共查询到20条相似文献,搜索用时 46 毫秒
1.
Nao Kamei-Ishikawa Keiko Tagami Shigeo Uchida 《Journal of Radioanalytical and Nuclear Chemistry》2011,290(2):247-252
Plant uptake of radiocesium (137Cs) was investigated in consideration of the relationships with naturally existing 133Cs and potassium (K). We first determined plant-unavailable fraction of 137Cs in soil by batch sorption and sequential extraction methods with a radiotracer. Then, using the data obtained from the
batch sorption and extraction methods, we clarified the relationships of plant-available and plant-unavailable fractions between
137Cs, 133Cs, and K in soil. Additionally, 137Cs concentrations in crop were estimated using 137Cs in soil and several factors, i.e. fixation ratio of 137Cs in soil, cation exchange capacity, and K concentration in crop. The results implied that the fixation ratio of 137Cs in soil was a very important key to understanding 137Cs plant uptake. 相似文献
2.
S. Osaki S. Sugihara Y. Maeda T. Osaki 《Journal of Radioanalytical and Nuclear Chemistry》2007,272(1):135-140
Depth distribution of atmospheric 210Pb and 7Be and 90Sr and 137Cs fission products was measured in two types of aeolian soils (desert dust and volcanic ash), irrigated paddy soil and strongly
acidic soil. The depth dependence of 210Pb, 7Be and 137Cs show that these radionuclides have been diffused as solid soil particles in surface soil layers. In aeolian soil layers,
about 50% of 90Sr were diffused in surface soil layer and the remaining 50% had penetrated to deeper layers. The half of the fission particles
containing 90Sr were shown to have decomposed over the past 35 years. 相似文献
3.
D. Mascanzoni 《Journal of Radioanalytical and Nuclear Chemistry》2009,282(2):427-431
The radioactive contamination following the Chernobyl accident resulted in high concentrations of 137Cs in several mushrooms species. Mushroom samples were collected in a forest environment between 1986 and 2007 and the transfer
of 137Cs to two edible species, Suillus variegatus and Cantharellus spp., was investigated. The 137Cs uptake by the collected samples did not decrease over time and in Cantharellus spp. a significant increase was observed. Most of the 137Cs in soil still appears to be available for uptake and radioactive decay of the radionuclide is likely the main factor for
the reduction of 137Cs in a forest ecosystem. 相似文献
4.
N. Momoshima M. Sayad M. Yamada M. Takamura H. Kawamura 《Journal of Radioanalytical and Nuclear Chemistry》2005,266(3):455-460
Summary Global fallout levels of 99Tc and 137Cs of surface seawater in the Pacific Ocean were measured. The 99Tc concentrations ranged from 0.62 to 3.33 mBq. m-3and 5 of 6 samples showed less than 1 mBq. m-3except one sample taken in the Great Barrier Reef, Australia. The 137Cs concentrations ranged from 2.13 to 3.14 Bq. m-3, showing a gradual decrease in the North Pacific toward the equator and a constant level in the South Pacific. The 99Tc/137Cs activity ratios ranged from 2.5. 10-4to 2.9. 10-4, which is very close to that calculated theoretically from the fission yield. 相似文献
5.
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. 相似文献
6.
S. M. Pan Y. H. Xu A. Wang P. P. Povinec 《Journal of Radioanalytical and Nuclear Chemistry》2012,292(3):1207-1214
It has been generally accepted when estimating sedimentation rates using the 137Cs dating method that the position of the 137Cs maximum in a sediment profile represents the year 1963. In this paper we validated this approach by developing a model
in which the annual 137Cs global fallout flux for the Yangtze River estuary was established on the basis of the Tokyo flux corrected for precipitation
rates observed in Shanghai. As the 137Cs maxima in the sediment deposition profiles depend on the sedimentation rates, the sub-sampling intervals were calculated
accordingly. Higher measured than the calculated values were found in some cores, what may be due to fluctuating sedimentation
rates and an additional deposition of 137Cs from land-based sources. The study provides useful information on the reliability of the measured 137Cs maxima in sediment profiles frequently used for dating of sediments in marine (coastal regions, open seas) as well as in
terrestrial (lakes) environments. 相似文献
7.
The cumulative depositions of137Cs,90Sr and fallout Pu in the volcanic ash soil of Korea were determined. The average accumulated depositions of137Cs,90Sr and fallout Pu in the volcanic soil were much higher than those in other forest sites of Korea. From depth profiles, it
was found that137Cs,90Sr and239,240Pu in the volcanic soil are more mobile than those in other forest sites of Korea, and that the downward movement of90Sr is faster than137Cs and239,240Pu. A significant correlation was found between the concentration of137Cs and those of90Sr and239,240Pu. The activity ratios of238Pu/239,240Pu and241Pu/239,240Pu in soils are close to those observed in the cumulative deposit from the global fallout of nuclear weapon testings. 相似文献
8.
A. H. Al-Rayyes M. Al-Oudat A. Al-Hamwi H. Mukhallalati 《Journal of Radioanalytical and Nuclear Chemistry》2007,274(1):139-143
The experiment aimed to evaluate the vertical migration of 134Cs, 90Sr and 238Pu in the main types of Syrian soils; entisol, inceptisol, alluvial (rock outcrops) and gypsiferous soils, using soil columns
through which the aqueous solution of the radionuclides percolated. The results show that the vertical migration of the studied
radionuclides through the soil profile depend on the radionuclide and the soil type. More than 97% of 134Cs and 238Pu concentrated in the upper 2 cm of the entisol, inceptisol, and alluvial soils, whereas only 46.2% to 68.6% of the 90Sr was retained in the upper 2 cm of these soils. The vertical migration of the studied radionuclides in the gypsiferous soil
was different from the other soils. The distribution of the radionuclides in the gypsiferous soil was irregular through the
soil profile and reached the deeper layer of the soil. This may be due to its physical characteristics; poor structure stability,
high permeability and low retention capacity. 相似文献
9.
Determination and spatial distribution of <Superscript>137</Superscript>Cs in soils,mosses and lichens near Kavanayen,Venezuela 总被引:1,自引:0,他引:1
J. J. LaBrecque P. R. Cordoves 《Journal of Radioanalytical and Nuclear Chemistry》2007,273(2):401-404
The activity of 137Cs was determined in soils, mosses, lichens and other vegetation along the Caruay River and near the town of Kavanayen. The
range of values for the soils was from <1.2 Bq·kg−1 of 137Cs (our detection limit) to 14.1 Bq·kg−1. The range of 137Cs activities in the mosses ranged from 9.9 to 17.9 Bq·kg−1 with a mean value of 13.4±4 Bq·kg−1; all the moss samples were found along the river. While the 137Cs activities in the lichens ranged from 9.1 to 29.8 Bq·kg−1; the two values along the river were about three factors higher than the one near Kavanayen. It was concluded that the 137Cs activities in the soils, mosses and lichens are much higher along the river in respect to the nearby town of Kavanayen. 相似文献
10.
J. J. LaBrecque J. A. Alfonso P. R. Cordoves 《Journal of Radioanalytical and Nuclear Chemistry》2008,277(2):405-411
As a result of routine soil sampling to determine the 137Cs background activities country-wide in Venezuela, it was decided to further investigate El Mirador (Lookout) area at the
base of the Sierra de Lema mountain range. In April 2003 (A), soil samples were collected at eight sites on and around the
edge of the diabase outcrop to confirm that this area had anomalously high 137Cs activities. In July 2003 (B), not only soil samples were collected again, but also black mat, palm tree leaves and trunks,
fruit bushes leaves and its fruit and fern leaves. The 137Cs content was measured by high resolution gamma-ray spectroscopy by a comparative method with reference materials. The 137Cs activity values range from 16.3 to 30.8 Bq·kg-1 in the soil samples collected in July 2003, 20.7–32.1 Bq·kg−1 for the black mat, 26.3–38.4 Bq·kg−1 for the palm leaves, 16.8–31.2 Bq·kg−1 for the palm trunks and 17.6–27.3 Bq·kg−1 for the fruit bush leaves, while, the 137Cs activity values for the whole fruit were between 23.4 and 30.7 Bq·kg−1; but, the value of the 137Cs activity in the center of the fruit (the edible part) was 51.6 Bq·kg−1, and the value of the 137Cs activity for the fern leaves was 51.8 Bq·kg−1. Thus, most of the 137Cs activity values determined in the soil, black mat and vegetation samples from El Mirador (Lookout) were considered anomalously
high with respect to those found near the equator and in other areas of Venezuela. Only the center of the fruit from the Clusia grandiflora bushes and the fern leaves had high activity ratios, about a factor of three and could be considered as biomonitors that
concentrate and retain the 137Cs. Finally, these anomalously high 137Cs activities have been attributed not only to the rich organic soils, as sinks, but also due to the affect of the cloud forests. 相似文献
11.
Rajesh H. Panchal D. D. Rao Bipin H. Mehta A. Baburajan Ravindra H. Gaikwad 《Journal of Radioanalytical and Nuclear Chemistry》2012,292(1):401-409
The paper deals with the transfer factors (TF) generated for a few varieties of leafy vegetables (spinach, fenugreek, and
amaranths) consumed by the locals around Tarapur atomic power station environment in India. The soil and leafy vegetable samples
collected from the ambient environment of nuclear site were used for the determination of the TFs and they were compared with
TFs generated from pot experiments under controlled conditions for 137Cs. The activity of 137Cs in soil and each vegetable was determined by gamma spectrometry using HPGe detector (35 and 160% relative efficiency) and
was reported on dry weight basis for both ambient environment and pot samples. The radioactive effluent containing 137Cs (pH ~7) from nuclear power station was used to spike the soil for pot (size 90 cm × 45 cm × 42 cm) experiment. The TFs
obtained for ambient environment and pot experiment were found to be in the range of 0.035–0.592 and 0.0054–0.29, respectively.
It is observed that TFs of ambient environment are in good agreement with those obtained in the pot experiment conducted under
controlled conditions. Further, the observed TF values at Tarapur nuclear site are comparable with the range of typical IAEA
transfer factor values for general leafy vegetation (0.11–2.9) for tropical environment. 相似文献
12.
M. Liezers O. T. FarmerIII M. L. Thomas 《Journal of Radioanalytical and Nuclear Chemistry》2009,282(1):309-313
The measurement of fission product cesium isotopes 135Cs and 137Cs at low femtogram (fg) 10−15 levels in ground water by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) is reported. To eliminate the natural barium
isobaric interference on the cesium isotopes, in-line chromatographic separation of the cesium from barium was performed followed
by high sensitivity ICP-MS analysis. A high efficiency desolvating nebulizer system was employed to maximize ICP-MS sensitivity
~10 cps/fg. The three sigma detection limit for 135Cs was 2 fg/mL (0.1 μBq/mL) and for 137Cs 0.9 fg/mL (0.0027 Bq/mL) measured from the standard with analysis time of less than 30 min/sample. Cesium detection and
135/137 isotope ratio measurement at very low femtogram levels using this method in a spiked ground water matrix is also demonstrated. 相似文献
13.
Tarja Katri Ikäheimonen Iisa Outola Vesa-Pekka Vartti Pekka Kotilainen 《Journal of Radioanalytical and Nuclear Chemistry》2009,280(2):419-425
The Baltic Sea is ecologically unique as one of the world’s largest brackish water basins. It was significantly contaminated by radioactivity following the Chernobyl accident in 1986, the major contaminant being long-lived 137Cs. Due to the slow exchange of water between the Baltic Sea and the North Sea and the relatively rapid sedimentation rates, radionuclides have prolonged residence times in the Baltic Sea. 137Cs levels are consequently still clearly higher than in other water bodies around the world. In addition to the Chernobyl accident, artificial radionuclides in the Baltic Sea originate from the global fallout following nuclear weapons testing in the 1950s and 1960s, while discharges into the Baltic Sea from nuclear power plants and other facilities are of minor importance. Here, inventories and the temporal evolution of radionuclides both in seawater and sediments of the Baltic Sea are presented and discussed. 相似文献
14.
N. M. Antovic V. Popovic I. Antovic N. Svrkota P. Vukotic 《Journal of Radioanalytical and Nuclear Chemistry》2011,290(1):81-88
A coincidence method for measuring 137Cs, 40K, 226Ra and 232Th decay products activity in soil, vegetation and fish samples, was applied to the six-crystal gamma-coincidence spectrometer
PRIPYAT-2M. In this way, some problems appeared in simultaneous measurement of 137Cs, 226Ra and 232Th by NaI(Tl) detectors and the PRIPYAT-2M spectrometer were solved. The obtained results were agreeable with the HPGe spectrometer
ones. 相似文献
15.
Studies of 137Cs distribution in East Malaysia were carried out as part of a marine coastal environment project. The results of measurements
will serve as baseline data and background reference level for Malaysia coastline. Twenty-one locations were identified along
the coastline of East Malaysia, and from each location water samples were collected at the surface of the seawater. Ten near-shore
locations were also selected and seawater was collected at three different depths. Large volumes of seawater were collected
and the co-precipitation technique was employed to concentrate cesium. A known amount of 134Cs tracer was added as yield determinant, followed by addition of copper(II) nitrate salt and a solution of potassium hexacyanoferrate(II)
trihydrate, to precipitate the total cesium. The precipitate slurry was oven dried at 60 °C for 1–2 days, finely ground and
counted using gamma-ray spectrometry. The activity of 137Cs was determined by measuring the peak area under the photopeak of the gamma-spectrum at 661 keV, which is equivalent to
gamma-intensity corrected for detection efficiency, percentage of gamma-ray abundance of the radionuclide and recovery of
134Cs tracer. There were no significant differences of 137Cs activities both in surface and bottom water samples at 95% confidence level. The activity of 137Cs (for all samples) was found to be in the range of 1.47 to 3.36 Bq/m3 and 1.69 to 3.32 Bq/m3 for Sabah and Sarawak, respectively. 相似文献
16.
L. Popov G. Mihailova I. Naidenov 《Journal of Radioanalytical and Nuclear Chemistry》2010,285(2):223-237
The origins of different artificial radionuclides found in soils from Northern and Southern Bulgaria was determined by measurements
of their actual concentrations and respective ratios. On the basis of the measured mobility and concentrations of the investigated
radionuclides in soils, it was estimated that after the Chernobyl accident the mean depositions of fresh 137Cs were 3.0 ± 2.5 kBq/m2 for Northern Bulgaria and 15 ± 7 kBq/m2 for Southern Bulgaria. As a result of global fallout following atmospheric nuclear weapon tests in the 1950s, mean depositions
(corrected to 1965) were calculated for Northern and Southern Bulgaria as follows: for 90Sr—1.0 ± 0.5 and 2.3 ± 1.3 kBq/m2, 238Pu—1.3 ± 0.8 and 2.8 ± 1.6 Bq/m2, 239+240Pu—15 ± 14 and 47 ± 38 Bq/m2, and 241Pu—520 ± 200 and 760 ± 260 Bq/m2. 相似文献
17.
K. Hirose M. Aoyama Y. Igarashi K. Komura 《Journal of Radioanalytical and Nuclear Chemistry》2008,276(3):795-798
137Cs in seawater is one of the most powerful tracers of water motion. Large volumes of samples have been required for determination
of 137Cs in seawater. This paper describes improvement of separation and purification processes of 137Cs in seawater, which includes purification of 137Cs using hexachloroplatinic acid in addition to ammonium phosphomolybdate (AMP) precipitation. As a result, we succeeded the
137Cs determination in seawater with a smaller sample volume of 10 liter by using ultra-low background gamma-spectrometry in
the Ogoya underground facility. 137Cs detection limit was about 0.1 mBq (counting time: 106 s). This method is applied to determine 137Cs in small samples of the South Pacific deep waters. 相似文献
18.
L. I. Tsikritzis 《Journal of Radioanalytical and Nuclear Chemistry》2005,264(3):651-656
Summary The distribution and origin of 40K, 226Ra, 228Ra and 137Cs has been investigated in trees, mosses and lichens in the basin of the West Macedonia Lignite Centre. In tree leaves 137Cs is negligible, while the 226Ra and 228Ra concentrations are affected by the fly ash particles. Concerning 226Ra and 228Ra values of mosses and lichens, which are systematically larger than those of unpolluted areas, the application of chemometrics proved that they originate mainly from the lignite fly ash. 相似文献
19.
Chih-Yu Chiu Shu-Yin Lai Chih-Jung Wang Yu-Ming Lin 《Journal of Radioanalytical and Nuclear Chemistry》1999,239(3):511-515
The distribution of137Cs in an undisturbed, multistoried, subtropical wet montane forest ecosystem surrounding Yuanyang Lake (lake surface level
ca. 1670m, in northeastern Taiwan), was investigated. The mossy forest here represents a currently-rare perhumid temperate
environment in subtropical region. The radioactivity concentration of137Cs was determined by γ-spectroscopy with a Ge(Li) detector. Although the soil is extremely acidic (pH 3.3 to 3.6) and the
rainfall is high,137Cs is evidently retained in the organic layer. The radioactivity concentration of137Cs in surface soil ranges from 28 to 71 Bq·kg−1. The concentrations of137Cs in the ground moss layer and litter were much lower than that in the soil organic layer, this suggests that137Cs detected is not from the newly deposited radioactive fallout. The radioactivity concentration and transfer factor (TF)
of137Cs varied with plant species. Shrubs and ferns have higher values than a coniferous tree (Taiwan cedar). The TF in this ecosystem
is as high as 0.21 to 1.88. The high values of TF is attributed to the abundance of the organic matter in the forest soils.
The rapid recycling of137Cs through the soil-plant system of this undisturbed multistoried ecosystem suggests the existence of an internal cycling
that help the accumulation of137Cs in this ecosystem. 相似文献
20.
I. Lovrencic M. Volner D. Barisic M. Popijac N. Kezic I. Seletkovic S. Lulic 《Journal of Radioanalytical and Nuclear Chemistry》2008,275(1):71-79
Distribution of 137Cs, 40K and 7Be in tissues of the silver fir-tree was studied. Samples of the shoots were taken at six locations in Croatia during five
years. Shoots were cut according to the year of growth and analyzed. Distribution between needles and twigs was also studied.
Samples of the tree rings and the bark were taken at three locations. 137Cs and 40K showed very similar distributions. 137Cs and 40K activities were age-dependent and increased in decreasing age of twigs and needles. The highest activities were measured
in the youngest twigs. The highest 7Be activities were found in the twigs. 相似文献