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1.
The238Pu,239,240Pu and137Cs concentrations in sediments and shore deposition samples of the Vltava river were determined.239,240Pu and137Cs concentrations in sediment samples (five locations) ranged from 19.6 to 124.8 mBq·kg−1 and from 1.8 to 28.2 Bq·kg−1, respectively. The238Pu,239,240Pu and137Cs concentrations in shore deposition samples (four locations) ranged from 2 to 16.8, from 26.8 to 477.2 mBq·kg−1, and from 1.6 to 86.3 Bq·kg−1, respectively. The superficial activity of studied radionuclides in shore deposition areas was determined and radionuclide origin at studied locations was discussed.  相似文献   

2.
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   

3.

Radioactivity measurements were performed, at the east (Georgia) and west (Romania) part of the Black Sea, for natural radionuclides and 137Cs in collected water and sediment samples using lab-based and in situ gamma-ray spectrometry. The activity concentrations of 137Cs at Georgian area in the sediment and seawater ranged between 20 to 50 Bq kg−1 and 8 to 25 Bq m−3, respectively while at the Romanian area the activity concentration ranged from 10 to 30 Bq kg−1 and 3 to 15 Bq m−3, respectively. The activity concentration values of 7Be at the Georgian area reached values up to (30 ± 4) Bq kg−1. The induced dose rates to marine organisms in both areas estimated by the ERICA assessment tool were much lower than the screening value of 10 μGy h−1.

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4.
Summary Radionuclide (137Cs, 238U, 232Th and 40K) concentrations were determined in a sediment trap and bottom sediment samples collected from a station at the eastern Turkish coast of the Black Sea. The specific activity of the 137Cs radionuclide in the settling particles ranged from 0.04±0.01 to 0.10±0.02 Bq. g-1dry weight. The calculated flux rate of the 137Cs was between 0.37 and 2.59 Bq. m-2. d-1in the sampling periods of 2002 and 2003. The 137Cs concentration in the bottom sediment profile were between 0.039±0.013-9.083±0.017 Bq. g-1dry weight in the same station. The vertical profile of the radionuclides suggests that they have little mobility during the 17 years after the Chernobyl accident.  相似文献   

5.
137Cs was measured in soil samples collected in Korea from 2006 to 2008 using a low-level background gamma-ray spectrometer that was designed and developed by KRISS (Korea Research Institute of Standards and Science). The objectives of this study are to evaluate the newly developed low-level background gamma-ray spectrometer and, consequently, to provide information on the horizontal and vertical distribution of 137Cs in Korean soil. 137Cs concentrations in surface soil varied from 12.8 ± 0.9 to 108 ± 4 Bq kg?1, and the vertical profiles of 137Cs from the Nari basin in Ulleung Island in the East Sea/Sea of Japan and Seongsan Ilchulbong Peak, Jeju Island, showed a higher concentration in the surface layer that gradually decreased with depth. On the other hand, the 137Cs concentration in soil samples collected from Bukhan Mountain National Park in Seoul showed a subsurface maximum and decreased with depth. The 137Cs inventories in the soil column were calculated to be 1,830–4,360 Bq m?2 with a mean of 2,770 Bq m?2, which was the same order of magnitude as the global fallout inventories in the mid-latitude region of the Northern Hemisphere.  相似文献   

6.
In this article, we present results obtained from a radiometric survey that was conducted in the Leepa Valley of Azad Jammu & Kashmir, Pakistan. The purpose of current study is to appraise the radioactivity levels and the associated health hazards due to the terrestrial radionuclide in soil and rock samples. In this regard, 16 soil and 17 rock samples were collected from different locations of the Leepa Valley. After processing the samples, activity concentrations of primordial (232Th, 226Ra and 40K) and anthropogenic (137Cs) radionuclides were determined using a P-type coaxial high purity germanium detector. From the results obtained the mean activity concentrations of radionuclides 226Ra, 232Th and 40K in the soil samples were found to be 31.25 ± 0.46, 44.1 ± 1.07 and 575 ± 8.89 Bq kg?1 respectively. Whilst, in rock samples 226Ra, 232Th and 40K mean activities were found as 28.46 ± 0.45, 48.63 ± 1.12 and 666.7 ± 9.39 Bq kg?1, respectively. The 137Cs concentration level in soil and rock samples is found to be 15.04 ± 0.29 and 5.7 ± 0.16 Bq kg?1, respectively. The average radium equivalent activity (R aeq) was found as 143.16 and 142.93 Bq kg?1 in soil and rock samples, respectively. These findings are less than the recommended safe value of 370 Bq kg?1 as given in OECD report (1979). The values of external (H ex) and internal hazard index (H in) are also less than unity. Mean value of absorbed dose rate was found as 69.78 nGy h?1 for the soil samples, which is in good agreement with the world wide average value (70 nGy h?1). Mean value of absorbed dose rate from rock samples was found as 70.01 nGy h?1. Mean values of the annual effective dose is also lower than the values reported for different other countries of the world.  相似文献   

7.
In 2002, an extensive study was performed in forest sites of Izmir. This first study results led on the one hand, to quantify of 137Cs and 40K concentration in mushrooms collected in the Izmir region and to a first evaluation of dose in people due to the ingestion of radionuclide-contaminated mushrooms. The mushroom concentration values varied over a wide range from below detection limit to 401 ± 4 Bq kg?1 (dry wt) for 137Cs. The 40K concentration values obtained for different species of mushrooms ranged from 588 ± 26 Bq kg?1 to 2024 ± 63 Bq kg?1 (dry wt). The annual effective dose values due to mushroom ingestion for 137Cs are lower than the ICRP-2007’s reference level value of 1 mSv for “existing” exposure situation. Inductively coupled plasma-mass spectrometry was used to measure many alkali–alkaline earth elements and heavy metals in mushroom samples. The relationships among the concentrations of 137Cs and the stable elements were presented and the occurrence of metals in mushrooms was evaluated.  相似文献   

8.
Mumbai Harbour Bay (MHB) is a recipient of low level treated effluents from BARC, Trombay and its also a recipient of domestic and industrial wastes from the city of Mumbai and adjoining areas. Sediment samples were collected from various locations of MHB to determine the concentrations of naturally occurring radionuclides like 226Ra, 228Ra and 40K which varied between 4.0 and 26.0, 5.5 and 19.9, 249.6 and 557.6 Bq kg (dry) ?1 respectively and are comparable to the worldwide average concentration. The mean value ratio of 228Ra/226Ra in sediment was found to be 1.4, indicating a relatively higher mobility of 238U compared to 232Th. The concentration of anthropogenic radionuclide 137Cs in sediment and biota ranged between 3.6 and 54.5 Bq kg (dry) ?1 , <0.08 and 0.5 Bq kg (wet) ?1 respectively. The ingestion dose to ‘General Public’ due to 137Cs intake is 0.02 μSv years?1 which is negligible compared to the internationally accepted limit of 1,000 μSv years?1 to ‘members of public’.  相似文献   

9.
Methodologies for analysis of anthropogenic and natural radionuclides in marine samples were developed and applied in environmental samples. Results of systematic measurements of these radionuclides have showed that artificial radioactivity levels are in agreement with the values from the regions not affected directly by nuclear accidents or nuclear reprocessing plant discharges and are due to the global fallout. The average concentration of137Cs is of 1.4 Bq·m−3 in seawater, ranges from 13 to 220 mBq·kg−1 in fish, and from 0.4 to 1.8 Bq·kg−1 for sediments.90Sr levels in seawater are of 1.8 Bq·m−3 and in fish vary from 19 to 75 mBq·kg−1. Sediments present concentrations of90Sr lower than 0.8 Bq·kg−1 and for239+240Pu of 0.03 to 0.18 Bq·kg−1.210Po levels in fish range from 0.5 to 5.3 Bq·kg−1. The data generated represent reference values for our country and are used to estimate the intake levels of these radionuclides by consuming of marine products.  相似文献   

10.
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.
Determining radioactivity levels in foodstuffs is of great importance for the protection of human health. In addition, the literature includes few studies related to this subject in Turkey. In this study, gamma spectroscopic system was used in order to measure 226Ra, 232Th, 40K and 137Cs activity concentrations in vegetables and fruits produced in Elaz?? Region. The average activity concentrations in vegetables was calculated as 0.64 ± 0.26 Bq kg?1 for 226Ra, 0.65 ± 0.14 Bq kg?1 for 232Th, 13.98 ± 1.22 Bq kg?1 for 40K, and 0.54 ± 0.04 Bq kg?1 for 137Cs. The average activity concentrations in fruits were 1.52 ± 0.34, 0.98 ± 0.23, 18.66 ± 1.13 and 0.59 ± 0.16 Bq kg?1, respectively for 226Ra, 232Th, 40K and 137Cs. Total committed effective dose value was determined as 20 and 30.55 μSv y?1, respectively for vegetables and fruits. The findings were compared with previous data reported for Turkey and other regions of the world.  相似文献   

12.
The aim of this study was to determine the level of radionuclide concentration in sediment cores in two different water ecosystems; one closed and one open. Based on this data the changes in these ecosystems were interpreted. Two sediment cores from the Dobczyce reservoir and the Smreczynski Staw Lake were collected and divided into 1 cm thick sub-samples. The samples were air dried and homogenized. The 137Cs and 210Pb (210Pbsup, 210Pbtotal, 210Pbuns) concentrations were measured using gamma and alpha spectrometry. Results showed that the 137Cs concentration in the Dobczyce reservoir is lower than in the Smreczynski Staw Lake. Total 210Pb concentration in the Dobczyce reservoir was around 70 Bq kg?1 and in the Smreczynski Staw Lake was about 500 or 1,200 Bq kg?1 with the decreasing tendency in the sediment core. Sediments are very important constituents of water ecosystems. In spite of the young age of the Dobczyce reservoir, the 137Cs and 210Pb radionuclides were very useful in understanding of the processes which have taken place in these ecosystems. The estimated sedimentation rate indicated such processes as regular sedimentation, mixing of sediments or floods. In the Smreczynski Staw Lake the changes have reflected the changes which took place in the Tatra Mountains.  相似文献   

13.
Radionuclides such as 131I, 134Cs, 137Cs, and 239,240Pu in Korean rainwater have been analyzed by Korea Research Institute of Standards and Science (KRISS) since the Fukushima nuclear power plant accident in March 2011 to investigate the activity level, distribution pattern, and temporal variation and to assess the radiation dose the public is exposed to. The concentration of 131I in the Korean rainwater samples varied between 0.033 (minimum detectable activity; MDA) and 1.30 Bq kg?1 and the concentrations tended to decrease exponentially with time. The concentrations of 134Cs and 137Cs in rainwater ranged from 0.01 to 334 ± 74 and 0.29 ± 0.01 to 276 ± 1 mBq kg?1, respectively. The mean activity ratio of 137Cs/134Cs in the rainwater samples collected from April 18 to May 12 was estimated to be 0.44 ± 0.21, and this value is lower than that (ca. 1) observed in Fukushima, Japan, when there was an escape from the nuclear reactors. When an attempt was made to analyze Pu isotopes in rainwater samples, no Pu isotopes were detected above the MDA in any of the rainwater samples. Although the locations investigated were different from Asia to Europe, the concentrations of 131I, 134Cs and 137Cs in the rainwater are comparable, which suggests a global contamination of 131I, 134Cs, and 137Cs occurred because of the Fukushima nuclear power plant accident.  相似文献   

14.
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·kg–1 dry weight. The range of the 137Cs concentration in anchovy fish muscles were found between 4±2 – 10±5 Bq·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·kg–1 dry weight. The concentrationsof 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.  相似文献   

15.
Concentrations of 238U, 232Th, 226Ra, 40K and 137Cs are measured in collected soil samples from various locations in the Thrace region of Turkey. The activity concentrations range from 12.82 to 101.75 Bq kg?1 d.w. (dry weight) for 238U, from 5.16 to 73.34 Bq kg?1 d.w. for 232Th, from 185.54 to 5399 Bq kg?1 d.w. for 40K and from 11.42 to 90.73 Bq kg?1 d.w. for 226Ra. In addition to naturally occurring radionuclides, 137Cs activity concentration is determined between 3.05 and 46.78 Bq kg?1 d.w. for soil samples. Determination of the radiological hazard is achieved through calculations of the external terrestrial gamma dose rate in air (nGy h?1) and annual effective dose rate (mSv year?1) and the results are compared with the similar works in different countries.  相似文献   

16.
The distribution of 137Cs and 239,240Pu in various ecosystems of the Kara Sea as well as speciation of these radionuclides has been studied to assess their potential mobility. In bottom sediment and seawater samples collected in Abrosimov, Tsivolky, Stepovoy, and Sedov Bays and on the coast of Novaya Zemlya, the content of anthropogenic radionuclides 137Cs and 239,240Pu does not exceed the values typical of the offshore zone in the Kara Sea (in sea water: 1.0–3.7 Bq/m3 for 137Cs and 50–90 mBq/m3 for 239,240Pu; in bottom sediments: 0.5–18.3 Bq/kg for 137Cs and 4.3–7.3 Bq/kg for 239,240Pu). The present monitoring study is important for the development of a long-term forecast for the dynamics of environmental contamination in the shallow bays of Novaya Zemlya.  相似文献   

17.
The aim of the present work was to determine the concentration of radionuclides in all kinds of tea available at the local Egyptian market. Radioactivity of the nuclides 238U, 226Ra, 210Pb, 228Th, 232Th, 226Ra, 137Cs and 40K were measured in tea by direct γ-ray spectrometry using HPGe detector and their mean values were 16.0±5.3, 3.1±0.7, 34.3±3.4, 3.4±1.2, 3.0±0.6, 3.1±0.8, 0.9±0.2 and 623±25 Bq·kg−1, respectively.  相似文献   

18.
The smear samples of the penetrator were analyzed for the determination of the uranium composition. The obtained relative composition (m/m) of uranium isotopes in all the smear samples is in the range of 99.76-99.78% for 238U, 0.000659-0.000696% for 234U, 0.213-0.234% for 235U, and 0.00274-0.00328% for 236U, showing characteristics of depleted uranium (DU). The uranium concentrations in Kosovo soil and water samples as well as biological samples were investigated. It was found that the uranium concentrations in the Kosovo soil samples are in the range of 11.3-2.26·105 Bq·kg-1 for 238U, 10.3-3.01·104 Bq·kg-1 for 234U, 0.60-3251 Bq·kg-1 for 235U, and £0.019-1309 Bq·kg-1 for 236U. The obtained activity ratios are in the range of 0.112-1.086 for 234U/238U, 0.0123-0.1144 for 235U/238U, and 0-0.0078 for 236U/238U, indicating the presence of DU in about 77% of the surface soil samples. At a specific site, the DU inventory in the surface soil is about 140 mg·cm-2, which is 1.68·106 times higher as the estimated mean DU dispersion rate in the region. The uranium concentrations in Kosovo lichen, mushroom, bark, etc., are in the range of 1.97-4.06·104 Bq·kg-1 for 238U, 0.48-5158 Bq·kg-1 for 234U, 0.032-617 Bq·kg-1 for 235U, and £0.019-235 Bq·kg-1 for 236U with mean activity ratios of 0.325±0.0223 for 234U/238U, of 0.0238±0.0122 for 235U/238U, and 0.0034±0.0028 for +U/238U, indicating the presence of DU in the entire sample. On the contrary, the uranium concentrations in Kosovo water samples are low, compared with the water samples collected in central Italy, indicating the presence of negligible amount of DU. The uranium isotopes in Kosovo waters do not constitute a risk of health at the present time. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

19.
Clam meats were obtained directly from the fishermen on the beaches in front of where the clams were collected at eight sites; seven along the northern coast of Venezuela and one on the northern coast of the island of Margarita (Venezuela). Marine sediments were also collected in the same corresponding areas as the clams. 137Cs was determined both in clam meats and the marine sediments by high resolution gamma-ray spectrometry employing a hyperpure germanium detector. About 5 kg portions of clam meats were washed and dried in the laboratory, before 500 cm3 volumes were transferred and weighed in the measuring containers. Similarly, 500 cm3 volumes of marine sediments that were dried and ground to pass a 85 μm sieve were transferred to the measuring containers. The samples were counted for 150,000 seconds of real time. The 137Cs activity of the clam meats ranged from <0.011 Bq·kg−1 (our detection limit) to 0.36 Bq·kg−1 (dried weigh). These values are all within the range of values considered for environmental fallout from the nuclear weapons tests. Finally, all the values for the corresponding marine sediments were below our detection limit of 0.1 Bq·kg−1 of 137Cs (dried weigh).  相似文献   

20.
Summary A reconnaissance study has been made on the distribution of 238U, 232 Th, 40K, 137Cs and geochemical features in soil and sediment samples at various locations in the coast of Persian Gulf. Activity concentration levels due to radionuclides were measured in 50 samples of soils and sediments collected from the coast of Hormozgan. From the measured spectra, activity concentrations were determined for 40K (range from 140 to 1172 Bq . kg-1), 137Cs (from 0 to 15 Bq . kg-1), 238 U (from 29 to 385 Bq . kg-1) and 2321 Th (from 9 to 156 Bq . kg-1) with the lowest limit of detection (LLD) of 68, 3.2, 4.3 and 4.3 Bq . kg-1, respectively. The dose rate from ambient air at the soil ranges was between 23 to 177 nGy . h-1 with an average of 60±7.86 nGy . h-1.  相似文献   

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