observed independent of the location: (1) Activity concentrations of 40K increased with increasing soil density reflecting that most potassium is contained in mineral components of the soil. The variations in the 40K activity with depth may relate to biological activities in subsoil, such as root uptake of the nutrients. (2) Profiles of 226Ra with depth could be an indicator for evaluating soil heterogeneity within a horizon of interest. They are also useful to estimate anthropogenic 210Pb (210Pbexc) derived from the atmosphere via dry fallout or wet deposition. In several forests, there appeared surface enrichment of 210Pb down to a depth of approximately 10 cm, in which the 210Pb would have come from the atmosphere by combustion of fossil fuels. (3) Depth profiles of 137Cs were roughly divided into three types in which (a) the activity concentration decreased exponentially with soil depth, (b) small amounts of 137Cs existed only in the upper-most layer of the soil (0-5 cm) and (c) 137Cs disappeared at certain depths and appeared again at deeper portions of the soil. Consequences of bioturbation could be deduced from variability in vertical profiles of the environmental radionuclides. It is probable that a site showing an exponential decrease of the 137Cs activity with depth and also having a surface enrichment of 210Pb is not significantly influenced by bioturbation

  20. A thermodynamic study of decontamination of soils contaminated with 137Cs radionuclide as the results of accident at Chernobyl NPP

    Thermodynamic characteristics of the process of soil decontamination from 137Cs by the their washing with eluting solution, Fe(3) and ammonium being included in its composition, have been determined. The decontamination process is 137Cs desorption as a result of destruction of cesium chelate complexes with humic acids. Fe3+ and Fe(OH)2+ substitution for Cs+ in the soils occurs spontaneously as a thermodynamically efficient process. 3 refs.; 1 fig

  1. Geoinformational modelling of the land use of Polesye and Opolje landscapes in Bryansk region (Russia) under conditions of 137Cs radionuclides contamination

    Nenko, Christina; Linnik, Vitaliy; Volkova, Nadezhda

    2015-04-01

    Significant part of Russian Federation was contaminated by 137Cs radionuclides due to Chernobyl disaster in 1986. South-western part of Bryansk region has suffered the most. Study area (the central part of Bryansk region, Polesye and high plains landscapes) is situated outside the officially specified zone of contamination with contamination levels under 1 Ci / km2. Nevertheless, such contamination levels (which are 20 times greater than levels of global fallout) require particular attention as it may contain a threat of the land use and the health of population, living within the territory. Radioactive contamination within the model area was formed as a result of a "dry" deposition from the atmosphere. Consequently, the initial contamination of soil by isotopes 137Cs, unlike the western part of the Bryansk region, was spread relatively equally. The main part of 137Cs (up to 90%) in natural landscapes is contained in the top 5 cm of soil, which itself creates danger of biogeochemical migration from soil to plants. In agricultural landscapes under cultivation 137Cs is uniformly spread within a 20 cm layer of soil and can also come from soil to plants grown in the fields. The area of radioactive contamination that was formed during the period of deposition (late April - early May 1986), is exposed to the processes of secondary redistribution. It is influenced by several factors as topography, vegetation type, proportion of arable soils, soil humidity, soil texture etc. In the presented study there was evaluated the impact of these factors on the secondary redistribution of 137Cs. Sustainable development of agricultural production in the contaminated territories requires managing a number of measures to reduce radiation risks to the population. Regarding this point the greatest threat may be represented by milk production, as well as picking berries and mushrooms. Planning of the sustainable use of the territory requires an evaluation of contamination levels within

  2. Bioaccumulation of 137Cs by microorganisms isolated from soils contaminated with radionuclides

    With the aim to evaluate the possibility of utilisation of autochtone population of soil organisms, alone or with participation of higher plants, in the processes of bioremediation the authors quantitatively determined a number of psychrophyllic and mezophyllic germs in the soils contaminated by low-level activities of Cs-137 (0.08 - 2.8 kBq/g). Hereafter they gained isolates of clean cultures of mushrooms and actinomycetes and they determined their bioacumulative activity of Cs-137 at growing conditions. The authors found out, that a number of reproductionable psychrophyllic and mezophyllic germs are significantly lower in the soils with the highest contamination by radionuclides than in the soils with low contamination. They gained the clean cultures of 5 isolates of micromycetes and 3 isolates of actinomycetes from contaminated soil. The micromycetes demonstrated the highest values of bioaccumulation of caesium 39 nmol/g of wet biomass at the growing conditions. In actionoomycetes these values were 4.7 nmol/g (approximately in one order lower). The significant part of cesium accumulated by cell matter at growing conditions were localised in cell matter and it could not be removed by washing with 0.9 percent of NaCl solution. The determined values of bioconcentration factor BCF recalculated on dry weight of biomass were in the range from 16.04 to 26.20 in micromycetes and 3.24 in actinomycetes. From this situation arise, that autochtone population of soil micromycetes and actionomycetes, which is found in contaminated soil, can relevantly participate in the processes of binding of biologically accessible forms of Cs-137 after a creation of suitable conditions for grow. (author)

  3. Evaluation of small scale laboratory and pot experiments to determine realistic transfer factors for the radionuclides 90Sr, 137Cs, 60Co and 54Mn

    Transfer factors for the root uptake of 90Sr, 137Cs, 60Co and 54Mn were compared using outdoor lysimeters, Kick-Brauckmann experimental pots under greenhouse conditions and Neubauer cups under growth chamber conditions. The uptake was studied in barley, potatoes, sugar beet and salad vegetables grown on either podsolic or loess soil. The transfer factors for these radionuclides under the specific conditions of the small scale Neubauer cup experiments differed greatly from those obtained from the outdoor lysimeter. In the pot experiments, the transfer factors for 90Sr, 137Cs and 54Mn showed less deviation from the lysimeter results especially in crops grown on podsolic soil. For 60Co, the transfer factors varied for the different crops grown. Transfer factors obtained in pot experiments can only be applicable to a limited extent to field conditions; factors influencing the transfer factors in pot experiments include soil volume, root density, root/shoot ratio, water supply and fertilizer application rate. (UK)

  4. Desorption of 137Cs+ from mosses

    OLGICA NEDIC

    2002-09-01

    Full Text Available Mosses are biomonitors that accumulate large amounts of various pollutants, including radionuclides. In this work we investigated the possibility of 137Cs extraction from mosses, as well as the significance of species specificity on the efficiency of 137Cs desorption. Salt and acid solutions were used as extraction media. It was shown that a 5 % solution of both ammonium oxalate and phosphoric acid was able to desorb 81.8 % of 137Cs+ from Homalothecium sericeum, which was 39.9 % more than desorption from water. At the same time, most of the desorbed 137Cs+ was incorporated in crystals that precipitated from the solution. An interspecies difference in respect to 137Cs+ desorption was noticed.

  5. Atmospheric deposition of radionuclides (7Be, 210Pb, 134Cs, 137Cs, and 40K) during 2000-2012 at Rokkasho, Japan, and impact of the Fukushima Dai-ichi Nuclear Power Plant accident

    Radionuclides, including radiocesium (134Cs and 137Cs), were measured in atmospheric deposition samples collected in Rokkasho, Aomori, Japan, from 2000 to 2012. After the accident at the Fukushima Dai-ichi Nuclear Power Plant, radiocesium deposition rapidly increased and reached a maximum in April 2011. Since then, monthly radiocesium deposition has gradually decreased. Monthly 137Cs deposition has almost reached pre-accident levels, although 134Cs is still being detected. (author)

  6. Effects of arctic temperatures on distribution and retention of the nuclear waste radionuclides 241Am, 57Co, and 137Cs in the bioindicator bivalve Macoma balthica

    Hutchins, D.A.; Stupakoff, I.; Hook, S.; Luoma, S.N.; Fisher, N.S.

    1998-01-01

    The disposal of radioactive wastes in Arctic seas has made it important to understand the processes affecting the accumulation of radionuclides in food webs in coldwater ecosystems. We examined the effects of temperature on radionuclide assimilation and retention by the bioindicator bivalve Macoma balthica using three representative nuclear waste components, 241Am, 57Co, and 137Cs. Experiments were designed to determine the kinetics of processes that control uptake from food and water, as well as kinetic constants of loss. 137Cs was not accumulated in soft tissue from water during short exposures, and was rapidly lost from shell with no thermal dependence. No effects of temperature on 57Co assimilation or retention from food were observed. The only substantial effect of polar temperatures was that on the assimilation efficiency of 241Am from food, where 10% was assimilated at 2??C and 26% at 12??C. For all three radionuclides, body distributions were correlated with source, with most radioactivity obtained from water found in the shell and food in the soft tissues. These results suggest that in general Arctic conditions had relatively small effects on the biological processes which influence the bioaccumulation of radioactive wastes, and bivalve concentration factors may not be appreciably different between polar and temperate waters.

  7. Preliminary Study on the Use of Radionuclides 137Cs and 210Pb and Spectro radiometry Techniques as Tools to Determine Soil Erosion State

    Radionuclides are largely used as tools for studying and quantifying soil erosion. The global fallout of artificial radionuclides derived from weapons testing (1945-1970) was rapidly and firmly fixed in soil surface horizons. This allowed determining soil erosion by comparing 137Cs inventories at individual sampling points with a reference inventory. This procedure is complemented with the 210Pbuns inventory calculation as an indicator of the local average of radionuclides deposition. Spectro radiometry is implemented to associate soil reflectance measurements to physical and chemical soil properties related to soil erosion processes obtained from laboratory analyses. The methodology applies both instrumental techniques in soil samples from a semiarid agricultural area near to Camarena (Toledo). The resulting inventories obtained for 137Cs and 210Pbexc are similar to the Spanish reference allowing comparation. Spectro radiometry results correlate well with soil properties measured in the laboratory and can be applied to determine these properties more quickly and easily, as well as for integration with gamma spectrometry results. This is a preliminary study to identify soils affected by erosion that is presented as a Master thesis of the Official Master Degree: Agro- Environmental Technology for a Sustainable Agriculture, of the Technical University of Madrid - School of Agricultural Engineers (UPM-ETSI). Coherent and complimentary results are obtained applying both instrumental techniques within this agricultural area.. (Author)

  8. 137Cs concentration in stingray (Dasyatis akajei)

    137Cs, which is of great interest and importance as an indicator of radioactive pollution in marine environments, is one of the long-lived artificial radio-nuclides introduced by the atmospheric deposition of debris from nuclear explosions mainly before 1962. For the estimation of effects of the effluents from nuclear facilities, it is necessary to know the natural variations in the concentration of 137Cs and factors affecting variations in marine organisms. We observed positive correlation between growth and 137Cs in 4 species among 14 major teleost species from fishing grounds along the coast of Japan. No increase in 137Cs concentration with increase of growth was observed in 2 species. In the remaining species no specific correlation is observed. These differences in the patterns were dependent on a change of feed habits with growth. As little is known of the 137Cs concentration in selachian we have investigated the natural variations of 137Cs in stingray. The correlation between growth and the concentration of 137Cs in stingray will be discussed. (author)

  9. Interaction matrices as a first step toward a general model of radionuclide cycling. Application to the 137Cs behavior in a grassland ecosystem

    Interaction matrices, an expert semi quantitative method to identify multiple interactions among biotic and abiotic components of the ecosystem can be considered as a useful tool to develop conceptual models of the behavior of radionuclides in the environment. This systematic approach facilitates a comprehensible identification of the pathways of the main radionuclides and permits classification of the role of different ecosystem components in terms of cause-effect relationships. The method was applied to study the radiocesium migration in grassland ecosystem affected by the Chernobyl 137Cs deposition. Interaction matrices have been simultaneously utilized to explore the dynamic changes on the radiocesium migration pathways and to compare the consequences of the various radiation exposure paths to living organisms. (author)

  10. Radiochemical determination of 137Cs in foods

    A determination of radionuclides in food samples is important in commodities in order to attend to regulatory requirements for international trade. As a long-lived radioisotope of cesium, 137Cs is produced as a result of human nuclear activities and than its contamination level evaluation among others radionuclides in foods is necessary. A methodology for the determination of 137Cs in foods, pork and fish, is described. The procedures covered homogenization and freeze-drying of the samples. The 137Cs was measured by gamma spectrometry using Canberra 50% HPGe detector. The counting was carried out with Monte Carlo software for detection conditions optimization including geometry and chemical data information. A certified sample, SRM IAEA-375, was analyzed in order to evaluate the reliability of the method, and the results showed good agreement between the measured and certified values. (author)

  11. {sup 137}Cs, {sup 90}Sr, {sup 241}Am and {sup 239+240}Pu radionuclides speciation in soils of the former Semipalatinsk test site

    Kabdyrakova, A.M.; Kunduzbaeva, A.Y.; Lukashenko, S.N.; Magasheva, R.Y. [Institute of radiation safety and ecology (Kazakhstan)

    2014-07-01

    The paper presents results of studies into {sup 137}Cs and {sup 90}Sr, {sup 241}Am and {sup 239+240}Pu techno-genic radionuclides speciation in soils of ecosystems at different topography of the Semipalatinsk Test Site (STS), exposed to different nuclear testing. The data were obtained for radionuclides speciation in soils of the following STS ecosystems: - grassland ecosystems within near-portal areas of tunnels - horizontal adits constructed for nuclear testing, affected by radioactive-contaminated water flows from the tunnels of Degelen Site; - steppe ecosystems, exposed to ground radioactive contamination resulted from above-ground and aerial nuclear testing of different yield, as well as simulation (hydrodynamic and hydro-nuclear) experiments at 'Experimental Field' testing site. - steppe ecosystems, exposed to ground radioactive contamination caused by testing of liquid and powdery radiological warfare weapon (RWW) at Site '4 a'; - 'Northern' and 'Western' areas of STS, where concentration level of artificial radionuclides in soil is comparable with the level of global fall-outs ('background' areas). To study the radionuclides speciation, method of sequential extraction was applied, and water-soluble, exchange, organic mobile and tightly bound forms were separated. Feature of the studied grassland ecosystems is that they are developed solely along the bed of water streams flowing from tunnels and are located at small area of 1-2 m{sup 2}. Radioactive contamination of soil is caused by radioactive contaminant sorption by sediments. Despite the significant space limitation of the ecosystems content of radionuclides speciation in soil greatly varies, particularly readily-soluble and mobile forms. The variation may be explained by high humidity which makes possible both sorption and desorption processes. If basic radionuclides contributing to radioactive contamination of grassland soils at Degelen Site are {sup

  12. 137Cs, 90Sr, 241Am and 239+240Pu radionuclides speciation in soils of the former Semipalatinsk test site

    The paper presents results of studies into 137Cs and 90Sr, 241Am and 239+240Pu techno-genic radionuclides speciation in soils of ecosystems at different topography of the Semipalatinsk Test Site (STS), exposed to different nuclear testing. The data were obtained for radionuclides speciation in soils of the following STS ecosystems: - grassland ecosystems within near-portal areas of tunnels - horizontal adits constructed for nuclear testing, affected by radioactive-contaminated water flows from the tunnels of Degelen Site; - steppe ecosystems, exposed to ground radioactive contamination resulted from above-ground and aerial nuclear testing of different yield, as well as simulation (hydrodynamic and hydro-nuclear) experiments at 'Experimental Field' testing site. - steppe ecosystems, exposed to ground radioactive contamination caused by testing of liquid and powdery radiological warfare weapon (RWW) at Site '4 a'; - 'Northern' and 'Western' areas of STS, where concentration level of artificial radionuclides in soil is comparable with the level of global fall-outs ('background' areas). To study the radionuclides speciation, method of sequential extraction was applied, and water-soluble, exchange, organic mobile and tightly bound forms were separated. Feature of the studied grassland ecosystems is that they are developed solely along the bed of water streams flowing from tunnels and are located at small area of 1-2 m2. Radioactive contamination of soil is caused by radioactive contaminant sorption by sediments. Despite the significant space limitation of the ecosystems content of radionuclides speciation in soil greatly varies, particularly readily-soluble and mobile forms. The variation may be explained by high humidity which makes possible both sorption and desorption processes. If basic radionuclides contributing to radioactive contamination of grassland soils at Degelen Site are 137Cs and 90Sr, then at Experimental Field site these are transuranic radionuclides

  13. Transfer of some artificial (226Sr and 137Cs) and natural (40K and 226Ra) radionuclides from milk to its products

    Transfer of some artificial radionuclides ( 137 Cs and 85 Sr) and natural radionuclides (226 Ra and 40K) from milk (cheep and cows) to its products processed according to local manufacturing procedures (home made cheese, kashkawan cheese, shelal cheese, haloom cheese, kareshah cheese, sharkasiah cheese, liquid cheese, yogurt, butter and keshdah) has been studied. The results showed that the retention percent of radium 226 in milk products has reached %100 in the home made cheese and %72 for strontium 85 in the shelal cheese and %40 for cesium 137 in yogurt and %46 for potassium 40 also in yogurt. In addition, most of the retention percent ratios of the studied radionuclides in yogurt were relatively low (about %25 and % 40 in the yogurt processed from the milk of the cows and cheep respectively) with a high processing efficiency, so that making yogurt from the contaminated milk is the best way to reduce the contamination ratio and to make use of the contaminated milk. Furthermore, home made cheese was processed with salty solutions of different concentrations and the results showed that about %90 of cesium and potassium has transferred to the salty solution of %5 soaked for 48 hours, while %40 of the radium and %80 of strontium were removed from the contaminated cheese after 48 hours soaking in a salty solution of %2.5. However, the results of the present work can be used for processing of contaminated milk with artificial radionuclides in order to be utilized. (Authors)

  14. Atmospheric deposition of radionuclides (7Be, 210Pb, 134Cs, 137Cs and 40K) during 2000-2012 at Rokkasho, Japan, and impact of the Fukushima Dai-ichi Nuclear Power Plant accident

    We measured the concentrations of several radionuclides in atmospheric deposition samples collected in the period from 2000 to 2012 at Rokkasho, Japan. Monthly 7Be deposition rates were higher in winter/spring and fall, and monthly 210Pb deposition rates were highest in winter/spring. Following the accident at the Fukushima Dai-ichi Nuclear Power Plant in March 2011, the radiocesium (134Cs and 137Cs) deposition rate rapidly increased until it reached the maximum in April 2011, after which the deposition rate of 137Cs decreased with a half-time of 22 days before remaining constant throughout 2012. (author)

  15. Putative bioindicator of 137Cs in Perna viridis

    Green lipid mussels (Perna viridis L.) are utilized as bioindicators and bioconcentrators not only for marine radionuclide contamination but also for heavy metal bioaccumulation. Depurated P. viridis were incubated in 137Cs-spiked aquarium for 4 days. Soluble protein fractions of soft tissue obtained were electrophoresed (SDS-PAGE) to determine the exposure effects of 137Cs on P. viridis. Results showed the presence of a 154-kDa protein in 137Cs-spiked samples which could be a potential bioindicator of 137Cs in P. viridis. Other differences involving two more proteins (∼94-kDa and∼61 KDa) are reported. (Author)

  16. Atmospheric removal times of the aerosol-bound radionuclides 137Cs and 131I measured after the Fukushima Dai-ichi nuclear accident – a constraint for air quality and climate models

    G. Wotawa

    2012-11-01

    Full Text Available Caesium-137 (137Cs and iodine-131 (131I are radionuclides of particular concern during nuclear accidents, because they are emitted in large amounts and are of significant health impact. 137Cs and 131I attach to the ambient accumulation-mode (AM aerosols and share their fate as the aerosols are removed from the atmosphere by scavenging within clouds, precipitation and dry deposition. Here, we estimate their removal times from the atmosphere using a unique high-precision global measurement data set collected over several months after the accident at the Fukushima Dai-ichi nuclear power plant in March 2011. The noble gas xenon-133 (133Xe, also released during the accident, served as a passive tracer of air mass transport for determining the removal times of 137Cs and 131I via the decrease in the measured ratios 137Cs/133Xe and 131I/133Xe over time. After correction for radioactive decay, the 137Cs/133Xe ratios reflect the removal of aerosols by wet and dry deposition, whereas the 131I/133Xe ratios are also influenced by aerosol production from gaseous 131I. We find removal times for 137Cs of 10.0–13.9 days and for 131I of 17.1–24.2 days during April and May 2011. The removal time of 131I is longer due to the aerosol production from gaseous 131I, thus the removal time for 137Cs serves as a better estimate for aerosol lifetime. The removal time of 131I is of interest for semi-volatile species. We discuss possible caveats (e.g. late emissions, resuspension that can affect the results, and compare the 137Cs removal times with observation-based and modeled aerosol lifetimes. Our 137Cs removal time of 10.0–13.9 days should be representative of a "background" AM aerosol well mixed in the extratropical Northern Hemisphere troposphere. It is expected that the lifetime of this vertically mixed background aerosol is longer than the lifetime of fresh AM aerosols directly emitted from surface sources. However, the substantial difference to the mean

  17. Mass accumulation rates and fallout radionuclides 210Pb, 137Cs and 241Am inventories determined in radiometrically dated abyssal sediments of the Black Sea

    Five abyssal (deep-sea) sediment cores collected during the two international cruises on R/V 'Professor Vodyanitskiy' (RADEUX-1998 and RADEUX-2000) in the framework of the Regional Technical Co-operation Project RER/2/003 'Marine Environmental Assessment in the Black Sea Region' were subjected to detailed radiometric analysis. The sediments were dated using the radionuclides 210Pb, 137Cs and 241Am and the results used to calculate a number of key parameters, e.g. radionuclide inventories, fluxes and sediment accumulation rates. The sediment cores were collected using a MARK II-400 multi-corer (Bowers and Connelly) in both Western and Eastern sub-basins of the Black Sea. The cores were sliced on board with a resolution of 0.2-0.4 cm for the top 5 cm and 1-5 cm downward using an extruder that was specially designed to prevent loss of the uppermost fluff-layer, possible down-smearing and interlayer cross-contamination of the sediment. Dry bulk density (DBD) and cumulative dry mass (CDM) were calculated on a salt-free basis using direct determination of the salt contribution to the dry mass of the sediment. Calculations showed that in the near surface sediments, and particularly in the top fluff-layer, the salt dissolved in pore-water contributed up to 30-60% of the mass of dried sediments. Neglecting this correction could cause an erroneous interpretation of the 210Pb activity profile, resulting in overestimation of both the average sedimentation rate and its recent temporal changes. Sediment samples were analysed for 210Pb, 226Ra, 137Cs and 241Am by direct gamma assay in UHMI after 3 weeks equilibration in hermetically sealed plastic holders, using an EG and G Ortec (Ametek) HPGe GWL series well-type coaxial low background intrinsic germanium detector. Correction was made for the effect of self-absorption of low energy γ-rays within the sample using attenuation parameters determined in. Chronostratigraphical analysis of the data and sediment age calculation have

  18. Radionuclides 137Cs, 90Sr, 241Am and 239+240Pu in vegetation cover of the former Semipalatinsk test site

    The Semipalatinsk Test Site (STS) is one of the largest testing grounds for nuclear weapons. Diverse nuclear explosions were carried out on its territory: 340 underground tests (sites 'Degelen', 'Balapan' and 'Sary-Uzen'), 30 surface and 86 nuclear air explosions (site for radioactive warfare agent (RWA) and 'Experimental Field'). Since the STS was shutdown a large amount of information about current radiological situation in its territory has been collected. In recent years, one of the main problems is gradual transfer of its lands for national economy. Under these conditions, an essential element for prediction of radioactive contamination levels of food products is radionuclides redistribution parameters in soil-plant system used in calculation of doses to the population living within STS territory. Until recently, matter of radionuclides migration from soil to plants has been poorly studied. Individual researches, more or less devoted to this issue occurred in the past, but have virtually no information about accumulation of transuranic radionuclides in plants. More regular studies in this direction have been initiated recently. Between 2007 and 2013 features of artificial radionuclides accumulation in certain plant species under radioactive tunnel watercourses at 'Degelen' site were studied. We've obtained statistically reliable data characterizing accumulation of radionuclides, including 239+240Pu and 241Am, in steppe plants at 'Experimental field' site. The content of radionuclides in plants was researched at the RWA site. Comprehensive ecological survey in order to release the lands to the national economic turnover investigated parameters of radionuclides accumulation in steppe grasses at conditionally 'background' areas of STS and some parts of radioactive trace plume caused by the explosion in 1953. To date, all the findings have been generalized. We present an integrated picture about accumulation of artificial radionuclides 137Cs, 90Sr, 239+240Pu and

  19. Cosmogenic 22Na, 7Be and terrestrial 137Cs, 40K radionuclides in ground level air samples collected weekly in Krakow (Poland) over years 2003-2006

    A low background gamma spectrometer with an Etruscan, 2500 years old lead shield and a muon veto detector were applied to study 22Na and 7Be activity concentration in ground level air aerosol samples collected weekly over the years 2003-2006 in Krakow. Each sample was formed with ca 100 000 m3 of passed air, collected with two parallel ASS-500 high volume air samplers. The results for 40K and 137Cs are also presented for reference and comparison. Presented frequency distributions for activity concentration and correlation between the obtained results are discussed. The activity concentration results confirmed seasonal variation of activity to be different for all the investigated radionuclides. Moreover, the seasonal variation in nucleus activity ratio was also noticed for 22Na and 7Be. Cosmogenic radionuclides being mainly of stratospheric origin, are subsequently attached to fine aerosols, via which they are transported to the ground level air. The mean aerosol transport time within the troposphere was estimated as equal to 7.5 days on average, reaching even 50 days in warm seasons. Limitations of the applied model were identified. (author)

  20. A study of 40K and 137Cs radionuclide migration during intensive pig breeding in the Podrinje-Kolubara region of Serbia [Yugoslavia

    The obtained results pertain to the level of total beta activity (TbA), content of K i.e., A40K and A137Cs in samples of water, soil, grass, hay, major components of ''ST-1'' feed mash and pork collected in the course of the year from the Podrinje-Kolubara region in Serbia (Yugoslavia). Models for prognosis of A40K and A137Cs levels were set up. ''Selective ranks'' were determined for a40K and A137Cs. In this way a ''prognostic-selective'' model was established which is important for radiation-hygiene protection

  1. Atmospheric removal times of the aerosol-bound radionuclides 137Cs and 131I during the months after the Fukushima Dai-ichi nuclear power plant accident – a constraint for air quality and climate models

    G. Wotawa

    2012-05-01

    Full Text Available Caesium-137 (137Cs and iodine-131 (131I are radionuclides of particular concern during nuclear accidents, because they are emitted in large amounts and are of significant health impact. 137Cs and 131I attach to the ambient accumulation-mode (AM aerosols and share their fate as the aerosols are removed from the atmosphere by scavenging within clouds, precipitation and dry deposition. Here, we estimate their removal times from the atmosphere using a unique high-precision global measurement data set collected over several months after the accident at the Fukushima Dai-ichi nuclear power plant in March 2011. The noble gas xenon-133 (133Xe, also released during the accident, served as a passive tracer of air mass transport for determining the removal times of 137Cs and 131I via the decrease in the measured ratios 137Cs/133Xe and 131I/133Xe over time. After correction for radioactive decay, the 137Cs/133Xe ratios reflect the removal of aerosols by wet and dry deposition, whereas the 131I/133Xe ratios are also influenced by aerosol production from gaseous 131I. We find removal times for 137Cs of 10.0–13.9 days and for 131I of 17.1–24.2 days during April and May 2011. We discuss possible caveats (e.g. late emissions, resuspension that can affect the results, and compare the 137Cs removal times with observation-based and modeled aerosol lifetimes. Our 137Cs removal time of 10.0–13.9 days should be representative of a "background" AM aerosol well mixed in the extratropical Northern Hemisphere troposphere. It is expected that the lifetime of this vertically mixed background aerosol is longer than the lifetime of AM aerosols originating from surface sources. However, the substantial difference to the mean lifetimes of AM aerosols obtained from aerosol models, typically in the range of 3–7 days, warrants further research on the cause of this discrepancy. Too short modeled AM aerosol lifetimes would have serious implications for air quality and

  2. Atmospheric removal times of the aerosol-bound radionuclides 137Cs and 131I during the months after the Fukushima Dai-ichi nuclear power plant accident - a constraint for air quality and climate models

    Kristiansen, N. I.; Stohl, A.; Wotawa, G.

    2012-05-01

    Caesium-137 (137Cs) and iodine-131 (131I) are radionuclides of particular concern during nuclear accidents, because they are emitted in large amounts and are of significant health impact. 137Cs and 131I attach to the ambient accumulation-mode (AM) aerosols and share their fate as the aerosols are removed from the atmosphere by scavenging within clouds, precipitation and dry deposition. Here, we estimate their removal times from the atmosphere using a unique high-precision global measurement data set collected over several months after the accident at the Fukushima Dai-ichi nuclear power plant in March 2011. The noble gas xenon-133 (133Xe), also released during the accident, served as a passive tracer of air mass transport for determining the removal times of 137Cs and 131I via the decrease in the measured ratios 137Cs/133Xe and 131I/133Xe over time. After correction for radioactive decay, the 137Cs/133Xe ratios reflect the removal of aerosols by wet and dry deposition, whereas the 131I/133Xe ratios are also influenced by aerosol production from gaseous 131I. We find removal times for 137Cs of 10.0-13.9 days and for 131I of 17.1-24.2 days during April and May 2011. We discuss possible caveats (e.g. late emissions, resuspension) that can affect the results, and compare the 137Cs removal times with observation-based and modeled aerosol lifetimes. Our 137Cs removal time of 10.0-13.9 days should be representative of a "background" AM aerosol well mixed in the extratropical Northern Hemisphere troposphere. It is expected that the lifetime of this vertically mixed background aerosol is longer than the lifetime of AM aerosols originating from surface sources. However, the substantial difference to the mean lifetimes of AM aerosols obtained from aerosol models, typically in the range of 3-7 days, warrants further research on the cause of this discrepancy. Too short modeled AM aerosol lifetimes would have serious implications for air quality and climate model predictions.

  3. Comparative advantages and limitations of the fallout radionuclides (137)Cs, (210)Pb(ex) and (7)Be for assessing soil erosion and sedimentation.

    Mabit, L; Benmansour, M; Walling, D E

    2008-12-01

    The fallout radionuclides (FRNs) (137)Cs, (210)Pb(ex) and (7)Be are increasingly being used as a means of obtaining quantitative information on soil erosion and sediment redistribution rates within agricultural landscapes, over a range of different timescales, and they are frequently seen to represent a valuable complement to conventional measurement techniques. The recent development of the (7)Be method has greatly extended the timescale over which FRNs can be used, by permitting assessment of short-term soil erosion linked to individual events and changing soil management practices. This paper aims to review the advantages and limitations of each of the three FRNs and to identify key knowledge gaps linked to their use. In addition, guidelines for selecting the most appropriate FRN and associated approach, in order to deal with a range of spatial and temporal scales and to investigate specific sets of agro-environmental problems, are provided. Key requirements for future work, related to the application of FRNs in soil erosion investigations, are also identified. These include the upscaling of the approach to the catchment scale and a shift from use of the approach as a research tool to a decision support tool. PMID:18947911

  4. Comparative advantages and limitations of the fallout radionuclides {sup 137}Cs, {sup 210}Pb{sub ex} and {sup 7}Be for assessing soil erosion and sedimentation

    Mabit, L. [Soil Science Unit, FAO/IAEA Agriculture and Biotechnology Laboratory, IAEA Laboratories, A-1400 Vienna (Austria)], E-mail: l.mabit@iaea.org; Benmansour, M. [Centre National de l' Energie, des Sciences et des Techniques Nucleaires (CNESTEN), Rabat (Morocco); Walling, D.E. [University of Exeter, Department of Geography, Amory Building, Rennes Drive, Exeter EX4 4RJ (United Kingdom)

    2008-12-15

    The fallout radionuclides (FRNs) {sup 137}Cs, {sup 210}Pb{sub ex} and {sup 7}Be are increasingly being used as a means of obtaining quantitative information on soil erosion and sediment redistribution rates within agricultural landscapes, over a range of different timescales, and they are frequently seen to represent a valuable complement to conventional measurement techniques. The recent development of the {sup 7}Be method has greatly extended the timescale over which FRNs can be used, by permitting assessment of short-term soil erosion linked to individual events and changing soil management practices. This paper aims to review the advantages and limitations of each of the three FRNs and to identify key knowledge gaps linked to their use. In addition, guidelines for selecting the most appropriate FRN and associated approach, in order to deal with a range of spatial and temporal scales and to investigate specific sets of agro-environmental problems, are provided. Key requirements for future work, related to the application of FRNs in soil erosion investigations, are also identified. These include the upscaling of the approach to the catchment scale and a shift from use of the approach as a research tool to a decision support tool.

  5. Comparative advantages and limitations of the fallout radionuclides 137Cs, 210Pbex and 7Be for assessing soil erosion and sedimentation

    The fallout radionuclides (FRNs) 137Cs, 210Pbex and 7Be are increasingly being used as a means of obtaining quantitative information on soil erosion and sediment redistribution rates within agricultural landscapes, over a range of different timescales, and they are frequently seen to represent a valuable complement to conventional measurement techniques. The recent development of the 7Be method has greatly extended the timescale over which FRNs can be used, by permitting assessment of short-term soil erosion linked to individual events and changing soil management practices. This paper aims to review the advantages and limitations of each of the three FRNs and to identify key knowledge gaps linked to their use. In addition, guidelines for selecting the most appropriate FRN and associated approach, in order to deal with a range of spatial and temporal scales and to investigate specific sets of agro-environmental problems, are provided. Key requirements for future work, related to the application of FRNs in soil erosion investigations, are also identified. These include the upscaling of the approach to the catchment scale and a shift from use of the approach as a research tool to a decision support tool

  6. Determination of soil loss by 137Cs fallout radionuclide in Ömerli watershed of İstanbul, Turkey

    KIZILTAŞ, Muhammet Sahip; HACIYAKUPOĞLU, Sevilay; Gökbulak, Ferhat; HIZAL, Ahmet

    2009-01-01

    Soil erosion and sedimentation in watersheds are usually part of the information to be considered for soil and water conservation measures. Soil loss is generally estimated with models or measured with plot studies. Although fallout radionuclides (FRN) methodology provides a powerful technique for predicting the impacts of proposed land management strategies on soil erosion and sediment yield within river basins and estimates erosion based on fallout radioisotopes (Cs-137, Pb-210, Be-7) radio...

  7. The fate of long - lived radionuclides 137Cs and 90Sr in the Black Sea after Chernobyl NPP accident: results of twenty - year observations

    The presentation summarizes studies of 137Cs and 90Sr pollution of the Black Sea Basin carried out by Institute of Biology of the Southern Seas during 1986-2005 following the Chernobyl NPP accident. Its goal was to assess inflows of 137Cs and 90Sr from the Dnieper and the Danube Rivers, outflow through the Bosphorus Strait, inventories in bottom sediments and temporary evolution of 137Cs and 90Sr inventories in the Black Sea water column. Besides, the temporary evolution of 137Cs and 90Sr profiles in the Black Sea deep-water basin was used to estimations of a large-scale vertical water mixing. It has been estimated that the atmospheric fall outs during the first days of May 1986 have deposited 1.7-2.4 PBq of 137Cs on the Black Sea surface (nearly 2% of total 137Cs release in the environment). Therefore, 137Cs inventory in the 0-50 m layer have increased by a factor of 6-10 and the total 137Cs inventory in the whole basin have increased at least by a factor of 2 in comparison with the pre-Chernobyl value - 1.4+/-0.3 PBq. 137Cs input from the Danube and the Dnieper Rivers was insignificant in comparison with short-term atmospheric fall outs. The results of observations and mathematical modelling are testified that in the surface layers 0-50 and 0-200 m of the Black Sea deep-water basin in 1986-2000 an exponential decreases of the 137Cs inventories with an effective half-lifes of 5-6 years and 9-13 years, respectively, have been observed. The process of vertical water mixing has been observed mainly in the 0-200 m layer. The contribution of Chernobyl-origin 90Sr from atmospheric fallout was estimated around in 0.1-0.3 PBq. Pre-accident 90Sr level nearly 20 Bq m-3 was reached by 1988. At the same time, an active input of 90Sr from the Dnieper and Danube Rivers has been observed. The total amount of 90Sr delivered by the two rivers into the Black Sea was estimated to be nearly 0.1 PBq in the 1986-1995. Under conditions of insignificant river input and sedimentation on

  8. Application of 210Pb geochronology by the reconstruction of historical radionuclides concentrations ( 137Cs et 239+240Pu ) in the columns of the Alboran Sea

    Full text: The marine sediments are considered as a final reservoir of radioactive contaminants. The 210Pb from atmospheric fallouts deposits is stored in sediments with those from 226Ra original lithogenic. The activity of 210Pb excess in the accumulated sediment is an important tool to study the chronological process of sedimentation on recent time scales at over 100 years. However, this method should be validated using at least one independent tracer which provides an unequivocal temporal marker as 137Cs from nuclear testing. This work presents a method to rebuild historic concentrations of 137Cs and 230+240Pu in the water column Alboran Sea and their corresponding stream sediment. This is achieved by coupling the radiometric dating of the sediment column profiles using three independent levels: the excess 210Pb, 137Cs and 239 +240Pu. On the other hand, a simple model of the water column has been adapted to this end by making use of atmospheric flow, the measured values of distribution coefficient (Kd) and a first approximation of the rate of sedimentation. The timing model CM-CSR (diffusion coefficient of sedimentation rate constant) has been successfully applied to the three independent profiles, and was able to determine the parameters of diffusion and mass sedimentation rate. The results obtained give some ideas on the fate of atmospheric inputs to the marine environment and, particularly, that of the Chernobyl accident. The results of the models showed that direct and deferred contributions of Chernobyl accident are negligible in the Alboran Sea. The annual input of 210Pb to the sediment was estimated at 720±150 Bq.m-2. by year, while the rate of sedimentation is about 0092±0.003 g.cm-2 by year. On the other hand, the model could successfully reconstruct historic concentrations of 137Cs and 239+240Pu in the water column, and was able to reproduce the work of the same elements in the sediment column

  9. 137Cs metabolism during pregnancy

    Data from two pregnant women contaminated with 137 Cs, body burdens of 0.2 and 300 MBq, respectively, at the time of the Goiania accident, were compared. The first one, with lower 137 Cs body burden was exposed during the fourth month of pregnancy, while the second became pregnant three years and eight months after 137 Cs intake. For the first woman 137 Cs concentrations were similar for the mother, infant and placenta, indicating an easy and homogeneous transport of 137 Cs from mother to fetus. The whole-body monitoring data from the second woman, who became pregnant four years after intake, did not show a reduction in biological half-life during the pregnancy. Cs concentration in the mother was found to be 13 times higher than in the infant. One possible reason for this result is that four after intake. Cs is supposed to be concentrated mainly in skeletal muscle tissue. During the pregnancy the blood flux becomes higher in most of organs and tissues except brain, liver and skeletal muscle tissue. In this case, the physiological changes due to pregnancy did not modify the cesium retention. (author)

  10. Fallout radionuclides 137Cs and 7Be as an important tool to evaluate effectiveness of no-tillage systems in Central-South Chile

    Since 1970 the process of agricultural intensification has drastically increased soil erosion and associated soil degradation in the coastal mountains of south-central Chile. Due to conventional tillage (with burning of crop residues), over 80% of the soils under agriculture show evidence of compaction below plough depth and erosion rates are described amongst the highest for any agricultural land in Chile. The current study developed a simplified method for using 137Cs depth distribution datasets to estimate soil loss or accumulation at a sampling point under conventional tillage and after the shift to a no-till system. Previous applications of 137Cs measurements had been limited to the estimation of erosion rates during the period extending from the beginning of fallout receipt to the time of sampling. The new procedure allows the change in erosion rates associated with a shift in land tillage practices to be estimated. It represents an innovative application of 137Cs measurements in soil erosion research. In an additional study to assess no-till systems with and without burning of crop residues after harvesting, 7Be was used to quantify the erosion that occurred within the same field area, as a result of burning and a period of extreme rainfall (400 mm in 27 days, May 2005)

  11. Mathematical model of 137Cs dynamics in the deciduous forest

    A mathematical model of 137Cs behaviour in the forest ecosystem is presented. The behaviour of this radionuclide is assumed to obey the same regularities as the behaviour of its stable chemical analogue, potassium. Radionuclide dynamics are considered in parallel with the dynamics of the phytomass. Radionuclides contained in the vegetation are pooled into two basic compartments: external and internal contamination, with separate analysis of each. The model was verified using the data obtained in the 30-km zone of the Chernobyl NPP in 1986-1994. The algorithm described was found to be the most efficient in terms of 137Cs behaviour in the forest environments

  12. The interaction mechanisms between aqueous solutions of 137Cs and 134Ba radionuclides and local natural zeolites for an deactivation scenario

    137Cs and 134Ba were removed from synthetic aqueous solutions by means of natural zeolites of Slovakian origin. The equilibrium sorption behavior of Cs and Ba ions onto clinoptilolite and mordenite were studied under static as well as dynamic experimental conditions. Both Freundlich and Langmuir isotherms describe satisfactory by Cs and Ba adsorption on the zeolites studied. The elution of Cs and Ba ions from zeolite columns after the loading cycle was undertaken additionally, in order to compare column operating runs of various exchanged zeolite forms. (author)

  13. Study of the diffusion of trace elements and radionuclides in soils. Capillary modification of the thin layer method. Diffusion of 137Cs

    Thin layer method of measuring diffusion processes was modified to shorten time and to increase efficiency of experiments. For this purpose small and fine glass capillaries of 20 mm length and inner diameter of several millimeters were used as diffusion cells. The diffusion of trace amounts of 137Cs, its dependence on soil moisture and interaction with the soil have been studied. Experimental technique, evaluation of records and the basic interpretation of the migration process are described. (author) 19 refs.; 5 figs.; 4 tabs

  14. Long-term behaviour of 137Cs in Finnish lakes

    from 0,00007 to 0,7 in 2002. Non-predatory fish had the lowest and predatory fish the highest TFf values. Large variation in the transfer factors in 2002 reflect the joint effect of several environmental processes and factors on radionuclide distribution in lake environment during long-term after the deposition. Concentration factors, CF, (Bq/kg in fish/Bq/kg in water) of predatory fish varied from about 2800 to about 20000 in various lakes in 1998. CFs of nonpredatory fish were somewhat lower, varying from 1000 to about 5000. An example on the correlation of 137Cs concentrations in fish with those in lake water is given. The average CF for pike (Esox lucius), a predatory fish, was 6500 and that for perch (Perca fluviatilis), which is as young non-predator and as older predator, was 4400 in the lakes studied

  15. Sensitivity test of food chain model of temporal 137Cs distribution in coastal biota in case of short term introduction

    Because of the criticality accident occurred at JCO Co. Ltd. on September 30, 1999 in Tokai, Japan, short term estimation of released radionuclides behavior will be required for decision-making in emergent action. To predict radionuclide concentrations in marine organisms under short term radionuclide introduction to coastal water such as accidental situation, models of nuclide transfer both from seawater and food chain to marine organisms are studied by TATEDA (1994, 1997), TATEDA et al. (1997, 2001). The model was developed for typical Japanese coastal water including benthic food chain and planktonic food chain, with transfer parameter data set, such as uptake rate constant, excretion rate constants, gut transfer rates, food ingestion rates of 137Cs, those collected by many tracer experiment studies. Using the model verified by (calculated equilibrated concentrations)/ (observed concentrations) in biota and (calculated decrease curves of 137Cs concentrations)/(observed curves) in biota under the Chernobyl fallout introduction in Japan, we estimate the period for decontamination time of 137Cs in organisms of marine food chain under several imaginable cases. However, prediction by this model still contains uncertainty because of the variation of transfer parameters used in the model. In this study, we tested the model sensitivity for the different combinations of varied transfer parameters reported, and predicted the temporal and special distribution of 137Cs in biota in the coastal area of future nuclear fuel reprocessing plant site at Rokkasho, Aomori, Japan. The result of sensitivity analyses suggested that the effects of the variation of transfer parameters to the output of model calculations are within a range of 3 - 10 times in temporal 137Cs concentrations in coastal organisms. (author)

  16. Distribution and inventories of fallout radionuclides (239+24Pu, 137Cs) and 21Pb to study the filling velocity of salt marshes in Donana National Park (Spain)

    Within an extensive multinational and multidisciplinary project carried out in Donana National Park (Spain) to investigate its preservation and regeneration, the filling velocity of the salt marshes has been evaluated through the calculation of their average sediment accumulation rates. 239+24Pu and 137Cs from weapons testing fallout and total 21Pb distribution profiles and inventories have been determined in some of the most characteristic zones of the park, namely, the ponds (or 'lucios') and the waterjets (or 'canos'). Plutonium inventories range from 16 to 101 Bq m-2, 137Cs values fluctuate between 514 and 3758 Bq m-2 and unsupported 21Pb values comprise between 124 and 9398 Bq m-2. Average sedimentation rates range from 3 to 5 mm y-1 (1952-2002). These data are higher than those obtained by carbon dating for the period 6500 AD-present, estimated as 1.5-2 mm y-1, suggesting an increase in the accumulation of sediments and the alteration of the park's hydrodynamics caused by the re-channeling of the major rivers feeding the salt marshes

  17. 137Cs radiation burden on children from a highly contaminated area of Belarus

    The radiation burden from 137Cs sources on 22 children from a small Byelorussian village was studied from 1992 to 1994. Foodstuff, whole body burden and urinary excretion of 137Cs were measured, intake rates, biological half-lives and doses were calculated. The median value for the 137Cs whole body incorporation level was found to be 124 Bq, the biological half life was calculated as 68 d for girls and 50 d for boys. The internal dose caused by 137Cs was found to be negligible in comparison to that from external sources. No deviation from normal values could be shown in simultaneously studied clinico-chemical parameters

  18. The organic matter of forest soil as an incorporator of 137Cs

    The decomposition of a forest litter in forest ecosystems contaminated by radionuclides is accompanied by the accumulation of organomineral compounds associated with 137Cs in deeper soil layers. The highest level of 13Cs in the upper organic-reach soil layers was found in the insoluble fraction of organic matter, hemicellulose and cellulose. Due to a high level of the 137Cs accumulation in a forest litter, the last generates a substantial part of the 137Cs background in forests

  19. Radiochemical determination of {sup 137}Cs in foods

    Kastner, Geraldo F.; Ferreira, Andrea Vidal; Monteiro, Roberto P.G., E-mail: gfk@cdtn.br, E-mail: avf@cdtn.br, E-mail: rpgm@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2013-07-01

    A determination of radionuclides in food samples is important in commodities in order to attend to regulatory requirements for international trade. As a long-lived radioisotope of cesium, {sup 137}Cs is produced as a result of human nuclear activities and than its contamination level evaluation among others radionuclides in foods is necessary. A methodology for the determination of {sup 137}Cs in foods, pork and fish, is described. The procedures covered homogenization and freeze-drying of the samples. The {sup 137}Cs was measured by gamma spectrometry using Canberra 50% HPGe detector. The counting was carried out with Monte Carlo software for detection conditions optimization including geometry and chemical data information. A certified sample, SRM IAEA-375, was analyzed in order to evaluate the reliability of the method, and the results showed good agreement between the measured and certified values. (author)

  20. Some biological factors related to the 137Cs concentration of marine organisms

    Marine Ecology Research Institute has been studying the factors controlling the concentration of radionuclides in marine biota. Weight of fish seemed to be an important factor controlling the concentration of 137Cs because of the good correlation observed between the weight and the concentration of 137Cs. Food habits also seemed to be an important factor because fishes in higher trophic levels tended to indicate higher concentration factors and a positive correlation was observed between the concentrations of predator fishes and those of the foodstuff. Gender could be another factor controlling the concentration of 137Cs because the difference of 137Cs between gender was observed in rockfish and marbled sole. (author)

  1. The behaviour of 137Cs in the aquatic environment

    Through 137Cs concentration profiles in sediments from Rochedo Reservoir, it was possible to estimate the amount of this radionuclide (94 TBq) which has reached the Meia Ponte River system, as a consequence of the Goiania Radiological accident in 1987. Based on in-situ measurements as well as on laboratory studies, the influence of NH4+ concentration on the Kd value was also investigated. The results have shown that for high NH4d+ concentrations there is a clear correlation between both parameters. It was also observed the influence on the ageing effect on the 137Cs release from the sediment, as well as of the illite content on it. (author)

  2. Sorption of 137Cs from Aqueous Waste Solutions using Pottery

    A simple and inexpensive method for sorption of 137Cs from aqueous solutions using a highly available vase shape pottery material has been investigated. Porosity of the used pottery allowed for the penetration of the radioactive solution through its permeable body. Two routes had been investigated for cesium removal from the radioactive solutions. In the first one, pottery bodies were immersed into the radioactive solutions. In the second method; the radioactive solutions were filled the inner volumes of the pottery bodies. Vase shape pottery showed higher sorption capability for 137Cs much more than its powder forms, especially in the alkaline medium. Pottery bodies showed high potential for 137Cs removal. Adsorption isotherms revealed good lit to the Freundlich and Langumir isotherms. During sorption processes outside and inside the pottery body, 137Cs was well captured inside the amorphous microstructure of the pottery body. In this respect, micro filtration of cesium radionuclides through the used pottery could be postulated. Desorption experiments indicated higher immobilization affinity for radiocesium into pottery bodies, which indicates a high containment for 137Cs with an irreversible fixation mechanism

  3. Uptake of 137Cs from acidic solution by ammonium molybdophosphate (AMP) immobilized in calcium alginate

    The uptake rate for Cs+ for AMP-Ca ALG was fairly fast and the uptake attained an equilibrium within 3 hours. The observed uptake varies between 80-96% depending on the concentration of 137Cs. 137Cs is one of the major radionuclide in the effluent generated at the middle and back end of nuclear fuel cycles

  4. 137Cs in carpets of the forest moss Pleurozium schreberi, 1961-1973

    Accumulation, retention and internal cycling of the fallout radionuclide 137Cs (physical half-life=30.2 a) were studied in forest moss Pleurozium schreberi (Brid.) Mitt. collected in southern Sweden during the period 1961-1973. The highest 137Cs concentrations occurred in the green top parts of the living moss. A major part of the deposited 137Cs is available for transport from the dying to growing parts of the moss.Elimination of 137Cs from living moss, as well as from dead moss, throughout 1968-1973, can be characterized by the same mean residence time (4+-1 a). 137Cs and naturally occurring stable K show different behaviour in the moss, so that the 137Cs/K ratio is higher by a factor of approximately 2 in the dead parts of the moss than in the living parts. The vertical distribution of 137Cs in the moss-covered ground has been described theoretically. Relative penetration of 137Cs is about 5 times higher in ground covered by moss-carpets than in ground covered by lichen-carpets. Throughout 1969-1973, the total amount of 137Cs retained in the moss-carpet was 64.2+-2.2 nCi.m-2. (author)

  5. 137Cs in freshwater fish in Finland

    The paper deals with an evaluation of the importance of Finnish freshwater fish as a source of 137Cs in the diet. Freshwater fish were analysed for 137Cs in 1982. The 137Cs concentration factors from water to edible fish were determined for the same year. The evaluation is based on an extensive surface water investigation performed from 1965 to 1967. Along with the continuous fallout monitoring since the beginning of the 1960'es, this material makes it possible to valuate the 137Cs levels in surface water right up to the 1980'es. In 1982 the Finns received an average of 90 Bq 137Cs from freshwater fish. This dose constitutes a quarter of the 137Cs uptake from the total food consumtion in Finland in 1982

  6. Behavior of 137Cs concentrations in the North Pacific in an ocean general circulation model

    Tsumune, Daisuke; Aoyama, Michio; Hirose, Katsumi

    2003-08-01

    We have carried out a first simulation of the spatial distributions and the temporal variations of 137Cs concentrations in the North Pacific in off line calculations by using archived output of an ocean general circulation model (OGCM) developed by the National Center of Atmospheric Research (NCAR). Artificial radionuclides including 137Cs are introduced into ocean surface due to global fallout originating from the large-scale atmospheric nuclear weapons tests in 1961-1962. The distribution of radioactive deposition used as forcing for this simulation is estimated from global precipitation data and observed values of annual deposition of radionuclides at the Meteorological Research Institute (MRI) in Japan. 137Cs originating from global fallout have been transported into the ocean interior by advection and diffusion, and the 137Cs concentrations reduced by radioactive decay. We assess the skill of the model calculations by comparing simulated values of 137Cs in seawater with the observed values included in the database compiled by MRI because 137Cs is one of the most useful tracers regarding water motion in the ocean. The vertical and horizontal distributions of the calculated 137Cs concentrations were in good agreement with those of the observed 137Cs concentrations, except in the deep layer.

  7. Long-term ingestion dose monitoring in a population group with increased 137Cs intake

    137Cs amounts and ingestion doses in Czech population have been monitored by whole-body counting since the Chernobyl accident. Indirect estimation of the retention through measurement of 137Cs excreted with urine in 24 hours has also been performed since 1987. The 137Cs content in human body can be calculated from the urine data provided that the intake of 137Cs during the period of interest is constant. In a semi-natural environment, the 137Cs content in mushrooms, wild berries and game decreases due to its natural decay solely. The 137Cs content in people who mostly consume venison and have been living in an area with elevated contamination has been monitored, mostly through measurement of 137Cs in urine. In parallel, measurements with a mobile whole-body counter have also been performed. Currently, annual doses from the ingestion of 137Cs in the inhabitants are very low (0.001 to 0.002 mSv.year-1). In a group of hunters in the Jeseniky Mountains (Northern Moravia) the doses were estimated to 0.10 mSv.year-1. (orig.)

  8. The spread of 137Cs by resuspension of contaminated soil in the urban area of Goiania

    Measurements regarding the population exposure were performed in Goiania after the radiological accident as well as studies on resuspension and redeposition of 137Cs in urban areas, on the contribution of soil splash to the 137Cs uptake by leafy vegetables and on the transfer of 137Cs from soil to chicken meat and eggs. Periodical street dust sampling was used to follow-up the spreading of the radionuclide in the city. The results do not indicate a measurable spreading of this radionuclide throughout the city from the contaminated areas, but resuspension can lead to significant local contamination of agricultural products, equipment, structures, etc. (author)

  9. 137Cs and 40K partitioning in the system soil-plant under different ecological conditions

    In the environment 137Cs is exclusively of the anthropogenic origin. Among different released fission radionuclides, 137Cs is the most significant one as it contributes to long-term doses to population. It belongs to the group of radionuclides which under accidental situations can disperse worldwide because of air mass transport. 137Cs deposition in the Lithuanian terrestrial and aquatic ecosystems is basically related to the global fallout and contaminated air masses from the Chernobyl NPP accident. An extra load of 137Cs to the Lithuanian terrestrial ecosystems was determined after the Fukushima Daiichi NPP accident as well. Over the recent decades evident changes in the approach to the radiation protection of non-human species from ionizing radiation have taken place. Furthermore, long-term predictions of the mobility and bioavailability of 137Cs are required because of its penetration into the food chain. 40K is a typical lithophilic element and its geochemistry could be similar to that of 137Cs because they both are of the same valence state, +1. Investigation results of 137Cs and 40K behavior in the environmental systems in the literature are rather contradictory. Therefore, the aim of the present study is to assess 137Cs and 40K activity concentration in soil and various plants of a different root system and to compare bioavailability of these radionuclides under different environmental ecological conditions. 137Cs deposition distribution in the upper soil layer is different in the studied territory. The mean 137Cs activity concentrations in soil and plants in the post-Chernobyl period varied in a wide range. 137Cs activity concentrations in soil varied from about 30 Bq/kg to 340 Bq/kg, while in various plants and grasses the range was 45-119 Bq/kg. Mean values of the 137Cs transfer factor ranged from 0.1 to 1.4. The discrimination factor was determined to evaluate the effect of 40K activity concentration in soil and plants on distribution of 137Cs in plants

  10. Uptake of 90Sr and 137Cs by mushrooms following the Chernobyl accident

    After the Chernobyl accident high concentrations of radionuclides were found in Sweden in mushrooms and the contents of 90Sr and 137Cs were measured. The level of 90Sr was generally low and, in proportion to 137Cs, 2-3 orders of magnitude lower than in the fallout. The contents of 137Cs varied among species, while the geographical distribution of the radioactivity largely followed the soil deposition. Extreme local variation occurred and the ratio 134Cs/137Cs diverged from other biological samples leading to the conclusion that old fallout was involved in the uptake. Transfer factors calculated for the uptake of 137Cs exhibited no correlation with the fallout levels, being mainly correlated with the different species. The problems associated with the definition of transfer factors for mushrooms were discussed. (author)

  11. Intake estimation and dose assessment of 90Sr, 137Cs around QNPP base

    90Sr and 137Cs are important radionuclides in environmental investigation related to nuclear power stations. A mode of intake estimation and dose assessment via various food chains is made in this paper. Based on daily food consumption and dietary composition for Chinese reference man and for man of Zhejiang province and the concentration of 137Cs and 90Sr around QNPP Base, the intake estimation and dose of 90Sr and 137Cs around QNPP Base are calculated. It shows that the main food sources of intake of 90Sr and 137Cs are rice,vegetable and aquatic product. Also the public average annual committed effective dose of 90Sr(2.5 μSv)is obviously higher than the contribution of dose of the 137Cs(0.36 μSv). A practical estimation method was made by taking QNPP Base as an example in this paper, while no background change occurs after its commercial operation. (authors)

  12. Atmospheric deposition of radioactive cesium (137Cs) associated with dust events in East Asia

    Since the cessation of atmospheric nuclear testing in 1980, there has been no known serious atmospheric contamination by radioactive cesium (sup(137)Cs) apart from the Chernobyl nuclear reactor accident in 1986. There now remain only small amounts of anthropogenic radionuclides in the atmosphere that can be directly related to past testing. However, sup(137)Cs is still regularly found in atmospheric deposition samples in Japan. In this study, we analyzed sup(137)Cs monitoring data, meteorological data, and field survey results to investigate the recent transport and deposition of sup(137)Cs associated with dust phenomena. Monthly records of nationwide sup(137)Cs deposition in Japan during the 1990s show a consistent seasonal variation, with higher levels of deposition occurring in spring. In March 2002, an unexpectedly high amount of sup(137)Cs was deposited in the northwestern coastal area of Japan at the same time as an Asian dust event was observed. Analysis of land-based weather data showed that sandstorms and other dust-raising phenomena also occurred in March 2002 over areas of Mongolia and northeastern China where grassland and shrubs predominated. Furthermore, radioactivity measurements showed sup(137)Cs enrichment in the surface layer of grassland soils in the areas affected by these sandstorms. These results suggest that grasslands are potential sources of sup(137)Cs-bearing dust. Continued desertification of the East Asian continent in response to recent climate change can be expected to result in an increase in sup(137)Cs-bearing soil particles in the atmosphere, and their subsequent re-deposition in Japan. However, soil dust is also raised around Japanese monitoring sites by the strong winds that are common in Japan in spring, and this local dust might also contribute to sup(137)Cs deposition in Japan. To estimate the relative contributions of local and distant dust events to the total sup(137)Cs deposition, we monitored deposition of mineral particles

  13. 90Sr and 137Cs in higher aquatic plants of the Chernobyl NPP exclusion zone

    The content of 90Sr and 137Cs radionuclides in higher aquatic plants of water object within Chernobyl NPP exclusion zone has been analysed. Biodiversity of phytocenose was studied and species-indicators of radioactive contamination were revealed. The seasonal dynamics of radionuclide content in macrophytes was studied and the role of main aquatic plant clumps in processes of 90Sr and 137Cs distribution in abiotic component of biohydrocenose was demonstrated

  14. [90Sr and 137Cs in higher aquatic plants of the Chernobyl nuclear plant exlusion zone

    Gudkov, D I; Derevets, V V; Kuz'menko, M I; Nazarov, A B

    2001-01-01

    The content of radionuclides 90Sr and 137Cs in higher aquatic plants of water objects within Chernobyl NPP exclusion zone has been analysed. Biodiversity of phytocenose was studied and species-indicators of radioactive contamination were revealed. The seasonal dynamics of radionuclide content in macrophytes was studied and the role of main aquatic plant clumps in processes of 137Cs and 90Sr distribution in abiotic component of biohydrocenose was demonstrated. PMID:11402559

  15. Phytoremediation of 137Cs from low level nuclear waste using Catharanthus roseus

    Remediation of radionuclides has been carried out using the phytoremediation technology. The green plants have been screened for the uptake potential of radionuclide and found that Catharanthus roseus has the high potential for radionuclides in particular 137Cs. Low level nuclear waste (LLNW) collected from effluent treatment plant, BARC has been characterized for physico-chemical and the presence of traces of radionuclides. LLNW was spiked with 3.7 x 104 kBqL-1 activity level of 137Cs. The plants of C. roseus were grown in (i) LLNW, (ii) 137Cs spiked LLNW and (iii) with the control. The radio activities were measured in the solution at the intervals of 0, 1, 2, 3, 6, 8 and 15 days in triplicate set of the experiment. The plants were harvested after the growth. The depletion of 137Cs in LLNW was found to be 19, 21, 24, 38, 60 and 76% at intervals of 1, 2, 3, 6, 8 and 15 days, respectively. The bio-accumulation of 137Cs has been measured in the roots and shoots of the harvested plants. The activity of 137Cs was found higher in shoots (998 kBq g-1 dw) as compared to the roots (735 kBq g-1 dw). The uptake of radionuclide-137Cs, bio-accumulation in the shoot via the active transport from the root, shows the high efficiency and potentiality of C. roseus for the remediation of radionuclide. The bio-accumulation of 137Cs in the shoot will remediate the radionuclide contamination from LLNW. C. roseus can also be made applicable for effective remediation of radionuclides present in the LLNW. (author)

  16. {sup 137}Cs applicability to soil erosion assessment: theoretical and empirical model; Aplicabilidade do {sup 137}Cs para medir erosao do solo: modelos teoricos e empiricos

    Andrello, Avacir Casanova

    2004-02-15

    The soil erosion processes acceleration and the increase of soil erosion rates due to anthropogenic perturbation in soil-weather-vegetation equilibrium has influenced in the soil quality and environment. So, the possibility to assess the amplitude and severity of soil erosion impact on the productivity and quality of soil is important so local scale as regional and global scale. Several models have been developed to assess the soil erosion so qualitative as quantitatively. {sup 137}Cs, an anthropogenic radionuclide, have been very used to assess the superficial soil erosion process Empirical and theoretical models were developed on the basis of {sup 137} Cs redistribution as indicative of soil movement by erosive process These models incorporate many parameters that can influence in the soil erosion rates quantification by {sup 137} Cs redistribution. Statistical analysis was realized on the models recommended by IAEA to determinate the influence that each parameter generates in results of the soil redistribution. It was verified that the most important parameter is the {sup 137} Cs redistribution, indicating the necessity of a good determination in the {sup 137} Cs inventory values with a minimum deviation associated with these values. After this, it was associated a 10% deviation in the reference value of {sup 137} Cs inventory and the 5% in the {sup 137} Cs inventory of the sample and was determinate the deviation in results of the soil redistribution calculated by models. The results of soil redistribution was compared to verify if there was difference between the models, but there was not difference in the results determinate by models, unless above 70% of {sup 137} Cs loss. Analyzing three native forests and an area of the undisturbed pasture in the Londrina region, can be verified that the {sup 137} Cs spatial variability in local scale was 15%. Comparing the {sup 137} Cs inventory values determinate in the three native forest with the {sup 137} Cs inventory

  17. 137Cs in northern Adriatic sediments

    The activity of 137Cs in shallow northern Adriatic sediments was obtained on the basis of measurement results from 25 sediment box cores, sampled during the Adriatic Scientific COoperation Program (ASCOP) 16 cruise in the summer 1990. 137Cs was determined in surface sediments (0-3 cm) and 12-15 cm-deep sediment. It was found that the lowest caesium concentrations correspond to sands, which are spread along the Croatian coast. Parallel to the Italian coast, 137Cs concentrations in pelites are the highest. It seems that the influence of Po River is significant for 137Cs activities in recent marine sediments along Italian coast south of Po River delta. Significantly higher 137Cs activities in 0-3 cm sediment layer can be attributed to the deposition caused by Chernobyl accident. (author)

  18. Assessment of 137Cs Activity Concentration in Soil from Tea Plantation Areas in Cameron Highlands

    137Cs is well known man-made radionuclide produced from nuclear industry. Nuclear weapon tests and nuclear accidents had contributed to presence of 137Cs into the worldwide environment including Malaysia. It has spread out to the entire world through the air and water current. Since Cameron Highlands is located at high altitude, there is a better chance of the 137Cs to settle down on the trees and later the soil underneath. In this study, the soil samples were taken at the slopes of two different tea plantation areas namely A and B. The soil samples were oven dried, ground, sieved and packed and sealed properly in plastic containers before measurement. Each plastic container contains around 450 g of sample. The measurement of 137Cs activity concentration was done using HPGe detector gamma spectrometer. The spectrum was analyzed using Gamma Vision software to calculate the activity concentration of 137Cs with energy peak of 661.66 keV. The activity concentration of 137Cs found in the samples ranged from 0.23 to 1.90 and 0.11 to 3.01 Bq/ kg for tea plantation A and tea plantation B, respectively. From the activity concentration of 137Cs result, it was comparable to the others research regarding to 137Cs in the soil around Asian. (Author)

  19. Specific Activities and Radioactive Contour Maps of Natural (238U, 232Th, 226Ra and 40K ) and Anthropogenic (137Cs) Radionuclides in Beach Sand Samples Collected from Nai Yang Beach of Phuket Province After Tsunai Disaster

    Full text: Specific activities of natural (238U, 232Th, 226Ra and 40K) and artificial anthropogenic (137Cs) radionuclides in 50 beach sand samples collected from Nai Yang beach in Phuket province which was effected from 2004 tsunami disaster, have been studied and measured. Experimental results were obtained by using a high-purity germanium (HPGe) detector and gamma spectrometry analysis system and also evaluated by using the standard reference materials IAEA/RGU-1, IAEA/RGTh-1, KCL and SL-2 which were obtained from Department of Physics, Faculty of Science, Prince of Songkhla University Hat Yai Campus. Experimental set-up and measurements were operated and carried out at Nuclear and Material Physics Laboratory in Department of Physics, Faculty of Science, Thaksin University Songkhla Campus. It was found that, the beach sand specific activity ranges from 862.50 to 3,356.35 Bq/kg for 40K, 3.51- 28.58 Bq/kg for 226Ra, 10.15 to 30.22 Bq/kg for 232Th and 0.00 to 2.39 Bq/kg for 137Cs with mean values of 1,843.03 ± 152.49 Bq/kg, 14.88 ± 3.30 Bq/kg, 19.19 ± 2.80 Bq/kg and 0.14 ± 0.11 Bq/kg, respectively. Furthermore, the results were also used to evaluate the absorbed dose rates in air (D), the radium equivalent (Raeq), the external hazard index (Hex) and the annual effective dose rate (AED) in all beach area. Moreover, experimental results were also compared to the Office of Atoms for Peace (OAP) research data, Thailand and global radioactivity measurements and evaluation, the recommended values which were proposed by the Organization for Economic Cooperation and Development (OECD, 1979) and United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR, 1988, 1993, 2000). Specific activities of natural and artificial anthropogenic radionuclides in all of Nai Yang beach sand samples could be also used to create the radioactive contour maps

  20. Dispersal of the radionuclide caesium-137 (137Cs) from point sources in the Barents and Norwegian Seas and its potential contamination of the Arctic marine food chain: Coupling numerical ocean models with geographical fish distribution data

    Dispersal of 137Cs from the nuclear submarine wrecks Komsomolets and K-159, which are resting on the seabed in the Norwegian and Barents Seas, respectively, is simulated using realistic rates and hypothetical scenarios. Furthermore, spatiotemporal 137Cs concentrations in Northeast Arctic cod and capelin are estimated based on survey data. The results indicate that neither continuous leakages nor pulse discharges will cause concentrations of 137Cs in cod muscle or whole body capelin exceeding the intervention level of 600 Bq/kg fw. Continuous leakages from Komsomolets and K-159 and pulse discharges from Komsomolets induced negligible activity concentrations in cod and capelin. A pulse discharge of 100% of the 137Cs-inventory of K-159 will, however, result in concentrations in muscle of cod of above 100 times the present levels in the eastern Barents Sea. Within three years after the release, 137Cs levels above 20 Bq/kg fw in cod are no longer occurring in the Barents Sea. -- Highlights: •The dispersal of 137Cs from the wrecks of Komsomolets and K-159 are simulated. •The submarine wrecks are resting on the seabed in the Norwegian and Barents Seas. •Both realistic rates of discharges and what-if scenarios are simulated. •Concentrations of 137Cs are estimated in observational records of cod and capelin. •Only pulse discharges from K-159 causes high 137Cs concentrations in cod and capelin. -- A pulse discharge of 137Cs from K-159 may cause concentrations in muscle of cod up to 63 and 123 Bq/kg fresh weight in the near-surface and near-bottom layer, respectively

  1. Distribution of 137Cs in soil samples of Goa environment

    Systematic studies on distribution of 137Cs in soil samples of Goa region have been carried out using gamma spectrometric technique. Soil samples were collected from different places of Goa region and studied their depth profile and seasonal variation of the activity. Efforts have been to find the correlation between this radionuclide concentration and the soil organic matter content and possible inferences were drawn. (author)

  2. Biokinetic model for 137 Cs

    The main objective of this work was to provide a realistic biokinetic model for 137 Cs metabolism. This model was based on the retention of cesium in 57 people contaminated in the Goiania accident, ages 1 to 73 y old, complemented by data obtained in an experiment with beagle dogs, and data taken from the open literature. Cesium is distributed among all tissues and organs of the body. Its main retention site is the skeletal muscle tissue. Mathematically, cesium retention in the body may be described by a sum of three terms exponential equation. The first term represents the fraction which is rapidly eliminated in urine. This fraction is weight dependent (negative correlation). The second term represents the retention of cesium in tissues and organs of the body. For children and adolescents, the second term biological half-life is a function of the weight. For adults, it is correlated with sex. Men present a higher retention of cesium than women. The third term correspond to a retention fraction of the order of 0,1% of the initial body burden. It is characterized by a very long half-life and represents a subcellular retention of cesium in the skeletal muscle tissue. During pregnancy the transfer factor from the mother to the fetus is correlated to the amount of cesium in the blood and it is equal to 1, if the intake of cesium occurs pregnancy. (author)

  3. {sup 137}Cs in marine sediments of Admiralty Bay, King George Island, Antarctica

    Ferreira, Paulo Alves de Lima [Instituto Oceanográfico, Universidade de São Paulo (IO-USP), Pça. do Oceanográfico, 191, Butantã, SP, 05508 900 (Brazil); Ribeiro, Andreza Portella, E-mail: andrezpr@usp.br [Instituto Oceanográfico, Universidade de São Paulo (IO-USP), Pça. do Oceanográfico, 191, Butantã, SP, 05508 900 (Brazil); Mestrado de Gestão Ambiental e Sustentabilidade, Universidade Nove de Julho (UNINOVE), Avenida Francisco Matarazzo, 612, prédio C, andar térreo, Água Branca, São Paulo, SP, 05001 100 (Brazil); Nascimento, Mylene Giseli do; Martins, Cesar de Castro [Centro de Estudos do Mar, Universidade Federal do Paraná (CEM-UFPR), Av. Beira-mar, no number, Balneário Pontal do Sul, Pontal do Paraná, PR, 83255 971 (Brazil); Mahiques, Michel Michaelovitch de; Montone, Rosalinda Carmelo; Figueira, Rubens Cesar Lopes [Instituto Oceanográfico, Universidade de São Paulo (IO-USP), Pça. do Oceanográfico, 191, Butantã, SP, 05508 900 (Brazil)

    2013-01-15

    The radionuclide cesium-137 ({sup 137}Cs) is produced exclusively by anthropogenic processes and primarily by nuclear explosions. This study determined the reference inventory that is {sup 137}Cs associated with the element's original input, and utilized the levels of activity of this radionuclide previously measured in five sediment profiles collected from Admiralty Bay, Antarctica, to investigate the mobility of this element in the environment. {sup 137}Cs has a half-life of 30 years. Because of this, it is environmentally persistent and has been shown to accumulate in marine organisms. The mean reference inventory of this radionuclide in Admiralty Bay sediments, determined using high resolution gamma ray spectrometry, was 20.23 ± 8.94 Bq m{sup −2}, and within the ambient {sup 137}Cs activity range. A model of {sup 137}Cs diffusion–convection was applied to data collected from 1 cm intervals in sediment cores with the aim of providing insights with respect to this element's behavior in sediments. Model results showed a significant correlation between measured and modeled values using the concentrations of {sup 137}Cs, and estimated input into the system from the global fallout of past nuclear tests and expected values based on local sedimentation rates. Results highlight the importance of accounting for the vertical diffusion of {sup 137}Cs in marine sediments when used as a tracer for environmental processes and for assessing potential bioavailability. - Highlights: ► Cesium-137 ({sup 137}Cs) is produced exclusively by anthropogenic processes. ► A model of diffusion–convection simulated {sup 137}Cs environmental behavior. ► This is important for assessing the bioavailability of this toxic element. ► In Antarctica ice cover influenced the input to the sediments.

  4. 137Cs in marine sediments of Admiralty Bay, King George Island, Antarctica

    The radionuclide cesium-137 (137Cs) is produced exclusively by anthropogenic processes and primarily by nuclear explosions. This study determined the reference inventory that is 137Cs associated with the element's original input, and utilized the levels of activity of this radionuclide previously measured in five sediment profiles collected from Admiralty Bay, Antarctica, to investigate the mobility of this element in the environment. 137Cs has a half-life of 30 years. Because of this, it is environmentally persistent and has been shown to accumulate in marine organisms. The mean reference inventory of this radionuclide in Admiralty Bay sediments, determined using high resolution gamma ray spectrometry, was 20.23 ± 8.94 Bq m−2, and within the ambient 137Cs activity range. A model of 137Cs diffusion–convection was applied to data collected from 1 cm intervals in sediment cores with the aim of providing insights with respect to this element's behavior in sediments. Model results showed a significant correlation between measured and modeled values using the concentrations of 137Cs, and estimated input into the system from the global fallout of past nuclear tests and expected values based on local sedimentation rates. Results highlight the importance of accounting for the vertical diffusion of 137Cs in marine sediments when used as a tracer for environmental processes and for assessing potential bioavailability. - Highlights: ► Cesium-137 (137Cs) is produced exclusively by anthropogenic processes. ► A model of diffusion–convection simulated 137Cs environmental behavior. ► This is important for assessing the bioavailability of this toxic element. ► In Antarctica ice cover influenced the input to the sediments

  5. Uptake, retention and organic/tissue distribution of 137Cs by Japanese catfish (Silurus asotus linnaeus)

    Full text: This works describes the uptake, retention/biological elimination of 137Cs by Japanese Catfish (Silurus asotus linnaeus) under laboratory conditions. The fish were divided in to three groups viz. large, medium and small and reared in to the host water contaminated by 137Cs. The accumulated 137Cs concentration in the whole body of the fish was measured at certain intervals up to 60 days. A significant accumulation of 137Cs was found but a steady state accumulation of 137Cs was not achieved by the end of the experiment. The bioaccumulation factors and the distribution of the radionuclide in different organs/tissues of the fish were determined. To determine the effective half-life, the fish were transferred and reared into the non contaminated host water. The concentration of the radionuclide in the whole body of the fish was measured up to 66 days. Neglecting the small first compartment for a few days, the average effective half-life of 137Cs in the fish species was found to be ∼ 30 days for all size of fish. Accumulation of 137Cs in muscle/flesh of the fish was found to be ∼ 75% of whole body accumulation. (author)

  6. Heavy element radionuclides (Pu, Np, U) and {sup 137}Cs in soils collected from the Idaho National Engineering and Environmental Laboratory and other sites in Idaho, Montana, and Wyoming

    Beasley, T.M.; Rivera, W. Jr. [Dept. of Energy, New York, NY (United States). Environmental Measurements Lab.; Kelley, J.M.; Bond, L.A. [Pacific Northwest National Lab., Richland, WA (United States); Liszewski, M.J. [Bureau of Reclamation (United States); Orlandini, K.A. [Argonne National Lab., IL (United States)

    1998-10-01

    The isotopic composition of Pu in soils on and near the Idaho National Engineering and Environmental Laboratory (INEEL) has been determined in order to apportion the sources of the Pu into those derived from stratospheric fallout, regional fallout from the Nevada Test Site (NTS), and facilities on the INEEL site. Soils collected offsite in Idaho, Montana, and Wyoming were collected to further characterize NTS fallout in the region. In addition, measurements of {sup 237}Np and {sup 137}Cs were used to further identify the source of the Pu from airborne emissions at the Idaho Chemical Processing Plant (ICPP) or fugitive releases from the Subsurface Disposal Area (SDA) in the Radioactive Waste Management Complex (RWMC). There is convincing evidence from this study that {sup 241}Am, in excess of that expected from weapons-grade Pu, constituted a part of the buried waste at the SDA that has subsequently been released to the environment. Measurements of {sup 236}U in waters from the Snake River Plain aquifer and a soil core near the ICPP suggest that this radionuclide may be a unique interrogator of airborne releases from the ICPP. Neptunium-237 and {sup 238}Pu activities in INEEL soils suggest that airborne releases of Pu from the ICPP, over its operating history, may have recently been overestimated.

  7. Risk from radionuclides: a frog's perspective : Accumulation of 137Cs in a riparian wetland, radiation doses, and effects on frogs and toads after low-dose rate exposure

    Stark, Karolina

    2006-01-01

    Threats from man-made radionuclides include waste issues, increasing number of power plants, underground bomb testing, nuclear weapons, and “dirty bombs”. Until recently the ionizing radiation protection system focused on protecting humans with an implied protection of biota. However, goals of sustainable development and precautionary principles for human activity are leading to an inclusion of plant and animal populations in the protection system. From this perspective, the present thesis ex...

  8. Sequential determination of natural (232Th, 238U) and anthropogenic (137Cs, 90Sr, 241Am, 239+240Pu) radionuclides in environmental matrix

    A new sequential method for the determination of both natural (U, Th) and anthropogenic (Sr, Cs, Pu, Am) radionuclides has been developed for application to soil and sediment samples. The procedure was optimised using a reference sediment (IAEA-368) and reference soils (IAEA-375 and IAEA-326). Reference materials were first digested using acids (leaching), 'total' acids on hot plate, and acids in microwave in order to compare the different digestion technique. Then, the separation and purification were made by anion exchange resin and selective extraction chromatography: Transuranic (TRU) and Strontium (SR) resins. Natural and anthropogenic alpha radionuclides were separated by Uranium and Tetravalent Actinide (UTEVA) resin, considering different acid elution medium. Finally, alpha and gamma semiconductor spectrometer and liquid scintillation spectrometer were used to measure radionuclide activities. The results obtained for strontium-90, cesium-137, thorium-232, uranium- 238, plutonium-239+240 and americium-241 isotopes by the proposed method for the reference materials provided excellent agreement with the recommended values and good chemical recoveries. (authors)

  9. Transfer of 137Cs into mother's milk

    The concern of nursing mothers about the contamination of foodstuffs after Chernobyl prompted this investigation of radiocaesium transfer to mother's milk. Between May 1987 and December 1988, duplicates of daily food intakes, as well as the corresponding mothers' milk samples, were collected from 12 nursing mothers for two to four weeks in order to measure the 137Cs activity. Once during the collection period, the total-body activity of each of the mothers involved was measured. Based on our results, 137Cs is transferred into mother's milk not only directly from food intake but also from the accumulated body burden. Approximately 19% of the 137Cs activity from the daily food intake and about 13% of the specific 137Cs body activity of the mother are transferred into 1 litre of mother's milk. (author)

  10. 137Cs and 90Sr aerosol-carriers origination when welding radioactively contaminated metal structures

    The results of research of main parameters of welding process influence to 137Cs and 90Sr radionuclides transition regularity in a welding aerosol are demonstrated. The 137Cs specific activity in welding aerosol decreases according to power law with lessening of surface activity of plates being welded on, and depends on content of electrode cover and does not depend on welding heat input. Respirable fraction activity of welding aerosol exceeds at 20 - 30 % the welding aerosol activity as a whole.

  11. 137Cs and 210Pb distribution in Manila Bay sediment

    Two radionuclides were measured in surface sediment samples taken from geographically distributed sections of Manila Bay, namely cesium-137 (137Cs) and lead-210 (210Pb). Results indicated a noticeable change in the radioactivity concentration levels in sediments collected in 2005 and 2010, with a median concentration of 1.0 and 2.64 Bq kg-1, respectively. Higher levels of 137Cs radioactivity were measured in the northern and inner portion of the bay adjacent to major river systems, agricultural and highly industrialized urban areas. 137Cs isotope increased in activity in most of the samples especially in the northwestern areas of Bataan and Pampanga with five times more than the activity from the first sampling measurements. Nevertheless, radioactivity concentrations observed in surface sediments along the bay are within the range of radioactivity in several areas monitored in the Northern Hemisphere. The country has been frequented by tropical cyclones and storms that have caused erosion, which may have introduced elevated material input in the bay. In addition, wind-driven circulation especially in the shallower areas of the bay is a possibility for the substantial sediment movement and accumulation along this coast. Conversely, areas with higher 137Cs have lower values of 210Pb. In an undisturbed environment, 210Pb deposition values are assumed nearly constant. Hence, changes in the radioactivity concentration levels of these radionuclides can be an indicator of pollution input from land-based sources, sediment movement and reworking in the coastal areas. At present, there is very limited information on the radioactivity level of various radioisotopes in Manila Bay.The data obtained are benchmark values against which changes that will be occurring in the bay can be assessed. (author)

  12. 137Cs applicability to soil erosion assessment: theoretical and empirical model

    The soil erosion processes acceleration and the increase of soil erosion rates due to anthropogenic perturbation in soil-weather-vegetation equilibrium has influenced in the soil quality and environment. So, the possibility to assess the amplitude and severity of soil erosion impact on the productivity and quality of soil is important so local scale as regional and global scale. Several models have been developed to assess the soil erosion so qualitative as quantitatively. 137Cs, an anthropogenic radionuclide, have been very used to assess the superficial soil erosion process Empirical and theoretical models were developed on the basis of 137 Cs redistribution as indicative of soil movement by erosive process These models incorporate many parameters that can influence in the soil erosion rates quantification by 137 Cs redistribution. Statistical analysis was realized on the models recommended by IAEA to determinate the influence that each parameter generates in results of the soil redistribution. It was verified that the most important parameter is the 137 Cs redistribution, indicating the necessity of a good determination in the 137 Cs inventory values with a minimum deviation associated with these values. After this, it was associated a 10% deviation in the reference value of 137 Cs inventory and the 5% in the 137 Cs inventory of the sample and was determinate the deviation in results of the soil redistribution calculated by models. The results of soil redistribution was compared to verify if there was difference between the models, but there was not difference in the results determinate by models, unless above 70% of 137 Cs loss. Analyzing three native forests and an area of the undisturbed pasture in the Londrina region, can be verified that the 137 Cs spatial variability in local scale was 15%. Comparing the 137 Cs inventory values determinate in the three native forest with the 137 Cs inventory value determinate in the area of undisturbed pasture in the

  13. Behavior of 131I and 137Cs in environments released from the Fukushima nuclear disaster

    Ohta, T.; Mahara, Y.; Kubota, T.; Igarashi, T.

    2011-12-01

    The devastating tsunami that caused by the great earthquake (M = 9.0) off the coast of northeastern Honshu on 11 March 2011 destroyed large coastal areas of Tohoku and north Kanto, Japan. Radionuclides, including 131I, 134Cs, and 137Cs, were released into the atmosphere from the Fukushima Daiichi plants. Concentration of levels of 131I, 134Cs, and 137Cs in Ibaraki Prefecture, Japan, released from the Fukushima Daiichi plant were investigated in the soil and precipitation. The concentrations of 131I and 137Cs in the soil from the surface to 1 cm depth in Ibaraki Prefecture were 9360-13,400 Bq/kg and 720-3250 Bq/kg, respectively. The concentration of 137Cs at this soil observation site originating from the Fukushima plant was 8.4 to 21 times that found locally after the Nagasaki atomic bomb explosion. Most of the 134Cs and 137Cs from rainwater were trapped by the surface soil and sand to a depth of 1 cm, whereas only about 30% of the 131I was collected by the surface soil, suggesting that 131I would move deeper than 137Cs and 134Cs. The 131I in the rainwater was in the anion exchangeable form, and all of it could be collected by anion exchangeable mechanisms, whereas 30% of the 131I that had passed through the soil could not be trapped by the anion exchange resin, suggesting that the chemical form of this 30% was in a changeable, organic-bound form. The 131I, 134Cs, and 137Cs that were absorbed on soil were difficult to be dissolved into water. As the half-life of 131I is short and 137Cs is strongly adsorbed on the surface soil and sand, these radionuclides would be unlikely to reach the groundwater before completely decaying; contamination of groundwater with 131I and 137Cs supplied from rainwater to the surface soil is therefore exceedingly unlikely. As the 137Cs is likely to migrate only 0.6 cm in 10 years, people living in the Fukushima and Kanto areas will be exposed to radiation from 137Cs in the surface soil and sand. For protection, surface soils and sands

  14. Investigation and evaluation of 137Cs and 90Sr migration from soil to conifer trees

    Pliopaitė Bataitienė, Ingrida

    2011-01-01

    In this dissertation is analysed the transfer of artificial radionuclides (137Cs and 90Sr) from soil to tree. The main goal of this work – to estimate specific activi-ties of 137Cs and 90Sr in selected trees, investigate the peculiarities of these ra-dionuclides distribution in trees, suggest the methodology for estimation of the transfer of radionuclides from soil to tree in tree wood by chemical analog in soil under the tree crown, and to do the forecast of transfer of radionuclides in sys-...

  15. Modelling of 137Cs behaviour in the soil-plant system following the application of ameliorants

    A set of countermeasures aimed at reducing 137Cs uptake by plant products includes agrochemical measures based on changes in the soil properties after the application of ameliorants. The dynamic models for studying the effect of the application of potassium fertilizers and dolomite powder on 137Cs accumulation in plants are presented. Conceptual approaches to the development of models are based on the identification of mechanisms governing a complex of physico-chemical processes in soil after the use of ameliorants. The following assumptions were used in the development of models: - dynamics of 137Cs distribution in each soil layer depends on the sorption processes characterized by different time to achieve quasi-equilibrium (exchangeable uptake and fixation by clay minerals) as well as on vertical migration process; - change in 137Cs content in soil solution results from the radionuclide sorption on selective and nonselective exchange sites; - uptake of extra amounts of K+ and Ca2+ in soil solution produces effect on processes of 137Cs exchangeable sorption and initiate specific processes responsible for 137Cs fixation in the crystal lattice of clay minerals; - Ca2+ and K+ cations have a competing effect on 137Cs uptake by plants from soil solution, which along with the fixation processes, causes lower accumulation of this radionuclide by plants during the application of ameliorants. The developed models were parameterized for soils of the coniferous forest located in the Bryansk region in area suffered from the radioactive fallout after the Chernobyl accident. Effects of ameliorants and time of their application on 137Cs behaviour in the soil-plant system are assessed. The contribution of soil chemical and biological processes to the decrease in the radionuclide uptake by plants is estimated. (author)

  16. Peculiarities of 137Cs translocation in higher plants under environmental and laboratory conditions

    Accumulation of technogenic 137Cs in higher plant roots and above-ground part and comparison of 137Cs and 40K transfer from roots to the above-ground part of plant as well as distribution within above-ground part of plant under environmental conditions were investigated. Parallely, the results of the investigations of 137Cs accumulation in the roots and shoots of test-organism Lepidium sativum L. in the model hydroponic system aqueous solution-solid phase-plant were analyzed. Peculiarities of transfer of this radionuclide from roots to shoots during the entire plant growing period under experimental conditions were determined. 137Cs activity in the tested plants of meadow ecotop was on an average 6-fold lower than in the plants of swamp and 10-fold lower than in the plants of forest ecotop. Differences in 137Cs and 40K transfer from roots to the above-ground part of plant and their distribution in plants indicate particular biological metabolism of these radionuclides in plants. Increased levels of 137Cs in soil practically did not affect the 40K transfer from roots to the above-ground part of plants. The results of investigations under natural and laboratory conditions show that increasing contamination of growth medium with 137Cs caused higher accumulation of this radionuclide in roots but its transfer from roots to the above-ground part of plant decreased or changed insignificantly. 137Cs transfer from roots to above-ground part under natural (Artemisia vulgaris) and laboratory (Lepidium sativum) conditions was rather similar. (authors)

  17. Distributions of 137Cs and 210Pb in moss collected from Belarus and Slovakia

    In the present work, moss samples collected in Slovakia and Belarus were assayed with respect to gamma-emitting radionuclides. The results for 137Cs and 210Pb are discussed. Moss was used for the first time in Belarus, as a biological indicator of radioactive environmental pollution in consequence of the Chernobyl accident in 1986. In Belarus, the maximum activity of 137Cs was observed in the Gomel region near Mazyr (6830 Bq/kg) and the minimum activity in the Vitebsyevsk Region near Luzhki-Yazno (5 Bq/kg). “Hot spots” were also observed near the towns Borisow and Yuratsishki. The results of measurements of 137Cs in moss samples collected in 2000, 2006 and 2009 in the same localities of Slovakia are presented and compared with the results of air monitoring of 137Cs carried out in Slovakia from 1977 until 2010. Measurements of the 210Pb concentration in moss samples collected over the territory of Slovakia showed, that the median value exceed 2.3 times median value of 210Pb obtained for Belarus moss. For that reason, the inhalation dose for man from 210Pb and 137Cs in Slovakia is more than twice as high as in Belarus, in spite of the initially very high 137Cs exposure in the latter country. -- Highlights: ► Belarus moss was used as a biological indicator of 137Cs and 210Pb. ► Comparison with concentration of 137Cs and 210Pb in moss from Slovakia. ► Moss samples reflect the original distribution of Chernobyl fallout in Belarus. ► Regular decrease of the annual average activity of 137Cs in surface air in Slovakia. ► Median concentration of 210Pb in moss from Belarus is 2.3 times lower than in Slovakia

  18. Modelling the distribution of 90Sr and 137Cs in the Mediterranean Sea (MTPII-MATER)

    Within the frame of the MTPII-MATER project (MAST), the distribution of 90Sr and 137Cs in the Mediterranean Sea was modelled, as these radionuclides are useful tracers of water circulation. The Mediterranean Sea was divided into 81 boxes, corresponding to 21 regions, taking into account water mass circulation, bathymetry and data availability. Transfer rates were obtained from the MOM model run under MEDMEX conditions. The model was run with realistic inputs, which included weapons global fallout, Chernobyl 137Cs, nuclear industry and river runoff. It was observed that existing data are scarce, especially in the eastern Mediterranean. In general, model predictions agreed well with observations, showing maximum concentrations in surface waters and maxima due to global fallout (137Cs and 90Sr) and to the Chernobyl accident (137Cs only). (author)

  19. The 137Cs accumulation by forest-derived products in the Gomel region

    This paper reports basic features of the 137Cs uptake by forest-derived products in the Gomel region. Even with the soil contamination density of 37 kBq m−2 the radionuclide contents in 20–30% of mushrooms and berries were found to be higher than the admissible levels. The 137Cs contamination density of soil, site type and meteorological parameters were observed as the major factors which govern the radiocaesium uptake by mushrooms and berries. The 137Cs contents in forest-derived products were found to increase directly with the soil contamination density. Bilberries (Vaccinium myrtillus) growing on different site types differed significantly in the 137Cs content. It was also determined that statistically significant differences in the 137Cs radioactivity of forest foods growing on different natural sites were governed by the factor designated in the current study by “territorial”. The differences are to be accounted for both by forms of the Chernobyl fallout and by the natural and climatic conditions determining variations in the availability of radionuclides in the soil. In dry years the 137Cs concentrations in some mushroom species were higher than in normal years

  20. Sampling soils for 137Cs using various field-sampling volumes

    The sediments from a liquid effluent receiving area at the Los Alamos National Laboratory and soils from intensive study area in the fallout pathway of Trinity were sampled for 137Cs using 25-, 500-, 2500-, and 12 500-cm3 field sampling volumes. A highly replicated sampling program was used to determine mean concentrations and inventories of 137Cs at each site, as well as estimates of spatial, aliquoting, and counting variance components of the radionuclide data. The sampling methods were also analyzed as a function of soil size fractions collected in each field sampling volume and of the total cost of the program for a given variation in the radionuclide survey results. Coefficients of variation (CV) of 137Cs inventory estimates ranged from 0.063 to 0.14 for Mortandad Canyon sediments, where CV values for Trinity soils were observed from 0.38 to 0.57. Spatial variance components of 137Cs concentration data were usually found to be larger than either the aliquoting or counting variance estimates and were inversely related to field sampling volume at the Trinity intensive site. Subsequent optimization studies of the sampling schemes demonstrated that each aliquot should be counted once, and that only 2 to 4 aliquots out of an many as 30 collected need be assayed for 137Cs. The optimization studies showed that as sample costs increased to 45 man-hours of labor per sample, the variance of the mean 137Cs concentration decreased dramatically, but decreased very little with additional labor

  1. (137)Cs distributions in soil and trees in forest ecosystems after the radioactive fallout - Comparison study between southern Finland and Fukushima, Japan.

    Pumpanen, Jukka; Ohashi, Mizue; Endo, Izuki; Hari, Pertti; Bäck, Jaana; Kulmala, Markku; Ohte, Nobuhito

    2016-09-01

    The nuclear accidents at Chernobyl and Fukushima released large amounts of (137)Cs radionuclides into the atmosphere which spread over large forest areas. We compared the (137)Cs concentration distribution in different parts of two coniferous forest ecosystems (needle litter, stems and at different depths in the soil) over short and long term periods in Finland and Japan. We also estimated the change in (137)Cs activity concentrations in needle and soil between 1995 and 2013 in Southern Finland based on the back-calculated (137)Cs activity concentrations. We hypothesized that if the (137)Cs activity concentrations measured in 1995 and 2013 showed a similar decline in concentration, the (137)Cs activity concentration in the ecosystem was already stable in 1995. But if not, the (137)Cs activity concentrations were still changing in 2013. Our results showed that the vertical distribution of the (137)Cs fallout in the soil was similar in Hyytiälä and Fukushima. The highest (137)Cs concentrations were observed in the uppermost surface layers of the soil, and they decreased exponentially deeper in the soil. We also observed that (137)Cs activity concentrations estimated from the samples in 1995 and 2013 in Finland showed different behavior in the surface soil layers compared to the deep soil layer. These results suggested that the (137)Cs nuclei were still mobile in the surface soil layers 27 years after the accident. Our results further indicated that, in the aboveground parts of the trees, the (137)Cs concentrations were much closer to steady-state when compared to those of the surface soil layers based on the estimated declining rates of (137)Cs concentration activity in needles which were similar in 1995 and 2013. Despite its mobility and active role in the metabolism of trees, the (137)Cs remains in the structure of the trees for decades, and there is not much exchange of (137)Cs between the heartwood and surface layers of the stem. PMID:27158060

  2. Spatial 137Cs distribution in forest soil

    This work presents the distribution of radioactive caesium in several types of forest soil originating from the Lesisko reserve (Opole Province, Poland). Vertical distribution of 137Cs isotope was determined in the profiles related to physicochemical properties of different types of soils and their location. Thickness of emerging genetic horizons, structure and morphology of soil profiles were determined. The highest 137Cs activities were found in Of and A horizons. At the same time, there was a sudden drop of 137Cs activity in mineral horizons of soil profiles. By analysis of caesium radioisotope content and its distribution in soil profiles significant correlations were observed between certain physicochemical properties (e.g. pH value, hydrolytic acidity, granulometric composition) of soils in selected forest habitats. (author)

  3. 137Cs distribution in sod-podzol forest soil of Ukrainian Polissia

    137Cs distribution in sod-podzol forest soil of Ukrainian Polissia in different types of forest condition is studied. Rates of specific and total radionuclides activity in the layers of forest floor and in the mineral part of soil are analyzed. According to the qualitative study of 137Cs distribution in the soil of pine plantation the forest floor is considered to be the geochemical barrier for the migration of radionuclides into soil. The highest total radionuclide activity in humus-eluvial horizon is observed

  4. Plutonium as a chronomarker in Australian and New Zealand sediments: a comparison with (137)Cs.

    Hancock, G J; Leslie, C; Everett, S E; Tims, S G; Brunskill, G J; Haese, R

    2011-10-01

    The construction of high resolution chronologies of sediment profiles corresponding to the last 50-100 years usually entails the measurement of fallout radionuclides (210)Pb and (137)Cs. The anthropogenic radionuclide, (137)Cs, originating from atmospheric nuclear weapons testing can provide an important "first appearance" horizon of known age (1954-1955), providing much-needed validation for the sometimes uncertain interpretations associated with (210)Pb geochronology. However, while (137)Cs usually provides a strong signal in sediment in the northern hemisphere, total fallout of (137)Cs in the southern hemisphere was only 25% that of the north and the low activities of (137)Cs seen in Australian and New Zealand sediments can make its horizon of first appearance somewhat arguable. Low (137)Cs fallout also limited the size of the 1963-1964 fallout peak, a peak that is usually seen in northern hemisphere sediment profiles but is often difficult to discern south of the equator. This paper shows examples of the use of nuclear weapons fallout Pu as a chronomarker in sediment cores from Australia (3 sites) and New Zealand (1 site). The Pu profiles of five cores are examined and compared with the corresponding (137)Cs profiles and (210)Pb geochronologies. We find that Pu has significant advantages over (137)Cs, including greater measurement sensitivity using alpha spectrometry and mass spectrometric techniques compared to (137)Cs measurements by gamma spectrometry. Moreover, Pu provides additional chronomarkers associated with changes in the Pu isotopic composition of fallout during the 1950s and 1960s. In particular, the (238)Pu/(239+240)Pu activity ratio shows distinct shifts in the early 1950s and the mid to late 1960s, providing important known-age horizons in southern hemisphere sediments. For estuarine and near-shore sediments Pu sometimes has another significant advantage over (137)Cs due to its enrichment in bottom sediment relative to (137)Cs resulting from the

  5. Plutonium as a chronomarker in Australian and New Zealand sediments: a comparison with {sup 137}Cs

    Hancock, G.J., E-mail: gary.hancock@csiro.au [CSIRO Land and Water, Black Mountain Laboratories, GPO Box 1666, Canberra, ACT 2601 (Australia); Leslie, C. [CSIRO Land and Water, Black Mountain Laboratories, GPO Box 1666, Canberra, ACT 2601 (Australia); Everett, S.E.; Tims, S.G. [Department of Nuclear Physics, Research School of Physics and Engineering, The Australian National University, Building 57, Canberra, ACT 0200 (Australia); Brunskill, G.J. [84 Alligator Creek Road, Alligator Creek, Queensland 4816 (Australia); Haese, R. [Geoscience Australia, GPO Box 378, Canberra, ACT 2601 (Australia)

    2011-10-15

    The construction of high resolution chronologies of sediment profiles corresponding to the last 50-100 years usually entails the measurement of fallout radionuclides {sup 210}Pb and {sup 137}Cs. The anthropogenic radionuclide, {sup 137}Cs, originating from atmospheric nuclear weapons testing can provide an important 'first appearance' horizon of known age (1954-1955), providing much-needed validation for the sometimes uncertain interpretations associated with {sup 210}Pb geochronology. However, while {sup 137}Cs usually provides a strong signal in sediment in the northern hemisphere, total fallout of {sup 137}Cs in the southern hemisphere was only 25% that of the north and the low activities of {sup 137}Cs seen in Australian and New Zealand sediments can make its horizon of first appearance somewhat arguable. Low {sup 137}Cs fallout also limited the size of the 1963-1964 fallout peak, a peak that is usually seen in northern hemisphere sediment profiles but is often difficult to discern south of the equator. This paper shows examples of the use of nuclear weapons fallout Pu as a chronomarker in sediment cores from Australia (3 sites) and New Zealand (1 site). The Pu profiles of five cores are examined and compared with the corresponding {sup 137}Cs profiles and {sup 210}Pb geochronologies. We find that Pu has significant advantages over {sup 137}Cs, including greater measurement sensitivity using alpha spectrometry and mass spectrometric techniques compared to {sup 137}Cs measurements by gamma spectrometry. Moreover, Pu provides additional chronomarkers associated with changes in the Pu isotopic composition of fallout during the 1950s and 1960s. In particular, the {sup 238}Pu/{sup 239+240}Pu activity ratio shows distinct shifts in the early 1950s and the mid to late 1960s, providing important known-age horizons in southern hemisphere sediments. For estuarine and near-shore sediments Pu sometimes has another significant advantage over {sup 137}Cs due to its

  6. Geochronological reconstruction of the long-term inflow of 137Cs to the Black Sea from mountain and lowland rivers and comparison of the buffer capacity of watersheds

    The trends of radionuclide discharge from the Danube and Coruh rivers were traced using the 137Cs deposition records in the adjacent Black Sea sediments. The 137Cs-derived dating showed that the maximum discharge of 137Cs from the Coruh was delayed for 14 years relative to the date of the Chernobyl accident, reflecting a buffer effect of watershed soils. This transit time is 3 and 1.5 times langer than that in the Danube and Dnieper, respectively, indicating a difference in retention processes in these mountain and lowland catchment basins. The 137Cs profile in Coruh sediments showed the penetration of 137Cs to much greater depth than it would be expected from the 137Cs fallout chronology, suggesting the sediment mixing at a rate of 1.3 cm2y-1. This value was used to evaluate the deposition chronology of bomb 137Cs, applying the model developed for pulse fallout case. The higher measured activities of 137Cs in the upper sediments, relative to modelled data, may be explained by an additional 137Cs input with eroded soil particles. Subtracting the measured and modelled data allows the differentiation of 137Cs trends of the flood-induced discharge and the slower transit of 137Cs from the catchment basin

  7. Changes in the forms of 137Cs and its availability for plants as dependent on properties of fallout after the Chernobyl nuclear power plant accident

    The dynamics of exchangeable and acid soluble 137Cs content in soils, as well as 137Cs transfer factors for natural vegetation were studied for different sites within a 50-km zone around the Chernobyl nuclear power plant after the 1986 accident. Changes in 137Cs forms in soils during the 6 years after the accidental release of radioactive substances and availability of this radionuclide to plants at that time were dependent on the character of radioactive fallout (fuel particles, aerosols of different dispersion) and soil type. Transformation of different 137Cs species in soils with time after the accident was observed (destruction of fuel particles, ageing of 137Cs and changes in the 137Cs sorption strength of the soil solid phase). Behaviour of 137Cs in the 'near' and 'remote' zones was different. The content of exchangeable 137Cs in soils was found to have decreased after the accident. The average half-life of 137Cs in grass stand in dry meadow in the 'remote' zone is 3.5 years, and in the second (slower) period after the accident, this half-life for 137Cs will amount to about 17 years. The 137Cs transfer factors for peaty swamped soils were 3.7-6.6 times as high as for soils of automorphous series

  8. Individual Radiological Protection Monitoring of Utrok Atoll Residents Based on Whole Body Counting of Cesium-137 (137Cs) and Plutonium Bioassay

    Hamilton, T; Kehl, S; Brown, T; Martinelli, R; Hickman, D; Jue, T; Tumey, S; Langston, R

    2007-06-08

    This report contains individual radiological protection surveillance data developed during 2006 for adult members of a select group of families living on Utrok Atoll. These Group I volunteers all underwent a whole-body count to determine levels of internally deposited cesium-137 ({sup 137}Cs) and supplied a bioassay sample for analysis of plutonium isotopes. Measurement data were obtained and the results compared with an equivalent set of measurement data for {sup 137}Cs and plutonium isotopes from a second group of adult volunteers (Group II) who were long-term residents of Utrok Atoll. For the purposes of this comparison, Group II volunteers were considered representative of the general population on Utrok Atoll. The general aim of the study was to determine residual systemic burdens of fallout radionuclides in each volunteer group, develop data in response to addressing some specific concerns about the preferential uptake and potential health consequences of residual fallout radionuclides in Group I volunteers, and generally provide some perspective on the significance of radiation doses delivered to volunteers (and the general Utrok Atoll resident population) in terms of radiological protection standards and health risks. Based on dose estimates from measurements of internally deposited {sup 137}Cs and plutonium isotopes, the data and information developed in this report clearly show that neither volunteer group has acquired levels of internally deposited fallout radionuclides specific to nuclear weapons testing in the Marshall Islands that are likely to have any consequence on human health. Moreover, the dose estimates are well below radiological protection standards as prescribed by U.S. regulators and international agencies, and are very small when compared to doses from natural sources of radiation in the Marshall Islands and the threshold where radiation health effects could be either medically diagnosed in an individual or epidemiologically discerned in a

  9. {sup 137}Cs and {sup 40}K partitioning in the system soil-plant under different ecological conditions

    Luksiene, B. [Center for Physical Sciences and Technology (Lithuania); Marciulioniene, D. [Nature Research Centre (Lithuania)

    2014-07-01

    In the environment {sup 137}Cs is exclusively of the anthropogenic origin. Among different released fission radionuclides, {sup 137}Cs is the most significant one as it contributes to long-term doses to population. It belongs to the group of radionuclides which under accidental situations can disperse worldwide because of air mass transport. {sup 137}Cs deposition in the Lithuanian terrestrial and aquatic ecosystems is basically related to the global fallout and contaminated air masses from the Chernobyl NPP accident. An extra load of {sup 137}Cs to the Lithuanian terrestrial ecosystems was determined after the Fukushima Daiichi NPP accident as well. Over the recent decades evident changes in the approach to the radiation protection of non-human species from ionizing radiation have taken place. Furthermore, long-term predictions of the mobility and bioavailability of {sup 137}Cs are required because of its penetration into the food chain. {sup 40}K is a typical lithophilic element and its geochemistry could be similar to that of {sup 137}Cs because they both are of the same valence state, +1. Investigation results of {sup 137}Cs and {sup 40}K behavior in the environmental systems in the literature are rather contradictory. Therefore, the aim of the present study is to assess {sup 137}Cs and {sup 40}K activity concentration in soil and various plants of a different root system and to compare bioavailability of these radionuclides under different environmental ecological conditions. {sup 137}Cs deposition distribution in the upper soil layer is different in the studied territory. The mean {sup 137}Cs activity concentrations in soil and plants in the post-Chernobyl period varied in a wide range. {sup 137}Cs activity concentrations in soil varied from about 30 Bq/kg to 340 Bq/kg, while in various plants and grasses the range was 45-119 Bq/kg. Mean values of the {sup 137}Cs transfer factor ranged from 0.1 to 1.4. The discrimination factor was determined to evaluate the

  10. 90Sr and 137Cs accumulation by live and dead lichens

    Experimental data on the accumulation and fixation strength of two long-living fragment radionuclides (90Sr and 137Cs) in live and dead lichens are given. It is shown that the mechanisms of 90Sr absorption by lichens from aqueous solutions are based mainly on physico-chemical sorption, whereas the 137Cs absorption depends largely on the physiological-biochemical processes related to metabolic plant activity. The long confinement of 90Sr and 137Cs in lichens is explained by the extremely instable water regime resulting in a rather long dehydration of lichens when leaching of radionuclides from plants with the weakly-mineralized waters is retarded. It is indicated that the liberation of lichens from radionuclides with thallome parts dying off annually can not be essential due to the longevity of these plant forms, their slow growth and dying off

  11. Peculiarities of 90 Sr and 137 Cs behavior in the atmosphere and the hydrosphere

    Physical and chemical forms of 137 Cs, 90 Sr carriers were investigated in the atmosphere, river and sea water and bottom sediments. The physico-chemical forms of aerosol-radionuclide carriers of artificial radionuclides (137 Cs and 90 Sr), having arrived to the territory of Lithuania after the Chernobyl accidents, were also investigated. Considerable differences were detected in the properties of carriers of radionuclides of secondary pollution, which resulted from the wind transport of dust and combustion products from forests and peat-bogs fires and dust storms in the greatly polluted territories of the Ukraine and Belarus. The time-course of physico-chemical forms of 137 Cs shows properties and concentration variations in the atmosphere in 1994-1995. (author)

  12. 137Cs: A Widely Used and Validated Medium Term Soil Tracer

    Radioactive Caesium-137 (137Cs) is found globally in the environment due to fallout after nuclear weapon testing in the fifties and sixties, and nuclear accidents in the more recent past. The properties and particular features of 137Cs (half-life of about 30 years), such as its strong adsorption to soil particles, make it an exceptional and the most widely used soil tracer for studying soil movement processes. The 137Cs method that possesses a number of major advantages over traditional approaches to document erosion and deposition rates, provides estimates of soil redistribution averaged over a period of several decades. It has been employed to study soil redistribution under different agro-ecological conditions in many different areas of the world. 137Cs has been also used in soil erosion investigations over a wide range of geographic scales, extending from experimental plots, through fields of a few hectares to small watersheds of several km2. This method has been validated by many international peer-reviewed studies that compared erosion rates obtained with 137Cs, other tracers, direct measurements at various scales and/or traditional soil erosion modelling. Significant progress has been made in harmonizing protocols for application of 137Cs-based soil erosion research through cooperation of specialist teams and coordination by the International Atomic Energy Agency (IAEA). The development, refinement and calibration of the 137Cs method have provided a universal and mature tool to quantify soil redistribution rates in a range of natural and agro-ecosystems, and have paved the way for a wider application of the technique, particularly in assessing the effectiveness of soil conservation technologies in controlling or mitigating soil erosion and associated degradation processes. This paper explains the fundamental principles of the use of fallout radionuclides for soil erosion assessments based on the example of 137Cs. (author)

  13. 137Cs metabolism in pregnant women

    Data from two pregnant women contaminated with 137Cs, body burdens of 0.2 and 300 MBq, respectively at the time of the Goiania accident, were compared. The first one, with lower body burden was exposed during the fourth month of pregnancy, while the second became pregnant three years and eight months after 137Cs intake. For the first woman 137Cs concentrations were equal for the mother, infant and placenta, indicating an easy and homogeneous transport of 137Cs from mother to foetus. The whole body monitoring data from the second woman, who became pregnant four years after intake, did not show a reduction in biological half-life during the pregnancy. Cs concentration in the mother was found to be 13 times higher than in the infant. One possible reason for this result is that four years after intake, Cs is supposed to be concentrated mainly in skeletal muscle tissue. During the pregnancy the blood flux becomes higher in most of the organs and tissues except brain, liver and skeletal muscle tissue. (author)

  14. Fallout 137Cs activity and associated dose in the coastal marine environment of India

    Coastal marine environment is important for India since a considerable percentage of the human population resides in coastal areas. Fallout radionuclides as well as non-radioactive substances have polluted the coastal marine environment of India. The introduction of 137Cs, a fallout radionuclide, considered as global pollutant, into marine environment has created the need for marine environmental data. The main objective is to provide data on the present level of 137Cs that is important from the standpoint of radiological health and dose associated with it. Such database will also provide benchmark that will be helpful in assessing the impact of additional contribution to marine radioactivity in the future. (author)

  15. 137Cs in forest ecosystems in Estonia

    Full text: In the recently published 'Europe's Environment' (1995) one can find the map on 137Cs cumulative deposition in Europe after the Chernobyl accident (source: De Corte et al., 1990). On this map most of the Eastern Europe including Baltic Sea region is practically uncovered. In this reason we decided to present data on accumulation of 137Cs in the forest ecosystems in Estonia. Field sampling for current study has been conducted in 1986 - 1994. 137Cs concentrations were measured in different compartments of model trees, ground vegetation layers, debris and topsoil. The amount of 137Cs varied from 1.9 kBq/m2 in continental Estonia to 28.8 kBq/m2 in north-eastern Ne part of Estonia. The results obtained correspond to data presented in Wahlstroem et al., (1992) for Finland. According to the 'Europe's Environment' criteria northeastern Estonia belongs to the third cumulative deposition zone (10 to 32 kBq/m2). In Estonia the total deposition of 137Cs varies in the range from practically zero to 3.9 kBq/m2 . The calculations of Realo et al. (1994) back to May 1, 1986 gave figures from 0 to 21 kBq/m2. In macro lichens Cetraria, Cladina, Cladonia the rapid changes in 137Cs concentrations were observed: 0.06 - 0.18 kBq/kg in 1982-85, 0.93 - 6.23 kBq/kg in 1986-87, 0.27 -4.26 kBq/kg in 1988-89, 0.05 - 1.46 kBq/kg in 1990-91 and, finally, 0.03 - 0.46 kBq/kg in 1993-94. At the end of the observation period average value of the 137Cs concentrations was the same as maximum before the CRA and decline of the concentrations was 4 times during six years. Average concentrations of 137Cs in two common forest mosses Pleurozium shreberi and Hylocomium splendens was 0.43 kBq/kg of dry matter and in forest debris 0.38 kBq/kg. In 1986 the highest concentration in mushrooms - 16.6 kBq/kg was found in Lactarius sp. (Martin, L., et al., 1991). In 1991 samples of 41 different mushroom species from 63 sample sites mostly in Scots pine stands were analyzed. The highest concentration of

  16. Estimation of whole-body content of 137Cs from a single urine sample. Experience from areas in Russia contaminated after the Chernobyl accident

    Between 1991 and 1997 measurements of the body burden of 137Cs were performed in people living in the Bryansk region of Russia. A single urine sample was also collected for many of the measured persons. The possibility of estimating the whole-body 137Cs from a single urine sample was investigated by comparing the body burden of 137Cs derived from field measurements with data on the urinary excretion of 137Cs, using various normalisation parameters. Coefficients for assessing the body burden from a single urine sample were calculated for each method. The in vivo measurements were carried out using a 63 mm diam. x 63 mm NaI(Tl) detector and a single-channel analyser in villages in the Bryansk region of Russia, in September each year. The urine samples were collected from adults as well as from children, and later analysed for 137Cs, potassium and creatinine concentrations. The correlation between whole-body content and urinary excretion of 137Cs did not improve by introducing potassium or creatinine normalisation. This study indicates that the most reliable method to estimate 137Cs body burden from urine analysis is simply to use the concentration of 137Cs. Age and sex dependent factors for the calculation of 137Cs body burden from a single urine sample are presented. (author)

  17. Fractionation of 137Cs and Pu in natural peatland

    High Cs-137 concentrations in plants growing on peatland inspired us to investigate the quantity of its bioavailable fraction in natural peat. Our investigation aims to: a) estimate the quantity of bioavailable Cs-137 and Pu present in peat, b) verify the similarity of Cs-137 and K-40 behaviours, and c) perform a quantification of Cs-137 and Pu transfer from peat to plants. We analysed the vertical distribution of Cs-137 and Pu isotopes in the peat and their concentrations in plants growing on these places. Bioavailability of radionuclides was investigated by sequential extraction. Sequential analyses revealed that it was the upper layer which contained the majority of Cs-137 in an available form while deeper layers retained Cs-137 in immobile fractions. We can conclude that 18% of all Cs-137 in the peat is still bioavailable. Despite of the low quantity of bioavailable fraction of Cs-137 its transfer factor reached extremely high values. In the case of Pu, 64% of its total amount was associated with fulvic/humic acids which resulted in the high transfer factor from peat to plants. 27 years after the Chernobyl nuclear accident, the significant part of radionuclides deposited in peatland is still bioavailable. - Highlights: • Decrease of exchangeable 137Cs and its increase in residual fraction with depth. • High 137Cs transfer factor contrary to its low quantity in bioavailable fractions. • Fulvic/humic acids are a more effective carrier for Pu than for Cs

  18. 131I and 137Cs removal from cheese, upon immersion in a sodium chloride solution

    Cheese samples have been ripened, using milk artificially contaminated with radioactive 137Cs and 131I. Tests have been carried out to investigate the effect of brine (18%W/V NaCl) on the radionuclide concentration in the cheese. The removal percent of both radionuclides is 45% at least for the first 24 hours of immersion and it was increased at about 5% in the next 48 hours. An attempt was made to examine the reverse situation. Cheese curd from uncontaminated milk was immersed in the brine which had been injected with 131I or 137Cs. It may be concluded that brine may act as a ''purifier'' of cheese curd in the case of 131I and 137Cs removal. (Author)

  19. In situ measurements of density of 137Cs contamination of the forest system in Ukraine

    The Chernobyl accident resulted in significant contamination of Ukrainian territory by various radionuclides. The activity of the main dose forming radionuclide released into the environment, 137Cs, was estimated to be approximately 3.1 x 1016 Bq. The density of surface contamination of different natural systems by 137Cs is the characteristic used for assessment and prediction of the radioecological situation. For validation of the in situ method and study of migration processes, the inventory of 137Cs (activity per unit area) was determined through a combination of in situ spectrometry using a NaI(Tl) detector and of soil samples analyses of numerous Ukrainian forest sites for the past 3 years. 5 refs, 2 figs, 2 tabs

  20. Transport of 131I and 137Cs from air to cows milk produced in north-western Italian farms following the Chernobyl accident

    After the Chernobyl accident, the levels of 131I and 137Cs were measured in surface air, pasture grass and milk produced by cows fed exclusively on fresh grass. The observed values of the vegetation-to-air, milk-to-vegetation and milk-to-air concentration ratios were compared with the values predicted by an internationally recognized assessment model for the transfer of radionuclides through terrestrial food chains. Predicted values were higher than the observed results by factors of 2.6, 2.1 and 5.6 for 131I and 4.3, 3.7 and 16 for 137Cs, for the vegetation-to-air, milk-to-vegetation and milk-to-air ratios, respectively. A better agreement between prediction and observation was achieved by using experimental values of the following parameters; the mass interception factor (R/Y), the effective decay constants on vegetation (λν) and the milk transfer coefficients (Fm), these being lower than the model default values. Milk produced by dairy cows fed on a mixed diet showed a different behaviour with regard to excretion of 137Cs. (author)

  1. Biological effects of 137Cs, incorporated into organism of rats

    Results of investigating mutagenous and hemotoxic effects of 137Cs on blood lymphocytes of rats are presented. 137Cs was orally administrated into organism of rats as 270 kBq/g chloride solution. 137Cs mutagenous effect was studied on metaphase plates of rat blood lymphocytes in course of rats lifetime experiment. It is stated that 137Cs inducing severe disturbances of genetic material in a great quantity of blood lymphocytes, causes their total killing

  2. Spatial distribution of fallout 137Cs in coastal marine water of Tamil Nadu coast

    Very little information on the fallout 137Cs activity exists for the Bay of Bengal. Normally the volume of sea water required for detecting fall out level of 137Cs in coastal marine environment ranges from 100 litres to 1000 litres. The studies on distribution of 137Cs in surface seawater of Tamil Nadu in Bay of Bengal were carried out in April 2009. On the eastern coastal lines of Bay of Bengal in Tamil Nadu, seven offshore locations were selected namely Chennai, Pondicherry, Karaikal, Rameshwaram, Tuticorin, Nagercoil and Kanyakumari. In situ preconcentration method was adopted and the experiments were carried out using motor boats well equipped to carry the instruments and provide power supply to operate the pump. 1000 litres of seawater was passed each time through CFCN filters at all the locations at a flow rate of 8 litres per minute. The activity concentrations of 137Cs was in the range of 0.90 to 2.2 Bq/m3. These data represents reference values for coastal environment of Tamil Nadu and will be used to estimate radionuclide inventory in Indian marine environment, particularly of East Coast. The 137Cs activity indicates that there are no new inputs of these radionuclides into the area. (author)

  3. Quantitative Model for Estimating Soil Erosion Rates Using 137Cs

    YANGHAO; GHANGQING; 等

    1998-01-01

    A quantitative model was developed to relate the amount of 137Cs loss from the soil profile to the rate of soil erosion,According th mass balance model,the depth distribution pattern of 137Cs in the soil profile ,the radioactive decay of 137Cs,sampling year and the difference of 137Cs fallout amount among years were taken into consideration.By introducing typical depth distribution functions of 137Cs into the model ,detailed equations for the model were got for different soil,The model shows that the rate of soil erosion is mainly controlled by the depth distrbution pattern of 137Cs ,the year of sampling,and the percentage reduction in total 137Cs,The relationship between the rate of soil loss and 137Cs depletion i neither linear nor logarithmic,The depth distribution pattern of 137Cs is a major factor for estimating the rate of soil loss,Soil erosion rate is directly related with the fraction of 137Cs content near the soil surface. The influences of the radioactive decay of 137Cs,sampling year and 137Cs input fraction are not large compared with others.

  4. The association of 137Cs with various components of tea leaves fermented from Chernobyl contaminated green tea

    The distribution of137Cs among various components of fermented tea leaves harvested after the Chernobyl accident was investigated by applying a sequential extraction procedure. An association of the radioisotope with the phenolic moiety of a phenylglucoside was detected in black tea infusate using permeation chromatography as well as UV and NMR spectroscopy. The chemical structure of a 137Cs containing compound also isolated from an artificially 137Cs labelled aqueous extract of green leaves was compared to that of fermented tea leaves. The implications of the findings on the chemical forms of the radionuclide are discussed

  5. Uptake of {sup 137}Cs by fresh water fish

    Man, C.K.; Kwok, Y.H

    2000-02-01

    The uptake and discharge rates of {sup 137}Cs by fresh water fish at different radionuclide concentrations have been studied. A dual compartment model was used to fit the experimental data. The discharge rates have been found to be negligible for the duration of the experiment of 10 days. The uptake rates were independent of radionuclide concentrations for a particular type of fresh water fish and were different for different types of fish. The uptake rates of carp, tilapia and snakehead were 1.58, 1.66 and 2.23, in unit of 10{sup -6} h{sup -1}, respectively. It was also estimated that the consumption of fresh water fish, even if the water were contaminated as much as that in the Chernobyl accident, leads to negligible latent cancer fatality to the Hong Kong population.

  6. Uptake of 137Cs by fresh water fish

    The uptake and discharge rates of 137Cs by fresh water fish at different radionuclide concentrations have been studied. A dual compartment model was used to fit the experimental data. The discharge rates have been found to be negligible for the duration of the experiment of 10 days. The uptake rates were independent of radionuclide concentrations for a particular type of fresh water fish and were different for different types of fish. The uptake rates of carp, tilapia and snakehead were 1.58, 1.66 and 2.23, in unit of 10-6 h-1, respectively. It was also estimated that the consumption of fresh water fish, even if the water were contaminated as much as that in the Chernobyl accident, leads to negligible latent cancer fatality to the Hong Kong population

  7. Reactive barriers for 137Cs retention

    137Cs was dispersed globally by cold war activities and, more recently, by the Chernobyl accident. Engineered extraction of 137Cs from soils and groundwaters is exceedingly difficult. Because the half life of 137Cs is only 30.2 years, remediation might be more effective (and less costly) if 137Cs bioavailability could be demonstrably limited for even a few decades by use of a reactive barrier. Essentially permanent isolation must be demonstrated in those few settings where high nuclear level wastes contaminated the environment with 135Cs (half life 2.3x106 years) in addition to 137Cs. Clays are potentially a low-cost barrier to Cs movement, though their long-term effectiveness remains untested. To identify optimal clays for Cs retention Cs resorption was measured for five common clays: Wyoming Montmorillonite (SWy-1), Georgia Kaolinites (KGa-1 and KGa-2), Fithian Illite (F-Ill), and K-Metabentonite (K-Mbt). Exchange sites were pre-saturated with 0.16 M CsCl for 14 days and readily exchangeable Cs was removed by a series of LiNO3 and LiCl washes. Washed clay were then placed into dialysis bags and the Cs release to the deionized water outside the bags measured. Release rates from 75 to 139 days for SWy-1, K-Mbt and F- 111 were similar; 0.017 to 0.021% sorbed Cs released per day. Both kaolinites released Cs more rapidly (0.12 to 0.05% of the sorbed Cs per day). In a second set of experiments, clays were doped for 110 days and subjected to an extreme and prolonged rinsing process. All the clays exhibited some capacity for irreversible Cs uptake so most soils have some limited ability to act as a natural barrier to Cs migration. However, the residual loading was greatest on K-Mbt (∼ 0.33 wt% Cs). Thus, this clay would be the optimal material for constructing artificial reactive barriers

  8. Determination of Corrections in the Absolute Measurement of 137Cs

    A method, of determining corrections in absolute measurements of 137Cs by 4π proportional counter is described. The correction for self-absorption of 137Cs beta particles from sources formed by vacuum deposition of CsCl on standard carrier films was determined. These samples, which had negligible self-absorption, were measured by 4π counter. The radioactive substance on the film was then dissolved, and by the addition of carrier was converted to a form similar to that of sources usually used for absolute measurement. The correction determined for self-absorption was higher than the value expected from comparison with other radionuclides having near Eβmax. The correction for internal conversion coefficient and gamma efficiency of the beta detector was determined with 137mBa samples. Barium was separated as BaSO4 precipitate and deposited on a standard carrier film used for absolute measurement with a layer thickness of about 1 mg/cm2. These samples were simultaneously measured by means of a 4π beta proportional counter and a Nal(Tl) scintillation counter. From corresponding counting rates in both counters, and from both known efficiencies, the value for a correction appropriate to one disintegration of 137mBa was calculated. The values measured were used further for computation of the internal conversion coefficient and the half-life of 137'mBa, which was ascertained to be 155 ± 3 s. (author)

  9. 131I-activity in man's thyroid and 137Cs-activity in muscle tissue

    131I- and 137Cs-activities in milk and salad on one hand, and in thyroid - and muscle tissues of deceased persons on the other hand were determined in the days and weeks after the Chernobyl accident around Graz, Austria. The values listed in the tables are intended to investigate radionuclides migration from the food chain to human tissues. 4 tabs. (qui)

  10. 90Sr and 137Cs determination in milk and foodstuff samples in North and Middle Moravia

    Activities of radionuclides Sr-90 and Cs-137 in milk and parts of foodstuff have been determined in National Radiation Protection Institute for many years. Sr-90 activity in those samples determinate branch Ostrava by radiochemical procedure - precipitation with oxalic acid and measuring with using gas-flow proportional detector. Gamma spectrometry with HPGe detector is using for 137 Cs determination. (authors)

  11. 137Cs deposition in peat profiles on a raised bog in central Sweden; Forests ecosystems

    Rosen, K.; Vinichuk, M.; Galan, P.R.; Johanson, K.J. (Swedish Univ. of Agricultural Sciences, Dept. of Soil Sciences, Uppsala (Sweden))

    2009-06-15

    Distribution of 137Cs depositions within peat profiles in open bog and nearby (low pine) sites in raised bog are shown and discussed. A possible involvement of Sphagnum moss in radionuclide binding and retention in such nutrient poor ecosystem is suggested. (au)

  12. Specific activity and concentration model applied to 137Cs movement in a eutrophic lake

    A linear systems-analysis model which simulates time-dependent dynamics of specific activity and concentration of radiocesium in lake ecosystems was applied to a shallow, eutrophic lake that had received a pulse input of 137Cs. Best estimates of transfer coefficients for abiotic compartments (sediment, interstitial water and lake water) and the macrophyte compartment which controlled the mass balance of cesium in water were determined by ''tuning'' our initial estimates of the transfer coefficients to observed data on 137Cs concentrations and contents of these compartments. In most cases, the optimized transfer coefficients for the abiotic compartments were not greatly different from our independently derived initial estimates, and the simulations for optimized coefficients were close to those based on initial estimates. The 137Cs concentrations in water as predicted by the optimized transfer coefficients were then used to calculate 137Cs kinetics in biota other than macrophytes. In general, model simulations were close to concentrations observed in the biota. The agreement between 137Cs concentrations and simulations in bottom invertebrates supported our assumption that bottom sediments are not a major source of Cs to the biota. Our specific activity and concentration model was compared to the radionuclide content model, the model used in terrestrial ecosystems. For biotic components of aquatic ecosystems, values of α/sub ij/, the transfer coefficients of our model, are easily estimated from turnover rates of radiocesium in individual organisms in the laboratory

  13. Assessment of the transfer of 137Cs in three types of vegetables consumed in Hong Kong

    A dynamic food chain model has been built for the modeling of the transfer of 137Cs in three types of vegetables consumed in Hong Kong, namely, white flowering cabbage (Brassica chinensis), head lettuce (Lactuca sativa) and celery (Apium graveolens). Some parameters have been estimated from the experimental data obtained in this work. The experimental data include the transfer factors of 137Cs from soil to the different vegetable species which are determined through high resolution gamma spectrometry, maximum crop biomasses for the vegetable species, the dry-to-fresh ratios for the vegetable species, the bulk density of soil layers and the average concentration of 137Cs in air. The derived parameters include the deposition rate and the root uptake rate, information for tillage, the logistic growth model and radionuclide concentrations in vegetables. The dynamic food chain model is solved by the Birchall-James algorithm to give the 137Cs concentration in subsurface soil, from the 0.1-25 cm soil layer, and the 137Cs concentration in harvested and unwashed vegetables. As validation of the model and parameters, the concentrations obtained experimentally and from the model are compared and are found to be in good agreement

  14. 137Cs availability for soil to understory transfer in different types of forest ecosystems

    A quantitative analysis of 137Cs bioavailability in forest soils in the long term after the Chernobyl NPP accident based on a 3-year (1996-1998) investigation is presented. Five forest sites with different trees, composition and properties of soil were studied to identify factors determining radiocaesium transfer to different understory species. The following parameters were investigated: 137Cs activity concentrations and its speciation in various horizons of forest soil, accumulation of this radionuclide by different species of understory vegetation and distribution of root biomass in the soil profile. It has been shown that one decade after the deposition maximum 137Cs activity in soil of the experimental sites considered is located in different soil layers dependent on moisture regime, characteristics of litter and soil properties. A linear dependence between aggregated transfer factors for different species and groups of species of understory vegetation and exchangeable and available fractions of radiocaesium in soil was found. The vertical distribution of 137Cs activity, percentage of exchangeable radiocaesium in each horizon of litter and soil, as well as distribution of root systems (mycelia) over the soil profile are key factors governing variations in the availability of 137Cs for transfer to all forest understory components

  15. Migration of 137Cs in the soil of sloping semi-natural ecosystems in Northern Greece

    In the present study, the 137Cs concentration in the soil of sloping semi-natural ecosystems at four different regions of Western Macedonia in Greece was measured 10 years after the Chernobyl accident. These regions were highly polluted due to the deposition of radionuclides escaped during the accident. The concentrations of 137Cs measured were found to differ significantly among the four regions. The rates of both horizontal and vertical migration in the soil were also evaluated. The vertical migration velocity of 137Cs was found to range from 0.1 to 0.3 cm per year, in the most contaminated areas. Consequently, 10 years following the Chernobyl accident, the bulk of 137Cs deposited over the surface of the studied areas in Greece was found to be restricted in the upper 5 cm layer of soil. Regarding the horizontal migration, in most of the sampling sites, we did not detect any displacement or trend to movement of radiocaesium on the surface from the upper to the lower levels of the slopes. Instead, we recorded decreased concentrations of 137Cs with the decrease of altitude

  16. 137Cs contamination of the Techa river flood plain near the village of Muslumovo

    The results of a radiometric survey of the Techa river flood plain near the village of Muslumovo in the Chelyabinsk region of Russia are presented. The observed territory extended 16.6 km along the riverbed, with a total area of 2.5 km2. The collimated scintillation detector technique was applied to in situ field measurements of 137Cs deposition on the soil. Maps of 137Cs deposition and soil penetration depth were developed on the basis of approximately 5000 measurements. The total 137Cs deposition within the surveyed territory has been estimated at 6.6 TBq. The means of the total 137Cs soil depositions at half-kilometer sites on the flood plain and its distribution along the river have also been calculated. A maximum 137Cs contamination above 7.5 MBq/m2 is associated with a bank height up to 1 m above the usual water level. The data identify zones of intensive radionuclide sedimentation and transit zones

  17. Peculiarities of 137Cs accumulation by macromycetes in dry bors of Ukrainian Polessye

    The main ecological peculiarities of dry bor in Ukrainian Polessye were given. Research were carried out in Central Polessie of Ukraine during 1997 - 1999. Results were obtained due to spectrometric measurement of specific activity of 137Cs in fruit bodies of mushrooms and in the soil. Species composition of macromycetes was divided on homogeneous groups on intensity of 137Cs accumulation. Amanita porphyria, A. muscaria and Tricholoma portentosum belong to the group of weak 137Cs accumulation from the soil (TF = 15 - 20); Amanita pantherina, A. phalloides, Cantharellus cibarius, Boletus edulis, Tricholoma flavovirens and Laccaria laccata - to the group of moderate radionuclide accumulation (TF = 30 - 55). The group of strong 137Cs accumulation (TF = 100 - 180) consists of Suillus variegates, S. bovines and Hydnum imbricatum; and group of very strong accumulation (TF 200 - 280) - of Xerocomus badius, Lactarius rufus, Russula xerampelina, Cortinarius varius and Paxillus involutus. Cortinarius sanguineus (with TF 400) is an accumulator of 137 Cs. Comparative evaluation of dry bor was given from the point of view of purchase of edible macromycetes in it

  18. Radioactivity in the Exclusive Economic Zone of east coast Peninsular Malaysia. Distribution trends of 137Cs in surface seawater

    Large volumes of surface seawater samples were collected from thirty locations in the Exclusive Economic Zone (EEZ) of the east coast Peninsular Malaysia on June 2008 to study the activity concentrations of 137Cs. The results will serve as additional information to the existing baseline data and is very useful for monitoring fresh input of anthropogenic radionuclide into Malaysian marine environment. In this study, the activity concentrations of 137Cs were determined using co-precipitation technique, followed by Gamma Spectrometry measurement. The mean activity concentration of 137Cs ranged between 3.40 and 5.89 Bq/m3. Higher activity concentrations were observed at the coastal and towards the south of Peninsular Malaysia and were aligned with the high turbidity. These may due to the rapid diffusion of 137Cs from suspended particulates and fine sediments into surface seawater. The activity concentrations of 137Cs observed in this study were slightly higher than the concentrations reported in seawater at the Straits of Malacca, Vietnam and Philippines. This might be because the study area received more input of 137Cs that originated from global fallout and then deposited on land which later being transported subsequently into the coastal zone due to siltation and erosion processes. It could also be attributed to the intrusion of river waters containing higher concentrations of 137Cs. (author)

  19. Association of fallout-derived 137Cs,90Sr and 239,240Pu with natural organic substances in soils

    Activity concentrations and associations of fallout-derived Cs, Sr and Pu in soils were investigated. The activity concentrations of 137Cs, 90Sr and 239,240Pu in volcanic ash soil were much higher than those in granite soil. They decreased with increasing depth in the soil. The activity ratios of 239,240Pu/137Cs and 90Sr/137Cs tended to increase slightly with increasing soil depth. Alkali extraction experiments with 0.1 M NaOH solution showed that the percentage activities of the fallout radionuclides found in the organic acid fractions were in the order 239,240Pu>90Sr>137Cs. The concentrations of 137Cs and 239,240Pu reacted with humic fractions were higher than those with fulvic fractions. In contrast to 137Cs and 239,240Pu,90Sr reacted more with fulvic fractions than with humic fractions. These results provide information about the effects of organic substances on the retention and migration of 137Cs,90Sr and 239,240Pu in soils under natural conditions

  20. Levels of 137Cs and 40K in edible parts of some vegetables consumed in Egypt

    The concentrations of 137Cs and 40K in some Egyptian foodstuffs have been measured. The results of this study can be considered as a first step towards calculating the baseline levels of radioactivity in foodstuffs in Egypt. Furthermore, the data presented herein can be used as a reference level for future food radioactivity monitoring after the possible operation of the planned nuclear power plants, as well as to screen imported foodstuffs that are suspected of being contaminated. The overall intake of 137Cs is quite low and no significant radionuclide contamination was found. The highest contents of 137Cs and 40K among the tested foodstuffs were in Jew's mallow and roquette. Calculations were also made to determine the potential dose to an individual consuming vegetables

  1. Chronology of sedimentation in Cienfuegos bay, elucidated from 210Pb and 137Cs

    This article present the results of the use of radiotracers in geochronology technique for evaluate the anthropogenic impact on Cienfuegos Bay, Cuba. The excess 210Pb and 137Cs radionuclides were measurements on one sediment corer collected in Cienfuegos Bay using a gravity core. Each core was sliced and pre treatment for gamma spectrometric measurements and other complementary analyses. It was applied the Constant Rate Supply model for dating the 210Pb profile and it was used the 137Cs as an alternative method for dating calibration. The results show a good agreement between CRS method's results and 1963's 137Cs peak. Spatial and temporal evaluation of the radiotracers profiles have shown that sedimentation rate have changed in the last fourth years and it is associated to the economical and industrial development. It was demonstrated the significance of radiotracers in environmental impact on estuaries and semi enclosed bays

  2. Modelling of 137Cs behaviour in forest ecosystems and prediction of its accumulation in forest products

    A mathematical model of 137Cs migration in forest ecosystem contaminated due to the Chernobyl accident presented, which describes the behaviour of this radionuclide in the forest litter-soil system, tress, and forest animals. The model's parameters for different types of forest ecosystems are estimated and model's adequacy is tested through the use of independent experimental data. The sensitivity of the model's output variables is analyzed to variations in the most significant parameters. The differences in the seasonal and mean annual dynamics of 137Cs concentration in muscles of roe deers and mooses are shown to be defined by specific features of the diets of these animals and variations in 137Cs content in the main diet components

  3. The effects of gamma irradiation on leaching of 137Cs from organic matrix wasteforms

    The effects of γ-irradiation on the leaching behaviour of 137Cs in organic matrix wasteforms has been studied. The matrix materials used include epoxide, polyester and vinyl ester thermosetting resins and bitumen. Leaching of 137Cs in such matrices can be described by models, based on diffusion, which take into consideration such factors as non-representative surface layers, finite sample size, and sorption effects. In many cases, the changes observed on irradiation arise from modification of the sorptive capacity of the wasteform for 137Cs, producing changes in the experimentally observed diffusion coefficients. In samples containing wet wastes, enhanced leaching in the first few days is observed after irradiation. This arises from loss of water from the sample surfaces during irradiation producing an enhanced concentration of the radionuclide in the surface. (author)

  4. Deposition, transfer and migration of 137Cs and 90Sr in Swedish agricultural environments, and use of 137Cs for erosion studies

    Intensive atmospheric tests of nuclear bombs in the late 1950s and early 1960s resulted in fallout on Sweden of 3 kBq/m2137Cs and 2 kBq/m290Sr. To determine how soil characteristics influence radionuclide transfer to red clover, pot experiments with 137Cs and 90Sr were made with 178 Swedish mineral soils; significant negative correlations were obtained the with levels of P, K and Ca. To quantify impact in field conditions, experiments with artificial depositions on microplots were started in 1961. Transfer to barley on 12 topsoils combined with sandy and clay subsoils, and to grass on two contrasting pastures, was followed over two decades. The subsoil type was found to be important. Fallout of 137Cs from the Chernobyl accident, up to 200 kBq/m2 in some areas of Sweden, was studied between 1986 and 1994. As in the microplot experiments, transfer of 137Cs to grass was higher than to arable crops. Transfer rates were high in the first year(s), and then decreased differently from year to year, as shown by a new Tar (i.e. annual reduction rate in nuclide transfer) concept. The use of Chernobyl fallout to investigate soil redistribution on arable fields is briefly discussed; a frame-scrape soil-sampling procedure is proposed to improve the accuracy and precision of the 137Cs technique for evaluation of soil erosion. (author)

  5. Influence of biologically-active substances on 137Cs and heavy metals uptake by Barley plant

    Available in abstract form only. Full text of publication follows: When solving the problem of contaminated agricultural lands rehabilitation, most of attention is concentrated on the effective means which allow the obtaining of ecologically safe production. The minimization of radionuclides and heavy metals (HM) content in farm products on the basis of their migration characteristics in agro-landscapes and with the regard for different factors influencing contaminants behavior in the soil-plant system is of great significance. Our investigation has shown that the effect of biologically active substances (BAS) using for seeds treatment on 137Cs transfer to barley grown on Cd contaminated soil was dependent on their properties and dosage, characteristics of soil contamination and biological peculiarities of plants, including stage of plants development. Seeds treatment by plant growth regulator Zircon resulted in a significant increase in 137Cs activity in harvest (40- 50%), increase in K concentration and significant reduction in Ca concentration. Increased Cd content in soil reduced 137Cs transfer to barley plants by 30-60% (p137Cs uptake by roots and Cd and Pb phyto-toxicity. The experimental data do not make it possible to link the BAS effect on inhibition of 137Cs absorption by plants directly with their influence on HM phyto-toxicity. The dependence of Concentration Ratio of 137Cs on the Ambiol and El dose was not proportional and the most significant decrease in the radionuclide uptake by plants was reported with the use of dose showing the most pronounced stimulating effect on the barley growth and development. The pre-sowing seed treatment with Ambiol increased Pb absorption by 35-50% and, on the contrary, decreased Cd uptake by plants by 30-40%. (authors)

  6. 137Cs, 239,240Pu and 241Am in boreal forest soil and their transfer into wild mushrooms and berries

    Profiles of podzolic soil from boreal forests were sampled from eight sites in Finland and the distribution of 137Cs in the soil layers was determined. In addition, 239,240Pu and 241Am were determined from two soil profiles taken at one sampling site. Inventories of 137Cs in the soil profiles varied between 1.7 kBq/m2 and 42 kBq/m2, reflecting known variation in 137Cs fallout from the Chernobyl accident. The highest proportions of the radionuclides were found in the organic layer at a depth of less than 5 cm, which on average contained 47% of 137Cs, 76% of 239,240Pu and 79% of 241Am. In the litter, clearly higher proportions of 137Cs were found compared to 239,240Pu and 241Am, probably indicating its more effective recycling from the organic layer back to the surface. Only very minor proportions of 137Cs were recorded below 20 cm. The concentration of 137Cs in the soil profiles could be approximated with a declining logarithmic trend. The activity concentrations of 137Cs were determined for six wild mushroom species and three wild berry species at two sites, as well as the aggregated transfer factors and the distribution of 137Cs between their various parts. In addition, 239,240Pu and 241Am were determined in one mushroom and three berry species at one site. Very high concentrations of 137Cs, up to 20 kBq/kg (d.w.), were found in mushrooms, and their transfer factors were between 0.1 m2/kg and 1.0 m2/kg. In berries, the transfer factors were an order of magnitude lower. 137Cs accumulated more in the caps of mushrooms and in the fruits of berries than in other parts. Transfer factors for 239,240Pu and 241Am were two to three orders of magnitude lower than those of 137Cs. - Highlights: ► 137Cs, 239,240Pu and 241Am mainly concentrated in organic layer in podzolic soil. ► Distribution of 137Cs in the upper 20 cm soil follows exponential declining trend. ► 137Cs concentrates into mushrooms but varies considerably between species. ► 137Cs concentrates in mushroom

  7. Inoculation with arbuscular mycorrhizae does not improve 137Cs uptake in crops grown in the Chernobyl region

    Methods for cleaning up radioactive contaminated soils are urgently needed. In this study we investigated whether the use of arbuscular mycorrhizal (AM) fungi can improve 137Cs uptake by crops. Barley, cucumber, perennial ryegrass, and sunflower were inoculated with AM fungi and grown in low-level radionuclide contaminated soils in a field experiment 70 km southwest of Chernobyl, Ukraine, during two successive years (2009–2010). Roots of barley, cucumber and sunflower plants were slightly or moderately infected with AM fungus and root infection frequency was negatively or non-correlated with 137Cs uptake by plants. Roots of ryegrass were moderately infected with AM fungus and infection frequency was moderately correlated with 137Cs uptake by ryegrass. The application of AM fungi to soil in situ did not enhance radionuclide plant uptake or biomass. The responsiveness of host plants and AM fungus combination to 137Cs uptake varied depending on the soil, although mycorrhization of soil in the field was conditional and did not facilitate the uptake of radiocesium. The total amount of 137Cs uptake by plants growing on inoculated soil was equal to amounts in plant cultivated on non-inoculated soil. Thus, the use of AM fungi in situ for bioremediation of soil contaminated with a low concentration of 137Cs could not be recommended. -- Highlights: • Effect of mycorrhization on 137Cs uptake by crops was studied in a field experiment. • AM fungi did not enhance radionuclide plant uptake or biomass. • Plants growing on inoculated and non-inoculated soil accumulate 137Cs equally

  8. Modelling of {sup 137}Cs behaviour in the soil-plant system following the application of ameliorants

    Spiridonov, S.; Fesenko, S.; Sanzharova, N. [Russian Institute of Agricultural Radiology and Agroecology, Obninsk (Russian Federation)

    2004-07-01

    A set of countermeasures aimed at reducing {sup 137}Cs uptake by plant products includes agrochemical measures based on changes in the soil properties after the application of ameliorants. The dynamic models for studying the effect of the application of potassium fertilizers and dolomite powder on {sup 137}Cs accumulation in plants are presented. Conceptual approaches to the development of models are based on the identification of mechanisms governing a complex of physico-chemical processes in soil after the use of ameliorants. The following assumptions were used in the development of models: - dynamics of {sup 137}Cs distribution in each soil layer depends on the sorption processes characterized by different time to achieve quasi-equilibrium (exchangeable uptake and fixation by clay minerals) as well as on vertical migration process; - change in {sup 137}Cs content in soil solution results from the radionuclide sorption on selective and nonselective exchange sites; - uptake of extra amounts of K{sup +} and Ca{sup 2+} in soil solution produces effect on processes of {sup 137}Cs exchangeable sorption and initiate specific processes responsible for {sup 137}Cs fixation in the crystal lattice of clay minerals; - Ca{sup 2+} and K{sup +} cations have a competing effect on {sup 137}Cs uptake by plants from soil solution, which along with the fixation processes, causes lower accumulation of this radionuclide by plants during the application of ameliorants. The developed models were parameterized for soils of the coniferous forest located in the Bryansk region in area suffered from the radioactive fallout after the Chernobyl accident. Effects of ameliorants and time of their application on {sup 137}Cs behaviour in the soil-plant system are assessed. The contribution of soil chemical and biological processes to the decrease in the radionuclide uptake by plants is estimated. (author)

  9. Separation of 137Cs from nuclear waste

    Sodium zirconate is one member of a family of new inorganic ion exchange materials which have high affinity for all actinides and fission product cations except for Cs+. A combination of cold, tracer and high level liquid waste experiments with sodium zirconate has shown that 70 to 80 and 80 to 100% of the Cs+ in high level liquid waste remains in solution following batch or column equilibration, respectively. The fact that 137Cs can be obtained in relatively pure form permits subsequent conversion directly to an insoluble radiation source. This is of prime importance in areas such as sewage sludge sterilization via γ-ray irradiation. (author)

  10. Transfer Factors of 137Cs and 85Sr by Freshwater Fish in Tropical Environment

    The experiment was set up to determine the radionuclide transfer factors (T.F.) of 137Cs and 85Sr by tropical freshwater fish. Mixed breeding catfish between Thai catfish (Clarias acrocephalus) and African catfish (Clarias garispinus African sharptooth) were exposed to 137Cs and 85Sr in two 1000-L tanks for 42 days during uptake phase. The calculated T.F. at equilibrium, in flesh, bone, skin plus fin and head were 3.2, 2.6, 1.6 and 1.5 L.kg-1 for 137Cs and 0.1, 4, 1 and 17 L.kg-1 for 90Sr, respectively. These results revealed a much lower values than reported elsewhere for temperate environment, however were in accordance with the tropical values as observed by others. The biological half-lives of 137Cs and 85Sr in flesh part were 41 and 4 days respectively. It is then imperative that suitable T.F. values are employed in the models to predict the transport of radionuclides within the particular ecosystem and the potential dose to man. Thus the relationship between routine release of radionuclides and resulting dose to man can be established and corresponding release limits stipulated for that particular nuclear site

  11. Ecological half-times of 137Cs and 90Sr in dairy milk in regions with different soil types

    Long-lived radionuclides 137Cs and 90Sr have been regularly monitored since the 1960's in dairy milk in Finland. The aim of this work was to study regional differences in long-term behaviour of 137Cs and 90Sr in dairy milk including the nuclear weapons tests period and the period after the Chernobyl fallout. In the milk production areas soil types vary from clayish to organic soils. Although total 137Cs deposition from nuclear weapon testings was about the same in all regions, 137Cs concentrations in dairy milk during the 1960's ranged between 5 and 35 Bq/l being highest in regions with high proportion of peat soils. The uneven deposition after the Chernobyl accident before the start of the growing season gave rise to 137Cs concentrations in dairy milk ranging from 3 Bq/l to 60 Bq/l. The ecological half-times were estimated for the decrease of 137Cs and 90Sr after the end of nuclear weapon tests period and the Chernobyl fallout for short and longer time intervals. In the milk production areas dominated by organic soils the ecological half-times for decrease of 137Cs were twice as long as in the regions with clayish soils. Half-times of 90Sr for longer time intervals were considerably longer than those for 137Cs. This long-term data on behaviour of 137Cs and 90Sr in dairy milk can be utilized in testing food chain models. The incorporation of region specific parameters in models will enhance their usefulness in case of a nuclear accident. (author)

  12. 137Cs leaching through cement-radwaste matrix

    To assess the safety for disposal of radioactive mortar-waste composition, the leaching of 137Cs from a waste composite into a surrounding fluid has been studied. Leaching tests were carried out in accordance with a method recommended by IAEA. Determination of retardation factors, KF and coefficients of distribution, kd, using a simplified mathematical model for analyzing the migration of radionuclides, has been developed. In our experiment we have achieved the lowest leaching values after 120, days for each samples. Results presented in this paper are examples of results obtained in a 30 year mortar and concrete testing project, which will influence the design of the engineered trenches system for a future central Serbian radioactive waste storage center. (author)

  13. 137Cs penetration through concrete in radioactive waste management

    To assess the safety for disposal of radioactive waste-concrete composition, the leaching of 137Cs from a waste composite into a surrounding fluid has been studied. Leaching tests were carried out in accordance with a method recommended by IAEA. Determination of retardation factors, KF and coefficients of distribution, kd, using a simplified mathematical model for analyzing the migration of radionuclides, has been developed. In our experiment we have achieved the lowest leaching values after 60 days in samples. Results presented in this paper are examples of results obtained in a 20 year mortar and concrete testing project, which will influence the design of the engineered trenches system for a future central Serbian radioactive waste storage center. (author)

  14. Recent 137Cs deposition in sediments of Admiralty Bay, Antarctica

    Cesium-137, radium-226 and lead-210 profiles of a 25 cm sediment core give an indication of recent changes in land-ocean interactions at a polar coastal environment (Admiralty Bay, King George Island, Antarctica). The linear sedimentation accumulation rate at the study site calculated from the unsupported 210Pb profile was 6.7 mm/year from 1965 to 2005. A 3.5-fold increase in 137Cs concentrations was observed in the top layer of this sediment core. This sharp increase seems to indicate a recent redistribution of fallout radionuclides previously deposited on soil, vegetation and snow. These results imply enhanced land-ocean interactions at this site likely as a result of climate change. Because our results are based on a single core, additional investigations are needed to confirm our observations.

  15. The effective and environmental half-life of 137Cs at Coral Islands at the former US nuclear test site

    The United States (US) conducted nuclear weapons testing from 1946 to 1958 at Bikini and Enewetak Atolls in the northern Marshall Islands. Based on previous detailed dose assessments for Bikini, Enewetak, Rongelap, and Utirik Atolls over a period of 28 years, cesium-137 (137Cs) at Bikini Atoll contributes about 85-89% of the total estimated dose through the terrestrial food chain as a result of uptake of 137Cs by food crops. The estimated integral 30, 50, and 70-year doses were based on the radiological decay of 137Cs (30-year half-life) and other radionuclides. However, there is a continuing inventory of 137Cs and 90Sr in the fresh water portion of the groundwater at all contaminated atolls even though the turnover rate of the fresh groundwater is about 5 years. This is evidence that a portion of the soluble fraction of 137Cs and 90Sr inventory in the soil is lost by transport to groundwater when rainfall is heavy enough to cause recharge of the lens, resulting in loss of 137Cs from the soil column and root zone of the plants. This loss is in addition to that caused by radioactive decay. The effective rate of loss was determined by two methods: (1) indirectly, from time-dependent studies of the 137Cs concentration in leaves of Pisonia grandis, Guettarda specosia, Tournefortia argentea (also called Messerschmidia), Scaevola taccada, and fruit from Pandanus and coconut trees (Cocos nucifera L.), and (2) more directly, by evaluating the 137Cs/90Sr ratios at Bikini Atoll. The mean (and its lower and upper 95% confidence limits) for effective half-life and for environmental-loss half-life (ELH) based on all the trees studied on Rongelap, Bikini, and Enewetak Atolls are 8.5 years (8.0 years, 9.8 years), and 12 years (11 years, 15 years), respectively. The ELH based on the 137Cs/90Sr ratios in soil in 1987 relative to the137Cs/90Sr ratios at the time of deposition in 1954 is less than 17 years. The magnitude of the decrease below 17 years depends on the ELH for 90Sr that

  16. The effective and environmental half-life of 137Cs at Coral Islands at the former US nuclear test site.

    Robison, William L; Conrado, Cynthia L; Bogen, Kenneth T; Stoker, A Carol

    2003-01-01

    The United States (US) conducted nuclear weapons testing from 1946 to 1958 at Bikini and Enewetak Atolls in the northern Marshall Islands. Based on previous detailed dose assessments for Bikini, Enewetak, Rongelap, and Utirik Atolls over a period of 28 years, cesium-137 (137Cs) at Bikini Atoll contributes about 85-89% of the total estimated dose through the terrestrial food chain as a result of uptake of 137Cs by food crops. The estimated integral 30, 50, and 70-year doses were based on the radiological decay of 137Cs (30-year half-life) and other radionuclides. However, there is a continuing inventory of 137Cs and 90Sr in the fresh water portion of the groundwater at all contaminated atolls even though the turnover rate of the fresh groundwater is about 5 years. This is evidence that a portion of the soluble fraction of 137Cs and 90Sr inventory in the soil is lost by transport to groundwater when rainfall is heavy enough to cause recharge of the lens, resulting in loss of 137Cs from the soil column and root zone of the plants. This loss is in addition to that caused by radioactive decay. The effective rate of loss was determined by two methods: (1) indirectly, from time-dependent studies of the 137Cs concentration in leaves of Pisonia grandis, Guettarda specosia, Tournefortia argentea (also called Messerschmidia), Scaevola taccada, and fruit from Pandanus and coconut trees (Cocos nucifera L.), and (2) more directly, by evaluating the 137Cs/90Sr ratios at Bikini Atoll. The mean (and its lower and upper 95% confidence limits) for effective half-life and for environmental-loss half-life (ELH) based on all the trees studied on Rongelap, Bikini, and Enewetak Atolls are 8.5 years (8.0 years, 9.8 years), and 12 years (11 years, 15 years), respectively. The ELH based on the 137Cs/90Sr ratios in soil in 1987 relative to the 137Cs/90Sr ratios at the time of deposition in 1954 is less than 17 years. The magnitude of the decrease below 17 years depends on the ELH for 90Sr

  17. Assessment of the mobility and bioavailability of 60 Co and 137 Cs in contaminated soils

    Results of a classical sequential chemical extraction procedure for 137 Cs in an acid Oxisol showed that after 3 years of contamination radiocesium remains potentially available for transfer processes: 40% bio-available, 20% mobile under oxidizing conditions and 40% bound to Fe and Mn oxides (available under reducing conditions). At this time, the transfer factor obtained in this soil was higher than values obtained in basic Oxisol and was higher than values obtained in soils from temperate climate areas. Seven years after the contamination, the 137 Cs distribution in this acid Oxisol have been changed as consequence of changes in soil properties: 8% bioavailable, 16% mobile under oxidizing conditions, 43% bound to Fe and Mn oxides and 33% strongly bound to soil compounds. Changes in the 137 Cs distribution in this soil were followed by reductions in soil to plant transfer factor. Between 1996 and 2000, the 137 Cs distribution, 137 Cs soil to plant transfer factor and soil properties in the basic Oxisol remained almost the same. The 60 Co distribution showed that Mn oxides is the main sink for this element and four years after contamination no 60 Co was detected as bioavailable or detectable in plants. In this study the use of an alternative sequential chemical extraction protocol to evaluate 60 Co and 137 Cs mobility under a large range of physico-chemical soil properties has shown to be very consistent with soil to plant transfer factors data for maize. The knowledge of bio-geochemical behavior of radionuclides in soil system can be used for the risk assessment in the case of nuclear accident or contamination scenarios. (author)

  18. Studies on bioaccumulation of 152Eu, 137Cs, 60Co by different algal genera

    In the present paper, the bioaccumulation of a mixture of potentially hazardous, long lived radionuclides 152Eu, 137Cs and 60Co by five algal genera of three different family, viz.: Lyngbya and Phormidium from cyanophyceae; Phizoclonium and Chaetomorpha from chlorophyceae and Catenella from rhodophyceae have been studied. Because of the long half life and high solubility, these radionuclides are considered the most hazardous in the nuclear spent fuel

  19. Predicting transfers of 137Cs in terrestrial and aquatic environments: a whole-ecosystem approach

    Smith, Jim; Cross, M.; Wright, S M

    2002-01-01

    lt is well known that during the years after a nuclear accident the bioavailability and environmental mobility of radionuclides may change significantly, resulting in significant changes in contamination of foodstuffs and surface waters. Studies on 137Cs and, to a lesser extent, 90Sr, have quantified these changes in some ecosystems. However, variability in temporal changes of these radionuclides in aquatic and terrestrial systems is not yet well quantified. Estimation of such variability is ...

  20. Fallout 137Cs in soils from North Western Libya

    Fallout levels of 137Cs in surface soil from North Western Libya have been measured using gamma-ray spectrometry. The activity concentrations of 137Cs in soil ranged from 975 to 1720 mBq x kg-1. The areal activity concentrations ranged from 1300 to 2250 mBq x m-2, and were highly correlated with annual precipitation. The effective dose from external exposure to 137Cs is found to be 3 nSv x y-1. (author)

  1. Distribution of 137Cs, 40K, 238U and 232Th in soils from Northern Venezuela

    More than one hundred undisturbed soil samples form Northern Venezuela and the islands of Margarita and Los Roques have been analyzed for 137Cs, 40K, 238U and 232Th by γ-ray spectroscopy. The specimens were taken from between 5-10 cm below the earth's surface. Thus, they are valid not only for the 137Cs deposition studies but also for the estimation of the natural γ-ray dose from primordial radionuclides that form the terrestrial component. The concentrations of 40K was directly determined from its 1461 keV γ-ray, while those of 137Cs, 238U and 232Th were performed using a γ-ray from one of their daughter radionuclides: the 661 keV γ-ray of 137mBa for 137Cs, the 1760 keV γ-ray of 214Bi for 238U and the 2620 keV γ-ray of 208Tl for 232Th. Finally, the concentration values were compared with those of global estimates. (author) 15 refs.; 4 figs.; 2 tabs

  2. 137Cs activity and associated dose in the coastal marine environment of India

    Coastal marine environment is important for India since a considerable percentage of the human population resides in coastal areas. Fallout radionuclides as well as non-radioactive substances have polluted the coastal marine environment of India. The introduction of 137Cs, a fallout radionuclide, considered as global pollutant, into marine environment has created the need for marine environmental data. The main objective is to provide data on the present level of 137Cs which is important from the standpoint of radiological health and dose associated with it. Such database will also provide benchmark which will be helpful in assessing the impact of additional contribution to marine radioactivity in the future. The results confirm that the mean annual individual dose from 137Cs in seafood (fish) for the Indian subcontinent is 0.03 μSv. The highest annual individual dose for 137Cs due to the ingestion offish is in the age group of 40 to 59 years which is due to the reason that the Indian annual dietary intake of fish is highest in this age group

  3. Stress modification of the kinetic of 137Cs absorption and primary pattern of intercompartments distribution

    The kinetic of 137Cs absorption by pea seedlings and the possibility of alteration of the qualitative and quantitative characteristics of this process were investigated. Gamma irradiation of dry seeds of pea at doses of 25-50 Gy brings about a global change in the kinetic and concentration curves of the active and passive 137Cs uptake by the plant roots. The first and second phases of the kinetic curve, which mirror the passive stage of absorption, and the type of the concentration curve in general, were changed. The level of radionuclide accumulation at this passive stage and the retention for the apoplast-symplast passage increase significantly. Changes in the Michaelis-Menten parameters of the concentration curves were also observed. The changes mirror changes in the radionuclide distribution in the symplast-apoplast system. The time of 137Cs retention for the root-stem transition increased from 0.5 min to 1 min. This investigation suggests that the cation exchange capacity of the parts and structures of a plant is among the main factors which determine the primary intercompartment distribution of 137Cs as nonbiogenous mineral elements

  4. On the 137Cs bioavailability for the soil-plant transfer in soil treated with fertilizers

    One of the most used agricultural countermeasures to reduce the uptake of adionuclides from soil into plants is the chemical treatment of the soil with fertilizers. The speciation of radionuclides in contaminated soils allows to assess the mechanisms governing the migration of radionuclide and their bioavailability. The paper presents the results of a laboratory experiment on the influence of several potassium fertilizers on the distribution of 137Cs in the soil fractions that are readily available for the uptake into the plant. By the sequential extraction method, the distribution of 137Cs has been determined in the water soluble and exchangeable fractions separated at the first moment of contamination. Most of the 137Cs has been bounded in the forms with a low accessibility to the plant, the differences in the distribution depending on the soils characteristics. Fertilizers releasing fast the potassium ions into the soil solution reduced the 137Cs concentration in the readily available fractions, whereas no modification has been produced by the application of adularia fertilizer. (author)

  5. Speciation of 137Cs in the Baltic sea water

    A possibility of application of Filtrac 391 and Nuclepore filters, Ky-2-8-C exchanger and the Mtilon-T fiber impregnated with Fe, Co, Ni ferrocyanides for separation of particulate and ionic 137Cs in the sea water was investigated. Physico-chemical forms of 137Cs were investigated in the Baltic Sea water during 1995-1997. It was determined that 137Cs was mainly present in ionic form (62-93 %) both in the near-shore and open waters. Concentration of particulate 137Cs ranged from 255 to 625 Bq/kg (dry weight).The distribution coefficient (Kd) of radiocaesium reached values of 2100-9700. (author)

  6. Accumulation of 137Cs in wetlands and their importance in radioecological risk assessments

    Wetlands function as nurseries and feeding areas for both terrestrial and aquatic species and are habitats for many endangered species such as frogs, salamanders and snakes. Wetlands alter the hydrology of streams and rivers, enhance sediment deposition and work as a filter to coastal waters retaining nutrients as well as contaminants. Due to the lack of easily identifiable direct pathways to humans wetland ecosystems have generally been neglected within radioecological research. There is a large diversity of wetlands and some of them can accumulate and function as sinks for radionuclides. In Sweden wetlands are among the ecosystems where the highest activity concentrations have accumulated after the Chernobyl accident. This paper summarizes factors that are important to the accumulation of radionuclides in wetlands. As an example, one wetland ecosystem in Sweden contaminated by 137Cs due to the Chernobyl accident will be described in more detail. The average activity concentration in this wetland is 1.1 MBq/m2, i.e. 10 times higher than in the surrounding areas. Soil and sediment samples were collected and the 137Cs activity concentrations were measured. A budget calculation of 137Cs in the wetland area was conducted, indicating that the accumulation of 137Cs is still ongoing seventeen years after the accident. High activity concentrations are likely to remain in this ecosystem for a long time, resulting in long-term exposure for organisms living there. The maximum external 137Cs dose rate to frogs was estimated to 96 mGy/year. Hence, identification and consideration of wetlands that accumulate radionuclides to a high extent are important in radioecological risk assessments for the protection of plants and animals from ionizing radiation. (author)

  7. Accumulation of 137Cs and 90Sr from contaminated soil by three grass species inoculated with mycorrhizal fungi

    The use of plants to accumulate low level radioactive waste from soil, followed by incineration of plant material to concentrate radionuclides may prove to be a viable and economical method of remediating contaminated areas. We tested the influence of arbuscular mycorrhizae on 137Cs and 90Sr uptake by bahia grass (Paspalum notatum), johnson grass (Sorghum halpense) and switchgrass (Panicum virginatum) for the effectiveness on three different contaminated soil types. Exposure to 137Cs or 90Sr over the course of the experiment did not affect above ground biomass of the three grasses. The above ground biomass of bahia, johnson and switchgrass plants accumulated from 26.3 to 71.7% of the total amount of the 137Cs and from 23.8 to 88.7% of the total amount of the 90Sr added to the soil after three harvests. In each of the three grass species tested, plants inoculated with Glomus mosseae or Glomus intraradices had greater aboveground plant biomass, higher concentrations of 137Cs or 90Sr in plant tissue, % accumulation of 137Cs or 90Sr from soil and plant bioconcentration ratios at each harvest than those that did not receive mycorrhizal inoculation. Johnson grass had greater aboveground plant biomass, greater accumulation of 137Cs or 90Sr from soil and plant higher bioconcentration ratios with arbuscular mycorrhizal fungi than bahia grass and switchgrass. The greatest accumulation of 137Cs and 90Sr was observed in johnson grass inoculated with G. mosseae. Grasses can grow in wide geographical ranges that include a broad variety of edaphic conditions. The highly efficient removal of these radionuclides by these grass species after inoculation with arbuscular mycorrhizae supports the concept that remediation of radionuclide contaminated soils using mycorrhizal plants may present a viable strategy to remediate and reclaim sites contaminated with radionuclides

  8. Determination of 135Cs and 137Cs in environmental samples: A review

    Radionuclides of caesium are environmentally important since they are formed as significant high yield fission products (135Cs and 137Cs) and activation products (134Cs and 136Cs) during nuclear fission. They originate from a range of nuclear activities such as weapons testing, nuclear reprocessing and nuclear fuel cycle discharges and nuclear accidents. Whilst 137Cs, 134Cs and 136Cs are routinely measurable at high sensitivity by gamma spectrometry, routine detection of long-lived 135Cs by radiometric methods is challenging. This measurement is, however, important given its significance in long-term nuclear waste storage and disposal. Furthermore, the 135Cs/137Cs ratio varies with reactor, weapon and fuel type, and accurate measurement of this ratio can therefore be used as a forensic tool in identifying the source(s) of nuclear contamination. The shorter-lived activation products 134Cs and 136Cs have a limited application but provide useful early information on fuel irradiation history and have importance in health physics. Detection of 135Cs (and 137Cs) is achievable by mass spectrometric techniques; most commonly inductively coupled plasma mass spectrometry (ICP-MS), as well as thermal ionisation (TIMS), accelerator (AMS) and resonance ionisation (RIMS) techniques. The critical issues affecting the accuracy and detection limits achievable by this technique are effective removal of barium to eliminate isobaric interferences arising from 135Ba and 137Ba, and elimination of peak tailing of stable 133Cs on 135Cs. Isobaric interferences can be removed by chemical separation, most commonly ion exchange chromatography, and/or instrumental separation using an ICP-MS equipped with a reaction cell. The removal of the peak tailing interference is dependent on the instrument used for final measurement. This review summarizes and compares the analytical procedures developed for determination of 135Cs/137Cs, with particular focus on ICP-MS detection and the methods applied

  9. Determination of {sup 135}Cs and {sup 137}Cs in environmental samples: A review

    Russell, B.C., E-mail: ben.russell@npl.co.uk [GAU-Radioanalytical, Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, SO14 3ZH (United Kingdom); National Physical Laboratory, Hampton Road, Teddington, Middlesex, TW11 0LW (United Kingdom); Croudace, Ian W.; Warwick, Phil E. [GAU-Radioanalytical, Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, SO14 3ZH (United Kingdom)

    2015-08-26

    Radionuclides of caesium are environmentally important since they are formed as significant high yield fission products ({sup 135}Cs and {sup 137}Cs) and activation products ({sup 134}Cs and {sup 136}Cs) during nuclear fission. They originate from a range of nuclear activities such as weapons testing, nuclear reprocessing and nuclear fuel cycle discharges and nuclear accidents. Whilst {sup 137}Cs, {sup 134}Cs and {sup 136}Cs are routinely measurable at high sensitivity by gamma spectrometry, routine detection of long-lived {sup 135}Cs by radiometric methods is challenging. This measurement is, however, important given its significance in long-term nuclear waste storage and disposal. Furthermore, the {sup 135}Cs/{sup 137}Cs ratio varies with reactor, weapon and fuel type, and accurate measurement of this ratio can therefore be used as a forensic tool in identifying the source(s) of nuclear contamination. The shorter-lived activation products {sup 134}Cs and {sup 136}Cs have a limited application but provide useful early information on fuel irradiation history and have importance in health physics. Detection of {sup 135}Cs (and {sup 137}Cs) is achievable by mass spectrometric techniques; most commonly inductively coupled plasma mass spectrometry (ICP-MS), as well as thermal ionisation (TIMS), accelerator (AMS) and resonance ionisation (RIMS) techniques. The critical issues affecting the accuracy and detection limits achievable by this technique are effective removal of barium to eliminate isobaric interferences arising from {sup 135}Ba and {sup 137}Ba, and elimination of peak tailing of stable {sup 133}Cs on {sup 135}Cs. Isobaric interferences can be removed by chemical separation, most commonly ion exchange chromatography, and/or instrumental separation using an ICP-MS equipped with a reaction cell. The removal of the peak tailing interference is dependent on the instrument used for final measurement. This review summarizes and compares the analytical procedures

  10. Modelling the Long Term Leaching Behaviour of 137CS from Different Stabilized Waste Matrices

    Leaching characteristics of ''1''3''7Cs from immobilized waste matrices in different cement-based grouts have been assessed to investigate the influence of the additives on the leaching behavior of the solid waste matrices. The International Atomic Energy's Agency (IAEA) standard leach method has been employed to study the leach pattern of 137Cs radionuclide from the immobilized waste form. The examination of the leaching data revealed that clay additives reduces the leach rate for the studied radionuclide. The controlling leaching mechanism has been studied and the transport parameters were calculated for all studied waste matrices. Simplified analytical models have been derived to predict the Cumulative Leach Fraction (CLF) of radionuclides over the studied experimental period. These simplified research models could be used as a screening tool to assess the performance of the waste matrix under repository conditions. (author)

  11. Mechanisms of 137Cs migration in coniferous forest soils

    Field and laboratory studies demonstrate two processes involved in 137Cs migration in coniferous forest soil. The data illustrate that the effects of leaching and litter accumulation combine, over the time interval since deposition, to achieve the observed distribution of 137Cs in the soil profile. Today, under normal field conditions the rate of 137Cs leaching from forest humus is low and even extreme environmental conditions do not increase greatly the extent of 137Cs mobilisation by leaching. A three-phase model of 137Cs migration in the organic horizons of coniferous forest soils is proposed. The phases are discrete but at any point in time the behaviour of some portion of deposited 137Cs will be characteristic of one of the three phases. In the first phase 137Cs intercepted by the canopy is washed to the forest floor where a proportion (20-40% is reported) rapidly percolates through the organic horizons reaching the underlying soil; the remainder is retained in the organic horizons. In the second phase, which our study estimates to last about 5 years, the 137Cs contained within the Ol and Of horizons moves to the Oh horizon. Accumulation of relatively uncontaminated litter on top of the Ol horizon contributes to this migration, while 137Cs mobilised from the Ol and Of horizons by decomposition is leached to the Oh horizon. The 137Cs which reaches the Oh horizon, either by leaching or by decomposition and burial, enters the third phase in which the pace of migration is greatly reduced. Decomposition is slowest in the Oh horizon and the accumulation and turnover of Oh material is also very slow. At the site investigated in this study the bulk of the deposited 137Cs is in this third phase and we suggest that this phase will persist for many years to come

  12. Physicochemical fractionation of {sup 137}Cs from TEPCO Fukushima Daiichi Nuclear Plant in irrigation water

    Tsukada, Hirofumi; Ohse, Kenji; Ishii, Hideki; Kitayama, Kyo; Nanba, Kenji; Kawatsu, Kencho [Fukushima University, 1 Kanayagawa, Fukushima, Fukushima 960-1296 (Japan)

    2014-07-01

    Significant quantities of radionuclides were released into the environment due to the TEPCO Fukushima Daiichi Nuclear Power Plant accident. Cesium-137 is the most important radionuclide for the assessment of radiation exposure to the public for the long-term. The physicochemical form of radionuclides is an important factor in determining the fate of radionuclides in the environment. For instance, {sup 137}Cs in soil can be divided into three fractions (such as exchangeable, bound to organic matter, and strongly bound to particles), and their transferability to biota and contacting waters are different. In the present study, the physicochemical fractions in rice irrigation water were determined. Sixty L of the irrigation water was collected in Oguni, Date, Fukushima (northwest 55 km far away from the Plant) in 2013. The collected sample was filtered with a 0.45 μm membrane filter (Merck Millipore, Durapore{sup R} Membrane Filters), and separated into suspended and dissolved fractions. In addition, 2000-4000 L of the irrigation water was treated by a continuous high-speed centrifugation method, and several g of suspended matter were collected. Twenty ml of concentrated nitric acid was added to 20 L of the filtrated sample and the sample was concentrated with heating, which was used to determine the total concentration of {sup 137}Cs in the dissolved fraction. Then, 5 L of the filtrated sample was passed through a Cs disk (3M, Empore{sup TM} Cesium RAD Disks) and the inorganic, cationic fraction that existed as {sup 137}Cs+ was collected. The difference between the total dissolved fraction and the inorganic fraction was defined as the dissolved organic fraction. The suspended matter collected with the centrifugation method was separated into the three solid-phase fractions noted above: exchangeable, bound to organic matter, and strongly bound to particles. Thus, the total {sup 137}Cs inventory in the irrigation water was separated into five fractions: dissolved

  13. Continuous decline of background activity concentrations of 3H, 90Sr and 137Cs in hydrosphere

    Main artificial radionuclides - 3H, 90Sr and 137Cs - have occurred in environment since atmospheric tests of nuclear weapons, and later in Europe, since the accident at the Chernobyl nuclear reactor. Hence, these radionuclides can still be detected in samples of surface water and other components of hydrosphere. To assess environmental impact of nuclear facilities, which represent point sources of artificial radioactivity, it is necessary to take into account a decreasing trend of the radionuclides background, observed in water, bottom sediments and biota. The paper describes development of 3H, 90Sr and 137Cs concentrations and balances through an example of vicinity of the Temelin Nuclear Power Plant in South Bohemia in pre-operational (1990-2000) and operational (2001-2012) stage. The concentrations of 137Cs and 90Sr were permanently decreasing during the monitored period and they cover up the same radionuclides released from the plant. In addition, similar decreasing trend was observed for tritium concentrations in river sites, which were not affected by the plant, too. In contrast to the other radionuclides, concentrations of tritium detected at the sites affected by the plant were substantially above its background. Document available in abstract form only. (authors)

  14. Levels of 137Cs in muddy sediments on the seabed in the Bay of Cadiz (Spain). Part II. Model of vertical migration of 137Cs

    This second part of the study reports the development of a model to describe the vertical migration of the artificial radioisotope 137Cs in the sediment column on the seabed of the Bay of Cadiz. The application of the model provides an overall picture of the process of sedimentation in the Inner Bay of Cadiz. The spatial distribution of the rate of sedimentation enables us to study the sources of sediments and the means by which the sediments have been transported. A method has been derived from the rate of sedimentation to perform the dating of the layers of sediment. The model describes the behaviour of 137Cs in the area under study, taking into account the time of residence in the zones that are the source of accumulation, the origin of the sedimentary material, together with the diffusion of the radionuclide in the sediment of the seabed

  15. Bioavailability of 137Cs - geographical variability in Swedish forest- and arable soil. Construction of a database using GIS

    Soil acts as a sink for long-lived radionuclides such as 137Cs . The bioavailability and the plant root uptake of 137Cs are therefore influenced by chemical and physical characteristics of the soil. The aim of this study is to gather information about Swedish soil conditions, focusing on parameters known to influence the bioavailability of 137Cs and to indicate areas which may have a higher probability of containing persistent bioavailable 137Cs. This project was carried out in two parts. First, an information database on soil properties in Swedish forest and agricultural landscapes was constructed using GIS (Geographic Information System). Next, Swedish agricultural and forest soils were characterised according to low, intermediate and high estimated bioavailability of 137Cs. Agricultural soils were ranked according to clay and organic matter content; forest soils according to podzol, cambisol and peat. The physical and chemical properties of agricultural soils are quite different from forest soils. In contrast to forest soils, agricultural soils are characterised by reduced quantities of organic matter and a higher proportion of clay. Several investigations have indicated. a faster decline in 137Cs levels in agricultural soils when compared to forest soils. Due to these differences, these soil types are dealt with separately in this report

  16. Soil-to-plant transfer of 137Cs and 40K in an Atlantic blanket bog ecosystem

    The transfer of 137Cs and 40K from soil to vegetation was studied in an Atlantic blanket bog ecosystem along the Atlantic coast of Ireland where the dominant vegetation is a mixture of Calluna vulgaris, Eriophorum vaginatum and Sphagnum mosses. The impact of soil chemistry and nutritional status of vegetation on the uptake of both radionuclides was also examined. Cesium-137 transfer factors values ranged from 1.9 to 9.6 and accumulation of 137Cs was higher in the leaves of C. vulgaris than in the stems. Transfer factors values for 137Cs in both C. vulgaris and E. vaginatum were similar indicating that for the vegetation studied, uptake is not dependent on plant species. The uptake of 137Cs in bog vegetation was found to be positively correlated with the nutrient status of vegetation, in particular the secondary nutrients, calcium and magnesium. Potassium-40 transfer factors ranged from 0.9 to 13.8 and uptake was higher in E. vaginatum than in C. vulgaris, however, unlike 137Cs, the concentrations of 40K within the leaves and stems of C. vulgaris were similar. The concentration of both 137Cs and 40K found in moss samples were in general lower than those found in vascular plants. (author)

  17. 137Cs in biota and sediment samples from Turkish coast of the Black Sea, 1997-1998

    During the periods of 1997-1998, macroalgae, sea snail, mussel, fish and sediment samples were collected from different stations at Turkish Black Sea coast in order to determine activity levels of 137Cs radionuclide. 137Cs activity in the tested algae species and in soft parts of mussel and sea snail, were found to be below the lower limit of detection. On the other hand, the 137Cs concentration in muscle tissue of the sea snail samples were found from 6±2 to 19±7 Bq x kg-1 dry weight. The range of the 137Cs concentration in anchovy fish muscles were found between 4±2 - 10±5 Bq x kg-1 dry weight. The 137Cs concentration in the whiting fish muscle was found below the lower limit of detection. However, this activity found in shad fish muscle to be 25±10 Bq x kg-1 dry weight. The concentrations of the 137Cs activity in the sediment samples proved that the eastern region of the Black Sea was affected by Chernobyl at a very high degree compared with the western part. The measured 238U, 232Th and 40K concentrations in sediment samples are within the range of the cited values in the previous works at the Turkish Black Sea coast. (author)

  18. Long-term decline of 137Cs concentration in honey in the second decade after the Chernobyl accident

    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

  19. Transfer of Chernobyl-derived 134Cs, 137Cs, 131I and 103Ru from flowers to honey and pollen

    The activity concentrations of 137Cs, 134Cs, 131I and 103Ru were determined separately in honey and pollen samples collected from a single bee colony during several months after the deposition of Chernobyl fallout. The source of each honey and pollen sample was determined by pollen analysis. Although the activity concentrations in honey and pollen varied with time, the concentrations of 137Cs and 134Cs were, in general, higher in pollen than in honey. For 103Ru and 131I, these differences were comparatively small. The mean 131I/137Cs and 103Ru/137Cs ratios were about one order of magnitude higher in honey than in pollen. The mean 131I/103Ru ratio was about the same for honey and pollen. This observation, in the light of the corresponding nuclide ratios found in the deposition, suggests that 137Cs, 134Cs, 131I and 103Ru were taken up by the plant leaves and transported to nectar and pollen. The higher activity concentrations of 137Cs and 134Cs in pollen, relative to honey, indicate that these radionuclides behave analogously to potassium, which is also found in higher quantities in pollen. (author)

  20. Ecological half-life of 137Cs in fish from a stream contaminated by nuclear reactor effluents

    Radiocesium (137Cs) concentrations were determined during 1974, 1981 and 1998 for seven species of fish inhabiting a stream (Steel Creek) contaminated by effluents from a nuclear reactor to examine the decline of this radionuclide in a natural ecosystem. Median 137Cs concentrations were highest in Micropterus salmoides (largemouth bass) during each year of the investigation (1974=6.67 Bq g-1 dry wt. of whole body; 1981=3.72 Bq g-1; 1998=0.35 Bq g-1), but no patterns of differences were observed among Aphredoderus sayanus (pirate perch), Esox americanus (redfin pickerel), Lepomis auritus (redbreast sunfish), L. gulosus (warmouth), L. punctatus (spotted sunfish), and Notropis cummingsae (dusky shiner). Results demonstrated a rapid decline in 137Cs within fish from Steel Creek during the 24-year period. For example, 137Cs concentrations in all fish species declined significantly among years, even after accounting for radioactive decay. The observed percent declines in 137Cs concentrations of individual species were 3-4 times greater between 1974 and 1981 compared to that expected by physical decay alone, and 2-3 times greater during 1981-1998. Ecological half-lives (EHLs) of 137Cs in fish ranged from 4.43 years in A. sayanus to 6.53 years in L. gulosus. The EHL for 137Cs in all fish species combined was 5.54 years. Current levels of 137Cs in fish from Steel Creek (1.16 Bq g-1 dry wt. of whole body to below detection limits) indicate that the consumption of fish from this ecosystem poses little risk to humans and sensitive wildlife species. These results demonstrate the importance of incorporating the concept of ecological half-life into determinations concerning the length and severity of potential risks associated with radiocontaminants

  1. Numerical simulation of 137Cs and 239,240Pu concentrations by an ocean general circulation model

    We simulated the spatial distributions and the temporal variations of 137Cs and 239,240Pu concentrations in the ocean by using the ocean general circulation model which was developed by National Center of Atmospheric Research. These nuclides are introduced into seawaters from global fallout due to atmospheric nuclear weapons tests. The distribution of radioactive deposition on the world ocean is estimated from global precipitation data and observed values of annual deposition of radionuclides at the Meteorological Research Institute in Japan and several observed points in New Zealand. Radionuclides from global fallout have been transported by advection, diffusion and scavenging, and this concentration reduces by radioactive decay in the ocean. We verified the results of the model calculations by comparing simulated values of 137Cs and 239,240Pu in seawater with the observed values included in the Historical Artificial Radionuclides in the HAM database, which has been constructed by the Meteorological Research Institute. The vertical distributions of the calculated 137Cs concentrations were in good agreement and are in good agreement with the observed profiles in the 1960s up to 250 m, in the 1970s up to 500 m, in the 1980s up to 750 m and in the 1990s up to 750 m. However, the calculated 137Cs concentrations were underestimated compared with the observed 137Cs at the deeper layer. This may suggest other transport processes of 137Cs to deep waters. The horizontal distributions of 137Cs concentrations in surface water could be simulated. A numerical tracer release experiment was performed to explain the horizontal distribution pattern. A maximum 239,240Pu concentration layer occurs at an intermediate depth for both observed and calculated values, which is formed by particle scavenging. The horizontal distributions of the calculated 239,240Pu concentrations in surface water could be simulated by considering the scavenging effect

  2. Cumulative deposition of 137Cs in the soil of Korea

    The cumulative deposition of 137Cs in the soil of Korea has been studied. Using γ-ray spectrometry, the concentrations of 137Cs were determined for the soil samples collected to a depth of 20 cm. The average accumulated depositions of 137Cs were estimated roughly to be 2,501 ±499 Bq m-2 in the forest and 1,058 ±322 Bq m-2 in the hill. The inventory value of 137Cs in the forest is about two times higher than that in the hill. Except for some cases, the concentrations of 137Cs in the undisturbed soils decreased exponentially with increasing the soil depth. The influences of rainfall, organic matter content, clay content and pH on the deposition of 137Cs were studied using the field method. Among these factors, the organic matter content played the most important role in the retention and relative mobility of 137Cs in the soil. The other factors such as rainfall, clay content and pH showed weak correlation with the deposition of 137Cs in the soil

  3. Effect of potassium fertilizers on 137Cs transfer from sandy soddy-podzolic soil to plants

    The purpose of the work is to study the behavior of potassium in sandy soddy podzolic soil and its influence on the availability of 137 Cs to plants of winter rye and lupine when applying various doses of potassium fertilizers (PF) and turf-manure compost (TMC). A many-years stationary experiment was established in the Bryansk region in 1986-1988 on soddy podzolic soil contaminated by the accident at the Chernobyl Power Station. The influence of fertilizer was studied in 4-field crop rotation in an experimental plot: seeded fallow (lupine, bird's-foot) – winter rye – potato – spring grains. Potassium and mineral fertilizers were applied. It was shown that the application of potassium fertilizers (from 0 to 180 kg/ha) increased the content of exchangeable potassium in the soil by 1.7-2-7 times and its mobility by 2.5-4.0 times which resulted in a decrease of 137Cs transfer to plants by 5.8-14 times. The inverse proportional relationship was found between the potassium mobility and the content of its mobile form and the accumulation coefficient of 137Cs by lupine and wheat rye plants. A linear relationship was reveled between the accumulation coefficient of 137Cs and the content of exchangeable radionuclide

  4. Background distributions of 239+240Pu and 137Cs of upland soil in Rokkasho, Japan

    The background distributions of Pu and 137Cs in soil were investigated in Rokkasho, Aomori Prefecture, where the first commercial nuclear fuel reprocessing plant in Japan is now being constructed. Soil core samples to 1 m depth were collected at 13 upland fields in Rokkasho and control sites in Hachinohe and Hirosaki. Since fields under yam (Dioscorea babatus) cultivation, which is a common crop in Rokkasho, were dug to approximately 1 m depth at harvesting, depth profiles of fallout radionuclides are heavily disturbed for most fields in Rokkasho. The mean inventories of 239+240Pu and 137Cs in three fields with no yam cultivation history were 116 Bq m-2 and 3.4 kBq m-2, respectively and similar to values in Hachinohe. However, the inventories were approximately a half of those in Hirosaki. The mean ratio of 239Pu/240Pu for all studied fields was 0.18±0.04, and similar to that of global fallout. The Pu concentrations correlate very well with 137Cs (r=0.97) in spite of heavy disturbance of soil, and the ratio of 239+240Pu/137Cs was 0.037±0.007, which is a typical value for global fallout. (author)

  5. Ecological half-life of 137Cs in plants associated with a contaminated stream

    Ecological half-life (Te) is a useful measure for studying the long-term decline of contaminants, such as radionuclides, in natural systems. The current investigation determined levels of radiocesium (137Cs) in two aquatic (Polygonum punctatum, Sagittaria latifolia) and three terrestrial (Alnus serrulata, Myrica cerifera, Salix nigra) plant species from a contaminated stream and floodplain on the U.S. Department of Energy's Savannah River Site. Current 137Cs levels in plants were used in conjunction with historical data to determine Te of 137Cs in each species. Median concentrations of 137Cs were highest in S. latifolia (0.84 Bq g-1) and lowest in M. cerifera (0.10 Bq g-1). Te's ranged from 4.85 yr in M. cerifera to 8.35 yr in S. nigra, both terrestrial species. Te's for all aquatic (6.30 yr) and all terrestrial (5.87) species combined were very similar. The Te's of the two aquatic primary producers (P. punctatum and S. latifolia) in the Steel Creek ecosystem were somewhat longer than Te values previously reported for some consumers from this ecosystem

  6. 90SR and 137CS distribution in organisms of wild small mammals (Chernobyl zone)

    The distribution of 90Sr and 137Cs content in tissues of small rodent mammals has been studied in detail. It was determined that for a vole Microtus the largest ratio values of 137Cs concentration in organs to one in muscles are in skin (2.02±0.45) and kidneys (1.57±0.29), in other tissues they are much lower. The comparison of 137Cs specific concentration in tissues with their size (mass index) has shown that the major portion of the total radionuclide concentration in the animal body is in the bone and muscle tissues aggregate (44.1 ± 2.8%) and in skin (24.8 ± 2.5%). The total content of 137Cs in a gastrointestinal tract is about 20-25%, but nevertheless, it may be assumed that it is strongly dependent on the radioactivity of food. Preliminary data show that other species of genus Microtus can have another pattern of distribution. A more detailed research was conducted for the bank vole (Clethrionomys glareolus), 90Sr and 137Cs contents in tissues were calculated. 137Cs distribution corresponds with the tissues portion in the animal's body mass (% of total content): the most in muscles 38.3, gastrointestinal tract 21.3, skin 16.7; the least in eyes 0.23, spleen 0.33, heart 0.74. The comparison of the activity concentration in each tissue with the average concentration of 137Cs in the whole body presented more evident differences between the tissues. The highest radionuclide concentration is in skin (1.48), in a slightly less degree in spleen (1.22) and eyes (1.20). The 90Sr distribution in the vole body is uneven up to 83.4% of the overall content is in bone tissues, in muscle -6.8, gastrointestinal tract - 4.2, skin - 3.9, in other tissues - 0.2-0.5%. In comparison with 90Sr average activity in the body: skeleton -10.9, eyes -1.3, spleen -1.02, and their values are much higher than in other tissues and organs. (author)

  7. Sediment environmental capacity of 137Cs in Daya Bay

    ZHANG Junli; CHEN Jiajun; XU Jialin; LI Yuanxin; HUANG Naiming

    2007-01-01

    Sediment environmental capacity of pollutants is very important for marine environmental management.Based on the methodology of a study on water,soil environmental capacity,and mass conservation theory in a system,the concept and model on sediment environmental capacity for 137Cs in Daya Bay were developed.The static capacity for 137Cs in the upper sediment near the shore at a shallow area was calculated,and the annual dynamic capacity and total dynamic capacity were also calculated through determination of the typical biomass in the sediment.The results showed that the estimated environmental capacity for 137Cs in sediments was approximately equal to the current input of 137Cs into the sediments.Controlling the input of 137Cs in the sediments within the environmental capacity guarantees the sustainability of the current situation of the Daya Bay ecosystem and avoidance of a significant degradation of the system.

  8. {sup 137}Cs accumulation in coastal sediments in Sweden

    Pettersson, H.B.L.; Salih, I. [Linkoeping Univ. (Sweden). Dept. of Radiation Physics; Herrmann, J. [Federal Maritime and Hydrographic Agency, Hamburg (Germany)

    2005-09-15

    Seabed sediment samples were collected in 1998, 2000 and 2001 at 20 sites located in the Baltic Sea and 4 sites in the Skagerrak. The objectives of the sampling campaigns were (i) to establish the coastal sediment distribution of {sup 137}Cs, (ii) to evaluate the vertical core distribution of {sup 137}Cs, (iii) to study the sediment accumulation rates, and (iv) to assess the sediment inventories of {sup 137}Cs. The results show a very high variation in {sup 137}Cs concentrations and an almost 100-fold difference in inventories, showing predominance of Chernobyl derived {sup 137}Cs in the Baltic Proper compared to the western Baltic and the Skagerrak areas. Sediment accumulation rates were highly dependent on sediment types and ranged from 0.05 to 1.8 cm/y.

  9. Evaluating gully erosion using 137Cs and 210Pb/137Cs ratio in a reservoir catchment

    Water erosion in the hilly areas of west China is the main process contributing to the overall sediment of the Yellow River and the Yangtze River. The impact of gully erosion in total sediment output has been mostly neglected. Our objective was to assess the sediment production and sediment sources at both the hillslope and catchment scales in the Yangjuangou reservoir catchment of the Chinese Loess Plateau, northwest China. Distribution patterns in sediment production caused by water erosion on hills and gully slopes under different land use types were assessed using the fallout 137Cs technique. The total sediment production from the catchment was estimated by using the sediment record in a reservoir. Sediment sources and dominant water erosion processes were determined by comparing 137Cs activities and 210Pb/137Cs ratios in surface soils and sub-surface soils with those of sediment deposits from the reservoir at the outlet of the catchment. Results indicated that landscape location had the most significant impact on sediment production for cultivated hillslopes, followed by the terraced hillslope, and the least for the vegetated hillslope. Sediment production increased in the following order: top>upper>lower>middle for the cultivated hillslope, and top>lower>upper>middle for the terraced hillslope. The mean value of sediment production declined by 49% for the terraced hillslope and by 80% for the vegetated hillslope compared with the cultivated hillslope. Vegetated gully slope reduced the sediment production by 38% compared with the cultivated gully slope. These data demonstrate the effectiveness of terracing and perennial vegetation cover in controlling sediment delivery at a hillslope scale. Averaged 137Cs activities and 210Pb/137Cs ratios in the 0-5 cm surface soil (2.22-4.70 Bq kg-1 and 20.70-22.07, respectively) and in the 5-30 cm subsoil (2.60 Bq kg-1 and 28.57, respectively) on the cultivated hills and gully slopes were close to those of the deposited

  10. Re-distribution of 137Cs Chernobyl signal in the Aegean Sea

    The Chernobyl accident produced a patchy deposition of radionuclides over the Eastern and Northern basins of the Mediterranean Sea, that was superimposed over the previous fallout from atmospheric nuclear weapon tests. The deposition of Chernobyl-derived 137Cs was particularly heavy onto the Black Sea (1.7 - 2.4 PBq) and the Aegean - Ionian Seas along the Greek coasts (800 TBq). Moreover, the inflow of surface Black Sea water through the Dardanelles Straits still constitutes a point source of the conservative 137Cs into the North Aegean Sea. The objective of this study is to discuss the relationship between the re-distribution of 137Cs Chernobyl signal in the Aegean Sea and water circulation in the area, with focus on the evolution in space and time on the events of deep water formation. Selected sampling was carried out in 1999, 2001, 2002 and 2003 by the Hellenic Centre for Marine Research and the Italian ENEA Marine Environment research Centre during oceanographic campaigns designed for other purposes. Due to the limited ship time available, particular attention was dedicated to gather information on the 137Cs vertical profiles in the water column of selected sites (deep North-Aegean Basins and Cretan Sea), where the signal of past events involving deep water formation is expected to be registered. The water exiting the Dardanelles undergoes mixing with North Aegean surface water. In the surface water, there is a clear trend of decreasing 137Cs concentration with increasing salinity, suggesting that mixing/dilution of Black Sea Water (BSW) with highly saline Aegean waters is the dominant process determining the 137Cs levels. Due to its low salinity, BSW acts as an insulation layer and, consequently, deep-water formation is rather infrequent in the North Aegean, taking place only at periods of reduced Black Sea outflow and/or exceptionally cold and dry winters. In the last 20 years there have been two major deep-water formation events in the North Aegean: in

  11. Biogeochemical behaviour of 137Cs and 90Sr in the artificial reservoirs of Mayak PA, Russia

    Strand, P.; Brown, J.E.; Amundsen, I. [Norwegian Radiation Protection Authority, Grini naeringspark 13, P.O. Box 55, N-1332 Oesteraas (Norway); Drozhko, E.; Mokrov, Y. [Mayak Production Association, 31, Lenin St, 45065 Chelyabinsk-65 (Russian Federation); Salbu, B.; Oughton, D. [Laboratory for Analytical Chemistry, Agricultural University of Norway, N-1432 Aas (Norway); Christensen, G.C. [Institute for Energy Technology, Health and Safety Department, Institute for Energy Technology, P.O. Box 40, N-2007 Kjeller (Norway)

    1999-10-29

    The Mayak Production Association (PA) in the southern Urals, Russia was the site of the first weapons-grade plutonium production reactor complex in Russia. The site and surrounding area have been significantly contaminated by direct discharges of radionuclides for over 40 years, the Techa River alone having received more than 100 PBq of waste in the period 1949-1956. The aim of this study was to consider the levels of 90Sr and 137Cs in water, sediment and biota samples for two industrial reservoirs in the Mayak PA area, thus allowing a biogeochemical assessment of the behaviour of radionuclides in the system. Four sediment cores were collected and sectioned along with four water samples and seven fish samples (pike, perch and roach). Samples were analysed using (1) standard gamma-spectrometric techniques (HPGe and NaI(Tl) detectors) for 137Cs determination; and (2) radiochemical separation and beta-counting (low-background, anti-coincidence and Geiger-Muller counters) for 90Sr determination. Maximum specific activities (dry weight) of 3350 kBq kg{sup -1} {sup 137}Cs and 720 kBq kg{sup -1} {sup 90}Sr were measured in sediments from Reservoir 10. Activity levels of sediment-bound radionuclides in Reservoir 11 were 403 kBq kg{sup -1} {sup 137}Cs and 670 kBq kg{sup -1} {sup 90}Sr. Water concentrations in Reservoir 10 were as high as 100 Bq l{sup -1} {sup 137}Cs and 8.4-14 kBq l{sup -1} {sup 90}Sr. A dramatic decrease in 137Cs concentrations was observed in Reservoir 11, i.e. 1.1-1.5 Bq l{sup -1}, but 90Sr levels fell to a lesser extent, i.e. 1.9-2.4 kBq l{sup -1}. Sediment and water activity data allowed the calculation of distribution coefficients (K{sub d} values). This parameter fluctuated for both radionuclides reflecting the heterogeneous nature of the sediment deposits in the reservoirs. Caesium-137 Concentration Factors (CFs) as high as 1400 l kg{sup -1} were calculated for pike from Reservoir 10. A pronounced 'trophic level' effect was evident in

  12. Accumulation of 137Cs in commercial fish of the Belyarsk nuclear power station cooling supply

    Results are presented of a comparative study of the accumulation of 137Cs in basic species of commercial fish of the Beloyarsk reservoir which is used as the cooling supply for the Beloyarsk nuclear power station. Possible reasons for interspecies differences in accumulation of the radionuclide are indicated, and the increased accumulation of 137Cs by free-living fish in the zone of heated water effluent from the station and the reduced accumulation of the emitter in carp, which are cultivated on artificial food in cages, are noted. Levels of the content of the radionuclide are compared in roach and farm carp from the cooling supplies of the Beloyarsk station and the Reftinsk power plant in the Urals

  13. Activity concentrations of 137Cs and 40K in mosses from spas in Eastern Serbia

    With the aim of detecting the presence of radionuclides in moss samples in eastern Serbia, 129 samples of mosses were collected from 2000 to 2010 in the region of the spas: Sokobanja, Banja Jošanica and Gamzigradska banja. The data obtained show that 137Cs was present in all of the 129 samples from 3 sampling areas and 15 sampling localities and in 20 moss taxa. This indicates that pollution with this radionuclide resulting from the Chernobyl accident still exists. Changes in the average activity concentrations of 40K are within measurement error limits, while for 137Cs changes in the average activity concentrations are more noticeable, i.e. they have decreased with tim

  14. 137Cs in the western South Pacific Ocean

    The 137Cs activities were determined for seawater samples from the East Caroline, Coral Sea, New Hebrides, South Fiji and Tasman Sea (two stations) Basins of the western South Pacific Ocean by γ spectrometry using a low background Ge detector. The 137Cs activities ranged from 1.4 to 2.3 Bq m-3 over the depth interval 0-250 m and decreased exponentially from the subsurface to 1000 m depth. The distribution profiles of 137Cs activity at these six western South Pacific Ocean stations did not differ from each other significantly. There was a remarkable difference for the vertical profiles of 137Cs activity between the East Caroline Basin station in this study and the GEOSECS (Geochemical Ocean Sections Study) station at the same latitude in the Equatorial Pacific Ocean; the 137Cs inventory over the depth interval 100-1000 m increased from 400 ± 30 Bq m-2 to 560 ± 30 Bq m-2 during the period from 1973 to 1992. The total 137Cs inventories in the western South Pacific Ocean ranged from 850 ± 70 Bq m-2 in the Coral Sea Basin to 1270 ± 90 Bq m-2 in the South Fiji Basin. Higher 137Cs inventories were observed at middle latitude stations in the subtropical gyre than at low latitude stations. The 137Cs inventories were 1.9-4.5 times (2.9 ± 0.7 on average) and 1.7-4.3 times (3.1 ± 0.7 on average) higher than that of the expected deposition density of atmospheric global fallout at the same latitude and that of the estimated 137Cs deposition density in 10o latitude by 10 deg. longitude grid data obtained by Aoyama et al. [Aoyama M, Hirose K, Igarashi Y. Re-construction and updating our understanding on the global weapons tests 137Cs fallout. J Environ Monit 2006;8:431-438], respectively. The possible processes for higher 137Cs inventories in the western South Pacific Ocean than that of the expected deposition density of atmospheric global fallout may be attributable to the inter-hemisphere dispersion of the atmospheric nuclear weapons testing 137Cs from the northern

  15. Phytodemutation effect on the 137Cs redistribution within Chernobyl urbanized landscapes

    The conception of 'radiometry anticipation' is determined. This one used for estimation of gamma-emitting radionuclide contamination dynamics within Chernobyl urbanized landscapes. Estimation of phytodemutation is conducted by analysis of the spatial distributing of trees crowns serriedness ratio. Comparison of the spatial distributing of contamination of soil by a 137Cs and level of Chernobyl urbanized landscapes phytodemutation is executed for period from 1990 to 2006

  16. The influence of soil macromycetes on the accumulation of 137 Cs by sugar beet and clover

    The results of field experiments for studying of the influence of soil micobiota on the accumulation of 137Cs by agricultural plants from the soil of nord (fuel) trace are presented. Data for two cultures (sugar beet and clover) and for two strains of soil micromycetes have been obtained. These data show that in some cases soil micobiota can have dominant influence on the transfer of radionuclides into agricultural plants

  17. 137Cs and 210Po in Pacific Walrus and Bearded Seal from St. Lawrence Island, Alaska

    Hamilton, T F; Seagars, D J; Jokela, T; Layton, D

    2005-02-02

    The activity concentration of Cesium-137 ({sup 137}Cs) and naturally-occurring Polonium-210 ({sup 210}Po) were measured in the muscle tissue, kidney and liver of Pacific walrus (Odobenus rosmarus divergens) and bearded seal (Erignathus barbatus) collected by native hunters from the Bering Sea. The mean {sup 137}Cs concentrations in muscle, liver and kidney of Pacific walrus were 0.07, 0.09 and 0.07 Bq kg{sup -1} (N= 5, wet weight), respectively, and 0.17, 0.10, and 0.17 Bq kg{sup -1} (N=2, wet weight), respectively, in bearded seal. In general, {sup 137}Cs tissue concentrations are significantly lower than those previously reported for mammals from other regions. By comparison, {sup 210}Po activity concentrations appear to be higher than those reported elsewhere but a larger variation. The mean {sup 210}Po concentration in the muscle tissue, liver and kidney of Pacific walrus (N=5, wet weight) were 28.7, 189, and 174 Bq kg{sup -1}, respectively. This compares with {sup 210}Po concentration values (N=2, wet weight) of 27, 207, and 68 Bq kg{sup -1} measured in the muscle tissue, liver and kidney, of bearded seal, respectively. Estimated bioaccumulation factors--as defined by the radionuclide concentration ratio between the target tissue to that in sea water--were two to three orders of magnitude higher for {sup 210}Po that those of {sup 137}Cs. We conclude from radiological dose estimates that ingestion of {sup 137}Cs in foods derived from walrus and seal will pose no threat to human health. This work has important implications for assessing health risks to Alaskan coastal communities concerned about the dumping of nuclear waste in the Russia Arctic.

  18. Enviromental influences on the 137Cs kinetics of the yellow-bellied turtle (Trachemys Scripta)

    Assessments of ecological risk require accurate predictions of contaminant dynamics in natural populations. However, simple deterministic models that assume constant uptake rates and elimination fractions may compromise both their ecological realism and their general application to animals with variable metabolism or diets. In particular, the temperature-dependent model of metabolic rates characteristic of ectotherms may lead to significant differences between observed and predicted contaminant kinetics. We examined the influence of a seasonally variable thermal environment on predicting the uptake and annual cycling of contaminants by ectotherms, using a temperature-dependent model of 137Cs kinetics in free-living yellow-bellied turtles, Trachemys scripta. We compared predictions from this model with those of deterministics negative exponential and flexibly shaped Richards sigmoidal models. Concentrations of 137Cs in a population if this species in Pond B, a radionuclide-contaminated nuclear reactor cooling reservoir, and 137Cs uptake by the uncontaminated turtles held captive in Pond B for 4 yr confirmed both the pattern of uptake and the equilibrium concentrations predicted by the temperature-dependent model. Almost 90% of the variance on the predicted time-integrated 137Cs concentration was explainable by linear relationships with model paramaters. The model was also relatively insensitive to uncertainties in the estimates of ambient temperature, suggesting that adequate estimates of temperature-dependent ingestion and elimination may require relatively few measurements of ambient conditions at sites of interest. Analyses of Richards sigmoidal models of 137Cs uptake indicated significant differences from a negative exponential trajectory in the 1st yr after the turtles' release into Pond B. 76 refs., 7 figs., 5 tabs

  19. 137Cs and 210Po in Pacific walrus and bearded seal from St. Lawrence Island, Alaska

    The activity concentration of Cesium-137 (137Cs) and naturally-occurring Polonium-210 (210Po) were measured in the muscle tissue, kidney and liver of Pacific walrus (Odobenus rosmarus divergens) and bearded seal (Erignathus barbatus) collected by native hunters from the Bering Sea during May 1996. The mean 137Cs concentrations in muscle, liver and kidney of Pacific walrus were 0.07, 0.09 and 0.07 Bq kg-1 (n = 5, wet weight), respectively, and 0.17, 0.10, and 0.17 Bq kg-1 (n = 2, wet weight), respectively, in bearded seal. In general, 137Cs tissue concentrations are significantly lower than those previously reported for mammals from other regions. By comparison, 210Po activity concentrations are more variable and appear to be higher level compared with mammal data from other regions. The mean 210Po concentration in the muscle tissue, liver and kidney of Pacific walrus (n = 5, wet weight) were 28.7, 189, and 174 Bq kg-1, respectively. This compares with 210Po concentration values (n = 2, wet weight) of 27, 207 and 68 Bq kg-1 measured in the muscle tissue, liver and kidney, of bearded seal, respectively. Estimated concentration factors-as defined by the radionuclide concentration ratio between the target tissue to that in sea water-were two to three orders of magnitude higher for 210Po that those of 137Cs. We conclude from radiological dose estimates that ingestion of 137Cs in foods derived from walrus and seal will pose no threat to human health. This work has important implications for assessment of risks of Alaskan coastal communities concerned about the dumping of nuclear waste in the Russia Arctic

  20. 137Cs and 210Po in Pacific Walrus and Bearded Seal from St. Lawrence Island, Alaska

    The activity concentration of Cesium-137 (137Cs) and naturally-occurring Polonium-210 (210Po) were measured in the muscle tissue, kidney and liver of Pacific walrus (Odobenus rosmarus divergens) and bearded seal (Erignathus barbatus) collected by native hunters from the Bering Sea. The mean 137Cs concentrations in muscle, liver and kidney of Pacific walrus were 0.07, 0.09 and 0.07 Bq kg-1 (N= 5, wet weight), respectively, and 0.17, 0.10, and 0.17 Bq kg-1 (N=2, wet weight), respectively, in bearded seal. In general, 137Cs tissue concentrations are significantly lower than those previously reported for mammals from other regions. By comparison, 210Po activity concentrations appear to be higher than those reported elsewhere but a larger variation. The mean 210Po concentration in the muscle tissue, liver and kidney of Pacific walrus (N=5, wet weight) were 28.7, 189, and 174 Bq kg-1, respectively. This compares with 210Po concentration values (N=2, wet weight) of 27, 207, and 68 Bq kg-1 measured in the muscle tissue, liver and kidney, of bearded seal, respectively. Estimated bioaccumulation factors--as defined by the radionuclide concentration ratio between the target tissue to that in sea water--were two to three orders of magnitude higher for 210Po that those of 137Cs. We conclude from radiological dose estimates that ingestion of 137Cs in foods derived from walrus and seal will pose no threat to human health. This work has important implications for assessing health risks to Alaskan coastal communities concerned about the dumping of nuclear waste in the Russia Arctic

  1. Dynamics of 137Cs in the forests of the 30-km zone around the Chernobyl nuclear power plant

    Dynamics of the 137Cs content in the components of the forests in the 30-km zone around the Chernobyl nuclear power plant (NPP) in 1986–1994 are associated mainly with such factors as the size of radioactive particles in the fallout, ecosystem humidification and soil type, tree age. The influence of particle size was especially noticable between 1986–1987 and was displayed by low biological availability of radionuclides in the near part of the zone (within the 10-km radius circle around the NPP) in comparison with more distant regions (within the 30-km radius circle). Later, the expression of this influence decreased and transfer factor (the ratio of 137Cs content in overground phytomass to the soil contamination density) became approximately the same for all plots with similar ecological and fallout characteristics. Humidity of landscape and soil type determined the velocity of radionuclide vertical migration in the soil and 137Cs biological availability. These parameters were maximum for the hydromorphic soils of wet landscapes enriched in organic substance and poor clayey minerals. Differences of 137Cs accumulation in overground phytomass of trees caused by tree age are displayed in the higher 137Cs concentration in structural parts of young trees as compared with old ones

  2. Dynamics of 137Cs in the forests of the 30-km zone around the Chernobyl nuclear power plant

    Dynamics of the 137Cs content in the components of the forests in the 30-km zone around the Chernobyl nuclear power plant (NPP) in 1986-1994 are associated mainly with such factors as the size of radioactive particles in the fallout, ecosystem humidification and soil type, tree age. The influence of particle size was especially noticeable between 1986-1987 and was displayed by low biological availability of radionuclides in the near part of the zone (within the 10-km radius circle around the NPP) in comparison with more distant regions (within the 30-km radius circle). Later, the expression of this influence decreased and transfer factor (the ratio of 137Cs content in overground phytomass to the soil contamination density) became approximately the same for all plots with similar ecological and fallout characteristics. Humidity of landscape and soil type determined the velocity of radionuclide vertical migration in the soil and 137Cs biological availability. These parameters were maximum for the hydromorphic soils of wet landscapes enriched in organic substance and poor clayey minerals. Differences of 137Cs accumulation in overground phytomass of trees caused by tree age are displayed in the higher 137Cs concentration in structural parts of young trees as compared with old ones

  3. Transfer factors of 137Cs and 9Sr from soil to trees in arid regions

    Transfer factors of 137Cs and 9Sr from contaminated soil (Aridisol) to olive, apricot trees and grape vines were determined under irrigated field conditions for four successive years. The transfer factors (calculated as Bq kg-1 dry plant material per Bq kg-1 dry soil) of both radionuclides varied among tree parts and were highest in olive and apricot fruits. However, the values for 9Sr were much higher than those for 137Cs in all plant parts. The geometric mean of the transfer factors in olives, apricots and grapes were 0.007, 0.095 and 0.0023 for 137Cs and 0.093, 0.13 and 0.08 for 9Sr, respectively, and were negligible in olive oil for both radionuclides. The transfer factors of both radionuclides were similar to, or in the lower limits of, those obtained in other areas of the world. This could be attributed to differences in soil characteristics: higher pH, lower organic matter, high clay content, and higher exchangeable potassium and calcium

  4. Transfer and mobility of 137 Cs and 60 Co in oxisol and alfisol

    One manner to assess potential mobility of radionuclides in soils is the use of sequential extraction procedures. These procedures intend to provide the radionuclide partitioning in geochemical phases of soil affected by changes in physico-chemical conditions. In this study a new sequential chemical extraction protocol was choose to evaluate 60 Co and 137 Cs mobility under a large range of physico-chemical soil properties. The results of sequential procedure was further compared with soil to plant transfer factors data for maize and radish and with soil properties, showing rather consistent results. The 137 Cs distribution in soil showed that Fe oxides are the main sink for this element and after 14 years after contamination the 137 Cs was still available for plants. The 60 Co distribution showed that Mn oxides are the main sink for this element in Alfisol and 5 years after contamination no 60 Co was detected as bioavailable neither detectable in maize. The knowledge of the bio-geochemical behavior of radionuclides in soil system can be useful for risk assessment studies, to be applied in the case of nuclear accident or contamination scenarios. (author)

  5. Transfer of 137Cs from cooking water to some green-stuffs samples

    The radionuclide in contaminated freshwater may directly gain access to the human body by drinking fresh water and cooking food with such water. During cooking, the radionuclide present in the water may be transferred to the various ingredients of the cooked food. The ratio of the concentration of the radionuclide absorbed in the individual ingredients to the concentration in the cooking water can be designated as the Transfer factor in cooking (TFC). The TFC's of 137Cs in some green-stuffs have been determined and reported in this paper. (author)

  6. 137Cs contaminated waste disposal in cement factory: Environmental problems

    In the course of utilization (May-June '91) of aluminum slags polluted by 137Cs at the cement factory Presacementi in Robilante (Cuneo, Italy) and during the following months, samples were taken in particular points of the plant, at fixed frequencies. Samples were analyzed to determine 137Cs concentration. Collected data were used to study the behaviour of the element throughout the process. Emissions and ground level air concentrations were estimated from the available data. Contamination of the manufactured cement were monitored until negligible values of 137Cs concentration were attained

  7. A first attempt to derive soil erosion rates from 137Cs airborne gamma measurements in two Alpine valleys

    Arata, Laura; Meusburger, Katrin; Bucher, Benno; Mabit, Lionel; Alewell, Christine

    2016-04-01

    The application of fallout radionuclides (FRNs) as soil tracers is currently one of the most promising and effective approach for evaluating soil erosion magnitudes in mountainous grasslands. Conventional assessment or measurement methods are laborious and constrained by the topographic and climatic conditions of the Alps. The 137Cs (half-life = 30.2 years) is the most frequently used FRN to study soil redistribution. However the application of 137Cs in alpine grasslands is compromised by the high heterogeneity of the fallout due to the origin of 137Cs fallout in the Alps, which is linked to single rain events occurring just after the Chernobyl accident when most of the Alpine soils were still covered by snow. The aim of this study was to improve our understanding of the 137Cs distribution in two study areas in the Central Swiss Alps: the Ursern valley (Canton Uri), and the Piora valley (Canton Ticino). In June 2015, a helicopter equipped with a NaI gamma detector flew over the two study sites and screened the 137Cs activity of the top soil. The use of airborne gamma measurements is particularly efficient in case of higher 137Cs concentration in the soil. Due to their high altitude and high precipitation rates, the Swiss Alps are expected to be more contaminated by 137Cs fallout than other parts of Switzerland. The airborne gamma measurements have been related to several key parameters which characterize the areas, such as soil properties, slopes, expositions and land uses. The ground truthing of the airborne measurements (i.e. the 137Cs laboratory measurements of the soil samples collected at the same points) returned a good fit. The obtained results offer an overview of the 137Cs concentration in the study areas, which allowed us to identify suitable reference sites, and to analyse the relationship between the 137Cs distribution and the above cited parameters. The authors also derived a preliminary qualitative and a quantitative assessment of soil redistribution

  8. Effect of wood ash and K-fertilization on {sup 137}Cs uptake by selected forest plants

    Mandro, Yrii N. [Zhytomyr State Technological University, P.O. Box 10005 Zhytomyr (Ukraine); Rosen, Klas [Swedish University of Agricultural Sciences P.O. Box 7070 SE-750 07 Uppsala (Sweden); Vinichuk, Mykhailo M. [Zhytomyr State Technological University, P.O. Box 10005 Zhytomyr (Ukraine); Swedish University of Agricultural Sciences P.O. Box 7070 SE-750 07 Uppsala (Sweden)

    2014-07-01

    Accumulation {sup 137}Cs by different forest plants and trees after fertilization of soil with potassium and wood ash ({sup 137}Cs-contaminated and non-contaminated) in forest ecosystems of Ukraine contaminated by radionuclides after Chernobyl accident in 1986 was studied. Experiment is performed in Bazar forestry, Zhytomyr region, Ukraine, located about 70 km (51 deg. 5'35'' N, 29 deg. 18'56'' E) from Chernobyl NPP. Potassium fertilizer (KCl, wooden ash (Ash), and {sup 137}Cs-contaminated ash ({sup 137}CsAsh) in different combinations) were spread on the forest floor in April 2012 at a rate corresponding 100 kg/ha potassium. The experiment layout was as follows: 1- Control (no fertilizers were applied), 2- KCl, 3- Ash + KCl, 4- Ash + {sup 137}CsAsh, 5- Ash, 6- {sup 137}CsAsh + KCl. Samples (leaves and annual shoots) of blueberry (Vaccinium myrtillus), cowberry (Vaccinium vitis-idaea), rowan (Sorbus aucuparia), birch (Betula), buckthorn (Frangula) and oak (Quercus robur) and also mushrooms (fruit bodies of Russula, Lactarius, Cantharellus, Collybia etc.) and berries (blueberry and cowberry) were taken monthly from each treatment. Samples were measured for {sup 137}Cs with calibrated HPGe detectors. The results of the first year studies show variation of Transfer Factors (TF) for different plants and for the same plants on different treatments. The effect of fertilization was found for blueberry on Ash-applicated (TF = 0.0085 ± 0.0025), {sup 137}CsAsh + KCl-applicated (TF = 0.0105 ± 0.0060) and Ash + KCl-applicated (TF = 0.0123 ± 0.0058) treatments compared to Control (TF = 0.0163 ± 0.0092). Also good effect for rowan on Ash + KCl-applicated treatment (TF = 0.0067 ± 0.0024) compared to Control (TF = 0.0100 ± 0.0064). Effect was less obvious for birch on Ash + KCl-applicated treatment and for cowberry on Ash + KCl-applicated treatment. There was not found an obvious effect of fertilization for buckthorn. Positive effect of

  9. Specific and varieties differences between cereals in 137CS and 90Sr accumulation on sod-podzolic loamy sand soil

    Interspecific distinctions on radionuclides accumulation depending on winter, spring wheat varieties and oats, reaching on 137Cs 1,7-3,1 times, on 90Sr - up to 2 times are revealed. Intervarietal distinctions on accumulation 137Cs at a winter wheat-1,7 time, at a spring wheat-1,6 time, at an oats-1,3 time, on accumulation 90Sr at winter wheat-1,1 times, at a spring wheat and at an oats - 1,5-1,6 times are established. Carried out research have allowed to recommend for cultivation in the polluted territories the zoned varieties which to the least degree accumulate radionuclides: a winter wheat - Bylina, Legend, Tsentos; a spring wheat - Kvattro, manu; an oats - Chakal, Dukat and Alph. These varieties can serve as an initial material for the further selection work on varieties breeding, steady against the raised environmental contamination. Varieties cultivation with the least values of factors of transition 137Cs and 90Sr on territories polluted by radionuclides is possible on soils in 1,6 times more polluted, than at varieties cultivation with high parameters of radionuclides transition. Yield, grain quality -protein and gluten was studied. Correlation relationships among transfer coefficients radionuclides 137Cs and 90Sr in grain of varieties, yield and potassium and calcium contents in grain was established

  10. Transfer of 226Ra, 85Sr and 137Cs from milk to milk products

    Transfer of 226Ra, 85Sr and 137Cs from cow and sheep milk to various Syrian dairy products has been evaluated. Dairy products include Kashkivan cheese, braided cheese, Haloom cheese, Sircassian cheese, liquid cheese, native cheese, cottage, thick yogurt, butter and milk cream. The results showed that the percentage of 226Ra, 85Sr and 137Cs transferred from cow milk to milk cream (Pt = food processing retention factor x processing efficiency x 100%) has reached 32%, 16% and 7%, respectively. Butter and liquid cheese were found to have the lowest percentage of transferred 226Ra, 85Sr and 137Cs. Most of the obtained Pt values of the studied radionuclides in thick yogurt were relatively low in spite of the high processing efficiencies of thick yogurt. Moreover, the transfer, Pt, of the studied radionuclides from cow milk to the prepared cheese was higher than those values determined for sheep milk. This is due to differences in chemical compositions of each type of milk. On the other hand, the treatment of Native cheese, most commonly consumed cheese in Syria, with different concentrations of NaCl solutions showed that 137Cs was completely removed from cheese soaking in 5% NaCl solution (soaking time of 48 hours), while 40% of 226Ra and 80% of 85Sr were also decontaminated using 0-2.5% NaCl solutions and soaking time of 48 hours. Based on the obtained results, industrialization processes of the dairy products that resulted the removal of radionuclides have been identified. (author)

  11. Migration of 137Cs and 90Sr in undisturbed soil profiles under controlled and close-to-real conditions

    Migration of 137Cs and 90Sr in undisturbed soil was studied in large lysimeters three and four years after contamination, as part of a larger European project studying radionuclide soil-plant interactions. The lysimeters were installed in greenhouses with climate control and contaminated with radionuclides in an aerosol mixture, simulating fallout from a nuclear accident. The soil types studied were loam, silt loam, sandy loam and loamy sand. The soils were sampled to 30-40 cm depth in 1997 and 1998. The total deposition of 137Cs ranged from 24 to 45 MBq/m2, and of 90Sr from 23 to 52 MBq/m2. It was shown that migration of 137Cs was fastest in sandy loam, and of 90Sr fastest in sandy loam and loam. The slowest migration of both nuclides was found in loamy sand. Retention within the upper 5 cm was 60% for both 137Cs and 90Sr in sandy loam, while in loamy sand it was 97 and 96%, respectively. In 1998, migration rates, calculated as radionuclide weighted median depth (migration centre) divided by time since deposition were 1.1 cm/year for both 137Cs and 90Sr in sandy loam, 0.8 and 1.0 cm/year, respectively, in loam, 0.6 and 0.8 cm/year in silt loam, and 0.4 and 0.6 cm/year for 137Cs and 90Sr, respectively, in loamy sand. A distinction is made between short-term migration, caused by events soon after deposition and less affected by soil type, and long-term migration, more affected by e.g. soil texture. Three to four years after deposition, effects of short-term migration is still dominant in the studied soils

  12. Spatial Distribution of 137Cs in Suface Soil under Different Land Uses in Chao Phraya Watershed: Potential Used as Sediment source Tracing

    Sediment fingerprinting techniques involves the discrimination of sediment sources based on differences in source material properties and quantification of the relative contributions from these sources to sediment delivered downstream to the river catchments. Results of the previous study indicated that fallout radionuclides (FRNs); 137Cs and excess 210Pb (210Pbex) are the most suitable radionuclides to be used as sediments sources tracers. This study investigated the spatial distribution of 137Cs in soil under different land uses in Chao Phraya watershed, the most significant watershed in Thailand. Emphasis was placed on discriminating among potential sediment sources include the cultivated (upland crops), pasture field, uncultivated (swamp, forest, and grass field), and channel erosion (stream and river bank). One hundred and twenty four soil samples were collected from all sources and determining for 137Cs. The 137Cs mass activities in pasture areas varied from the limit of detection (LLD) to 1.22±0.05 with the average of 0.64±0.14 Bq kg-1. In cultivated areas the 137Cs mass activities varied from LLD to 1.41±0.04 with the average of 0.38±0.04 Bq kg-1.The 137Cs mass activities were higher in uncultivated areas varied from 0.12± 0.03 to 1.73 ±0.05 with the average of 0.76±0.15 Bq kg-1. The 137Cs mass activities in channel bank varied from LLD to 1.16±0.04 with the average of 0.39±0.05 Bq kg-1.GIS and geospatial interpolations revealed pattern in the spatial concentrations of 137Cs and indicated important differences in its distributions showing the differences behavior of 137Cs in different land uses.

  13. Accumulation of 137Cs in puddle sediments within urban ecosystem

    The role of puddle sediments as a final depot of 137Cs horizontal migration within the urban landscape is studied using the example of Ekaterinburg city, Russia. Radioactive contamination in the city appeared due to fallout after atmospheric testing of nuclear weapons and nuclear accidents. Contamination density of 137Cs in the region was assessed from archive data to be about 5.1 kBq/m2, of which the maximum activity concentration (137Cs activity concentration in puddle sediments of 80 Bq/kg, with a maximum value of 540 Bq/kg. It is estimated that horizontal migration has led to about a fourfold concentration of 137Cs in puddle sediments.

  14. Considerations on the ICRP model predictions of the transfer of (137)Cs from food to the milk and urine of lactating mothers.

    Giussani, Augusto; Risica, Serena

    2014-06-01

    A recent work has shown that the current ICRP biokinetic model for the transfer of caesium radionuclides from food to human breast milk was able to describe with satisfactory accuracy (137)Cs activity concentrations in human breast samples collected a few weeks after the Chernobyl accident as well as in samples collected some years later. However, systematic discrepancies were observed for the predictions of the activity concentrations in urine samples. In the present work, modifications to the model were investigated with the aim of improving the agreement between model predictions and data. It turned out that the disagreement for the urine data was ascribable to the mathematical simplifications used by the ICRP to describe urinary excretion in the first few days after delivery. However, the predictive performances of the model remained unchanged even when differences in the bioavailability of caesium from the ingested food types were considered or metabolic interactions between caesium and potassium were introduced into the model formulation. PMID:24705367

  15. Considerations on the ICRP model predictions of the transfer of 137Cs from food to the milk and urine of lactating mothers

    A recent work has shown that the current ICRP biokinetic model for the transfer of caesium radionuclides from food to human breast milk was able to describe with satisfactory accuracy 137Cs activity concentrations in human breast samples collected a few weeks after the Chernobyl accident as well as in samples collected some years later. However, systematic discrepancies were observed for the predictions of the activity concentrations in urine samples. In the present work, modifications to the model were investigated with the aim of improving the agreement between model predictions and data. It turned out that the disagreement for the urine data was ascribable to the mathematical simplifications used by the ICRP to describe urinary excretion in the first few days after delivery. However, the predictive performances of the model remained unchanged even when differences in the bioavailability of caesium from the ingested food types were considered or metabolic interactions between caesium and potassium were introduced into the model formulation. (note)

  16. Leaching of 60Co, 137Cs and 226Ra in lysimeter experiments

    The present report describes the first results obtained from lysimeter experiments started in 1990. The lysimeter plant consists of twelve soil monoliths from four different sites (three replicates each). Since 1990 the following agricultural crops were grown: endive, corn, winter wheat, mustard, sugar beet and potato. Gravitational water ranged from 3.9 % to 18.3 % of precipitation plus irrigation water, calculated as half years average values excluding the first six months of operation. The two Cambisols on sediments exhibited a mean percentage of approx. 10 %. The Dystric Cambisol on silicate rock and the Gleysol showed average values of 20 %. In 1990 the top layers (20 cm) were contaminated with three radionuclides. The leaching of the contaminants 60Co, 137Cs and 226Ra differed distinctly between the elements. The lowest leaching rates were observed for 137Cs, followed by 60Co. The 226Ra-concentrations in the gravitational water were clearly highest of all. However, the comparison of the 226Ra/2228Ra ratios in deep soil layers and in gravitational water showed that the 226Ra measured in the leachate originates from the natural contents in the subsoil and not from the artificial 226Ra contamination of the topsoil. The mobility of the artificial radionuclides decreased therefore in the following order: 60Co > (226Ra) > 137Cs. (author)

  17. Migratory capacity of 137Cs in water-containing rocks

    The effects of a number of physicochemical and hydrogeologic factors (sorption capacity of rocks, mechanisms of cesium absorption by these, chemical composition of underground waters) on 137 Cs migration in the case of radioactive contamination of underground water in areas of location of atomic power stations have been studied. Approximate equations of ion-exchange sorption may be applied for predicting 137 Cs migration in rocks within the aeration zone and in water-bearing horizons

  18. /sup 137/Cs radioactive dating of Lake Ontario sediment cores

    Ward, T.E.; Breeden, J.; Komisarcik, K.; Porter, R.; Czuczwa, J.; Kaminski, R.; McVeety, B.D.

    1987-12-01

    The distribution of /sup 137/Cs in sediment cores from Lake Ontario provides estimates of the sediment accumulation rates. Geochronology with /sup 210/Pb dating and distribution of Ambrosia (ragweed) pollen compare well with /sup 137/Cs dating. These methods can determine with precision, changes in sedimentation occurring over the past 100 years or so. Typical sedimentation rates of 0.18-0.36 cm/yr were measured. 16 refs., 3 figs., 2 tabs.

  19. 137Cs radioactive dating of Lake Ontario sediment cores

    The distribution of 137Cs in sediment cores from Lake Ontario provides estimates of the sediment accumulation rates. Geochronology with 210Pb dating and distribution of Ambrosia (ragweed) pollen compare well with 137Cs dating. These methods can determine with precision, changes in sedimentation occurring over the past 100 years or so. Typical sedimentation rates of 0.18-0.36 cm/yr were measured. 16 refs., 3 figs., 2 tabs

  20. Variation of 14C, 137Cs and stable carbon composition in forest soil and its implications

    In Japan, about 70% of land area is covered by forest. Therefore, forest ecosystem plays a vital role in ultimate fate of radionuclides and carbon cycle in terrestrial environment. Three undisturbed forest soil profiles were collected from Ibaraki Prefecture, Japan. The 137Cs data illustrate that maximum fallout deposition of 137Cs took place around 1964. 14C determination shows that 14C also has peak values in the top 10 cm of the soil profiles ascribed to the highest bomb 14C level in 1960's. The 13C data show that the turnover dynamics of soil organic carbon could be described very well by progressive enrichment values of δ13C. (author)

  1. Determination of 40K and 137Cs concentration in selected honey samples

    Seventeen honey samples collected at different sites during 1992 have been measured using the method of γ-spectroscopy. Measurements were performed by a low background high purity germanium spectrometer of a relative efficiency of 14.5% and an energy resolution of 1.7.keV. Using natural γ-ray sources to determine efficiency, it has been shown that out of 17 samples of natural honey only two (of meadow type) have specific activity of 137Cs greater than 0.5 Bq kg-1. The remaining samples have the same 137Cs concentrations as before May, 1986. Predominant activity in all samples comes from the 40K radionuclide, indicating natural honey. (author) 5 refs.; 1 tab

  2. Natural gamma radioactivity and of 137 Cs in soil of the Chimaltitan municipality, Jalisco, Mexico

    With the purpose of determining the activity due to the natural presence of the 226 Ra, 232 Th, 40 K and 137 Cs in soil samples, of the municipality of Chimaltitan Jalisco. A set of these samples was measured in a gamma ray spectrometric system based on a High-purity Germanium detector. It is well-known that approximately 87% of the dose of the received radiation by the population is due to sources of natural radiation and 13% of the anthropogenic radiation. The gamma radiation comes mainly from the 40 K and of those radionuclides of the series of radioactive decay of 238 U and 232 Th that its find dispersed thoroughly in the terrestrial crust. In this work its were analyzed twenty-two soil samples. It is enlarged the activity characterization for the radioisotopes of 226 Ra 232 Th, 40 K and 137 Cs. (Author)

  3. Advantages and limitations of 137Cs, 210Pb and 7Be methodologies for assessing erosion and sedimentation processes

    As demonstrated by around 4000 research papers published, fallout radionuclides 'FRN' (137Cs, 210Pb and 7Be) have been successfully used as soil redistribution tracers for measuring erosion and sedimentation processes. A table presents the advantages and limitations of each of the FRNs as soil redistribution tracers

  4. 137Cs determination and mutagenicity tests in wild Mus musculus domesticus before and after the Chernobyl accident

    Wild rodents were collected alive in a suburban area to the north of Rome before, during, 6 months and 1 year after the Chernobyl accident. Radionuclide determinations to assess their content of 137Cs and mutagenicity tests (bone-marrow micronucleus test and sperm abnormalities assay) were performed on the captured animals. The results obtained for the species Mus musculus domesticus (which was the rodent captured in highest numbers), compared with the results obtained before the fallout, showed an increase of both micronucleated polychromatic erythrocytes (MPCEs/1000 PCEs) and 137Cs content during and after the fallout. (author)

  5. Distribution of 137Cs in water leachates of forest humus

    The distribution of 137Cs in water extracts of organic layers of forest soils was investigated using an ultrafiltration method. Samples were taken from two sites in the Bavarian Alps. The different horizons of the organic layers were extracted by column elution with water and 50 mmol/litre CsCl solution. Water extracts were fractionated using membranes with the molecular weight cutoff of 500, 1000 and 3000 Dalton to determine the molecular weight distribution of dissolved organic carbon (DOC). The activity of 137Cs associated with the different DOC-fractions was measured by direct gammaspectrometry. Cesium-137 in the fraction smaller than 500 Dalton was defined as 'ionic'. The results indicated a change of the binding sites depending on the degree of decomposition and humification in the profile. Organic bound 137Cs was identified in all extracts. High mobilities of DOC and 137Cs were observed in the same horizons, fractionation showed then low-molecular-weight DOC and 137Cs mainly in ionic form. In horizons with high-molecular-weight DOC the portion of organic bound 137Cs ranged up to 40%. (author)

  6. Estimation of erosion rate using natural isotop 137Cs

    The investigation of erosion rate using natural isotope 137Cs had been done in hilliness area at GOULBURN-NWS-Australia. The presentation of 137Cs in natural was as a result of nuclear weapon testing in the middle of 1950's. Fallout of 137Cs input, when it reached the ground, it rapidly adsorbed at the soil. 137Cs bind very strong at the fine soil, so it can be used as tracer in the study of soil movement. Soil samples were taken using coring device (di=10 cm, h=20 cm), and were brought to laboratorium for short commun analysis. The preparation are drying, weighing, crushing and sieving. The 137Cs content of fine samples that pass the 1 mm sieve were analyzed using gamma-spectrometer. The total erosion rate was calculate by ploting the 137Cs values in the topography map of study area. The result showed that erosion was very low, and total erosion rate is 130 kg/ha.y. (authors)

  7. Transfer of 137Cs through the food chain to man

    Deposition, concentrations in diet, and body burdens of 137Cs have been measured since 1954 at various sites throughout the world. This report is a compilation and updating of various fallout 137Cs measurements and an interpretation of transfer properties of 137Cs from deposition to diet and from diet to man. An empirical model is used to correlate deposition and diet data. Direct foliar contamination, stored food supplies, and uptake from soil contribute to the dietary levels of 137Cs. The accumulation of 137Cs by man is described by a single exponential model. The inferred biological half-times, 200 to 400 days, are somewhat greater than the half-time of about 100 days obtained from shorter term studies. Differences in body burdens due to sex, age, and weight are discussed. During the period 1954 to 1974, the internal dose from fallout 137Cs, based on average body burdens, is estimated to be 4 to 5 percent of the 21 year radiation dose from 40K

  8. Specific activity 137Cs at fishes of Ukraine current state

    Specific activity of 137Cs at fishes of reservoirs of 30 kilometers ChNPP zone (Pripyat river and its bays, lakes, cool-ing-pond of ChNPP, etc.), water basins of Dneprovsky cascade, Shatsky lakes and Black sea near town Sudak is investigated during 2010 - 2012. Levels of specific activity of 137Cs at fishes in many respects are defined by flowage of the reservoir. Normally, the flowage of the reservoir is more, the levels of specific activity of 137Cs at fishes are less. The greatest specific activity of 137Cs at fishes was registered in the north of Ukraine in closed and half-closed reservoirs of 30 kilometers ChNPP zone - to 32000 Bqk/kg. In the southern direction activity of 137Cs at fishes decreases from 4,8 to 78,5 Bq/kg in Kyiv water basin to 1 - 6 Bq/kg, in the Kahovsky water basin and to 0,6 - 1,9 Bq/kg in the Black sea. In large reservoirs the greatest specific activity of 137Cs, as a rule, is registered in fishes of the higher trophic levels

  9. Influence of soil properties on 137Cs and 90Sr sorption in the environment of west coast of India

    Detailed studies on distribution of 137Cs and 90Sr in the environs of South West Coast of India were carried out. The study was primarily aimed at finding the reason for the observed higher concentration of 137Cs in Kaiga region and also to establish the baseline data on 137Cs and 90Sr concentrations in the soil of Coastal Karnataka and Goa regions. The influence of soil pH, density, silt, clay, sand and organic matter contents on the retention of these radionuclides in the surface soil (0-5 cm) were studied. The 137Cs inventory was found to vary in the range -2 with a mean value of 1104 Bq m-2 and that of 90Sr varied in the range -2 with a mean value of 88.1 Bq m-2 in the region. The observed higher 137Cs concentration is traced to heavy rainfall and higher organic matter content and lower pH of the soil. (author)

  10. Synthesis of new greener biopolymer chitosan based hydrogel and its application for separation of 152Eu and 137Cs

    A chitosan based hydrogel has been synthesised followed by its characterization by IR, swelling study and TGA. The hydrogel was used for separation of long-lived radionuclides such as 152Eu and 137Cs using solid liquid extraction (SLX) technique. Separation of 152Eu and 137Cs was carried out using various concentration of HCl (10-5 to 1 M) against 0.1 g of hydrogel as solid phase. At typical experimental condition maximum adsorption of 152Eu into the solid phase was 87% without any contamination of 137Cs. In desorption study of solid phase containing 152Eu, about 72% of 152Eu was extracted into liquid phase from solid hydrogel phase in a single run. (author)