共查询到20条相似文献,搜索用时 15 毫秒
1.
M. N. Mori H. Oikawa M. H. O. Sampa C. L. Duarte 《Journal of Radioanalytical and Nuclear Chemistry》2006,269(1):99-102
Summary A survey was carried out to determine radioactivity concentrations and associated dose rates from the naturally occurring
nuclides 232 Th, 238U and 40K in various surface soil formations of Alhkraje city. Samples were collected from different areas of the study, sieved through
a fine mesh, sealed in 0.5-liter plastic Marinelli beaker, and measured in the laboratory for 24 hours each. From the measured
g-ray spectra, radioactivity concentrations were determined for 232 Th ranging from 5.32±2.59 to 16.40±2.04 Bq . kg-1, 238U (2.87±0.18 to 18.83±0.81 Bq . kg-1), 40K (211.33±55.04 to 378.97±36.46 Bq . kg-1) and 137Cs (0 to 3.19±1.02 Bq . kg-1). Absorbed dose rates in air doors were calculated to be in the range of 15.29±2.65 to 30.00±3.24 nGy . h-1, the corresponding effective dose rates per person outdoors were estimated to be between 21.00±0.95 to 36.83±2.11 mSν. y-1, assuming a 20% occupancy factor. 相似文献
2.
H. A. Ergül S. Topcuo?lu E. Ölmez Ç. K?rbaşo?lu 《Journal of Radioanalytical and Nuclear Chemistry》2006,268(1):133-136
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
3.
M. A. Misdaq H. Ouabi H. Elamyn 《Journal of Radioanalytical and Nuclear Chemistry》2006,270(3):543-553
Summary The 238U and 232 Th concentrations were measured in various potable water samples collected from various cities in Morocco using CR-39 and
LR-115 type II solid state nuclear track detectors (SSNTDs). The measured 238U and 232 Th concentrations ranged from 0.37±0.02 to 13.60±0.97 mBq . l-1 and 0.33±0.02 to 7.10±0.49 mBq . l-1, respectively. Alpha-activities due to annual 238U and 232 Th intakes were assessed in various compartments of the human body of adult members of the Moroccan population using ICRP
biokinetic models. The equivalent doses due to annual intakes of 238U and 232 Th were evaluated. The influence of the target tissue mass and the activities of 238U and 232 Th on the annual committed equivalent doses in the compartments of the human body was investigated. 相似文献
4.
Mark C. Okeji Kenneth K. Agwu Felicitas U. Idigo 《Radiation Physics and Chemistry》2012,81(12):1823-1826
Natural radioactivity in soil and vegetable samples in cultivated land in the vicinity of an active phosphate fertilizer plant in Kaduna, Nigeria was carried out to assess the potential radiological impact of the plant on its immediate environment. The activity counting was carried out using sodium iodide gamma spectrometry. The annual committed effective dose for two vegetables in the farmlands due to uranium (238U) and thorium (232Th) was assessed. The mean activity concentration of radionuclides in the soil samples ranges from 20.5±7.3 to 31.6±4.1 Bq kg?1 for 226Ra, 19.6±1.6 to 53.2±3.7 Bq kg?1 for 232Th and 203.9±6.3 to 253.6±9.5 Bq kg?1 for 40K. The annual intake of 238U and 232Th from consumption of okra were 1.9 Bq kg?1 and 5.22 Bq kg?1 and for tomatoes 2.66 Bq kg?1 and 5.1 Bq kg?1 respectively. The committed effective doses from consumption of okra and tomatoes were 0.1 μSv y?1 and 0.12 μSv y?1 respectively. 相似文献
5.
M. Flues I. M. C. Camargo P. S. C. Silva B. P. Mazzilli 《Journal of Radioanalytical and Nuclear Chemistry》2006,270(3):597-602
Summary The Figueira coal-fired power plant (CFPP) is among the Brazilian CFPP which presents higher uranium concentration. Gamma-ray
spectrometry was used to determine 238U, 226Ra, 210Pb, 232 Th and 40K contents in pulverized coal, furnace bottom ash and fly ash samples. The natural radionuclide concentrations in pulverized
coal ranged from 813 to 2609 Bq . kg-1 for U series and from 22 to 40 Bq . kg-1 for 232 Th. The fly ash fraction gave concentrations ranging from 1442 to 14641 Bq . kg-1, for uranium series. The same enrichment factor was observed for 238U, 226Ra and 232 Th. Only 210Pb and stable Pb presented a high enrichment factor for the last stage filter fly ash. The concentration of the uranium series
found in the ashes is close to the limit adopted by the Brazilian guideline (CNEN-NN-4.01).22 Therefore, it is advisable to evaluate the environmental impact of the installation. 相似文献
6.
I.A. Alnour H. Wagiran N. Ibrahim Z. Laili M. Omar S. Hamzah Bello.Y. Idi 《Radiation Physics and Chemistry》2012,81(12):1842-1847
This study was conducted to determine the concentration of natural radionuclides in the granite rocks of selected quarry sites in Johor state, Malaysia and their possible radiological effects. The activity concentrations of 238U, 232Th and 40K in the areas of study indicated varying values of 238U, 232Th and 40K. The highest values of 238U and 232Th concentrations (67±1 and 85±2 Bq kg?1, respectively) were observed at Kamad Quarry (IJM), whereas the highest value of 40K concentration (722±18 Bq kg?1) was detected in Kim Seng Quarry, while the values of activity concentration are lower in Hanson Quarry Products (Kulai) (25±0.5 for 238U, 24±0.5 for 232Th and 429±11 for 40K). Overall, 40K has the highest concentration in the granite rocks of the quarry sites, followed by 232Th and the least for 238U. The radium equivalent activity concentration was found in the range between 94 and 239 Bq kg?1, the absorbed dose rate was found to be in the range between 47 and 112 nGy h?1, and effective dose ranged from 58 to 137 μSv h?1. Moreover, the internal and external hazard index values were given in results lower than unity. 相似文献
7.
M. R. Abdi H. Faghihian M. Mostajaboddavati A. Hasanzadeh M. Kamali 《Journal of Radioanalytical and Nuclear Chemistry》2006,270(2):319-324
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
8.
The specific activity, hazard index, and the annual effective dose of the terrestrial naturally occurring radionuclides (238U, 232Th, and 40K) were determined in soil samples obtained from 20 sites of phosphate hills in the Russaifa region using an HPGe-detector of 50% relative efficiency. The resolution is 2 keV for the 1.33 MeV 60Co. The soil activity ranged from 5.3 to 1201.1 Bq kg?1 for 238U, 2.2 to 31.2 Bq kg?1 for 232Th, and 19.4 to 288.4 Bq kg?1 for 40K. Annual effective dose was found in the range 0.03–0.69 mSv. The external hazard index ranged from 0.15 to 3.29 Bq kg?1, while the global value given in UNSCEAR, 2000 publications is 1 Bq kg?1. The average values of the radium equivalent activities were determined for all sites and they were found to be approximately 319 Bq kg?1. This value is below the limit of 370 Bq kg?1 recommended by . The average value of the radium equivalent activities for certain locations (sample numbers: 2, 3, 4, 9, 10, and 14) is above the same limit. 相似文献
9.
S. Selvasekarapandian N. M. Manikandan R. Sivakumar V. Meenakshinundaram V.M. Raghunath 《Journal of Radioanalytical and Nuclear Chemistry》2002,252(2):429-435
The systematic study of background radiation and the distribution of radionuclides in the environment of Nilgiris biosphere in South India, have been carried out with an objective of establishing reliable baseline data on the background radiation level of the region. Soil samples have been collected at various places of Kotagiri taluk in Nilgiris biosphere and are analyzed for radioactivity measurements of primordial radionuclides by 3"×3" NaI(TI) gamma-ray spectrometer. It is observed that the average activity of 232Th series, 238U series and 40K in soil samples is found to be 102 Bq.kg–1, 41 Bq.kg–1 and 229 Bq.kg–1, respectively which contributes to a total gamma-dose of 86 nGy.h–1. Results of this systematic investigation establish the existence of wide range of variation in 232Th series, 238U series and 40K activities, which may be attributable to the existence of wide variety of lithological compounds in the zone under study. The ambient gamma-radiation dose measured is found to vary from 91 to 193 nGy.h–1 with a mean of 142.8 nGy.h–1. The measured ambient gamma-dose is more than 50% of the dose calculated from soil activities, which is due to the higher cosmic ray contribution to the total dose in the environment. The data is compared with different places around the world and the results are discussed in this paper 相似文献
10.
D. Amrani 《Journal of Radioanalytical and Nuclear Chemistry》2002,252(3):597-600
The activity concentrations of some radionuclides in Algerian bottled mineral waters were determined using CR-39 nuclear track detectors for 222Rn, and a high resolution gamma-ray spectrometry for 226Ra, 232Th and 40K. The mean specific activities of 222Rn , 226Ra, 231Th and 40K in the drinking mineral waters were 7±4 Bq.l-1, 26±11 mBq.l-1, 30±13 mBq.l-1 and 1±0.5 Bq.l-1, respectively. These values are comparable with concentrations reported for other countries. The effective doses due to intake of these radionuclides as a consequence of direct consumption of drinking mineral waters have been determined. The estimated effective doses were 56.8 mSv.y-1 for 222Rn, 3.94 mSv.y-1 for 226Ra, 4.45 mSv.y-1 for 232Th and 3.33 mSv.y-1 for 40K. Contribution of these radionuclides to the effective dose due to ingestion and inhalation of all terrestrial radionuclides is estimated to be only 0.012%. 相似文献
11.
M. Yukawa Y. Watanabe Y. Nishimura Y. Guo Z. Yongru H. Lu W. Zhang L. Wei Z. Tao 《Fresenius' Journal of Analytical Chemistry》1999,363(8):760-766
This study was carried out for the determination of 238U and 232Th concentrations in soil and various foods obtained in high natural radiation areas in China for estimating the internal
radiation doses caused by these radionuclides. Knowledge of the daily dietary intakes of the nuclides through foods is essential
to evaluate the internal radiation dose. Several analytical methods were evaluated for their applicability and quality assurance.
The accuracy and precision of ICP-MS is considerably better for determining trace elements like U and Th in fine powder samples.
The estimated annual effective dose is 0.302 μ Sv/y for 238U and 1.86 μ Sv/y for 232Th in the high natural radiation area, and 0.0101 μ Sv/y for 238U and 0.177 μ Sv/y for 232Th in the control area.
Received: 25 September 1998 / Revised: 3 December 1998 / Accepted: 8 December 1998 相似文献
12.
Khalid Khan P. Akhter S. D. Orfi G. M. Malik M. Tufail 《Journal of Radioanalytical and Nuclear Chemistry》2003,256(2):289-292
Natural radioactivity in the aquatic media has been determined by collecting samples of river, stream and drinking water from the northwestern areas of Pakistan. The concentrations of 40K, 226Ra and 232Th have been measured using a low background gamma-spectrometer and a 10 cm3 planar intrinsic high purity germanium detector. The annual ingestion of these radionuclides, using local consumption rates (average over the whole population) of 0.9 l.d-1, were estimated to be 49.2, 6.2 and 1.1 Bq.y-1 for 40K, 226Ra and 232Th, respectively. A comparison of the annual intakes of these radionuclides, using annual consumption rates of NCRP, ICRP and FBSP shows that the contribution from natural radionuclides to annual intake is slightly greater for NCRP than for ICRP and FBSP consumption rates. However, the estimated values and weighted means of these radionuclides compare well with the world average. The annual effective dose equivalent from drinking water was found to be 3.6.10-6 mSv.y-1 (226Ra), 3.2.10-12 mSv.y-1 (232Th) and 2.1.10-6 mSv.y-1 (40K). These values are lower than those given by NCRP. 相似文献
13.
M. Yukawa Y. Watanabe Y. Nishimura Y. Guo Z. Yongru H. Lu W. Zhang L. Wei Z. Tao 《Analytical and bioanalytical chemistry》1999,363(8):760-766
This study was carried out for the determination of 238U and 232Th concentrations in soil and various foods obtained in high natural radiation areas in China for estimating the internal radiation doses caused by these radionuclides. Knowledge of the daily dietary intakes of the nuclides through foods is essential to evaluate the internal radiation dose. Several analytical methods were evaluated for their applicability and quality assurance. The accuracy and precision of ICP-MS is considerably better for determining trace elements like U and Th in fine powder samples. The estimated annual effective dose is 0.302 μ Sv/y for 238U and 1.86 μ Sv/y for 232Th in the high natural radiation area, and 0.0101 μ Sv/y for 238U and 0.177 μ Sv/y for 232Th in the control area. 相似文献
14.
M. Aslam S. D. Orfi K. Khan A. Jabbar 《Journal of Radioanalytical and Nuclear Chemistry》2002,253(3):483-487
Natural radioactivity in various types of marbles available in Rawalpindi/Islamabad industrial area have been assessed using HP(Ge) gamma-ray spectrometer. The concentration of 40K, 226Ra and 232Th ranges from 6.15 to 159.65 Bq.kg-1, 1.45 to 29.34 Bq.kg-1 and 1.16 to 6.28 Bq.kg-1, respectively. The radium equivalent activity lies between 5.56 to 33.42 Bq.kg-1. The average external and internal indices have been found to be 0.03 and 0.05, respectively. The average absorbed dose rate at 1 m was found to be 6.53 nGy.h-1. The estimated annual effective dose rate for whole body was found to be 0.04 mSv.y-1. These values are smaller than those predicted by UNSCEAR for normal background areas. The marbles analyzed pose less health hazard as compared to Pakistani baked bricks and other construction materials. 相似文献
15.
R. Ravisankar A. Chandrasekaran P. Vijayagopal B. Venkatraman G. Senthilkumar P. Eswaran A. Rajalakshmi 《Radiation Physics and Chemistry》2012,81(12):1789-1795
The natural radioactivity of soils at Yelagiri hills has been studied in this paper. The radioactivities of 25 samples have been measured with a NaI(Tl) detector. The radioactivity concentrations of 238U, 232Th and 40K ranged from ≤2.17 to 53.23, 13.54 to 89.89 and from 625.09 to 2207.3 Bq kg?1, respectively. The measured activity concentrations for these radionuclides were compared with world average activity of soil. The average activity concentration of 232Th in the present study is 1.19 times higher than world median value while the activity of 238U and 40K is found to be lower. In order to evaluate the radiological hazard of the natural radioactivity, the radium equivalent activity Raeq, the absorbed dose rate DR, the annual effective dose rate and the external hazard index (Hex) have been calculated and compared with the internationally approved values. The study provides background radioactivity concentrations in Yelagiri hills. 相似文献
16.
J. A. S. Júnior J. J. R. F. Cardoso C. M. Silva S. V. Silveira R. S. Amaral 《Journal of Radioanalytical and Nuclear Chemistry》2006,269(2):451-455
Summary Seventy nine samples, including soil and rock, were collected from the agrestic region of the State of Pernambuco, Brazil.
The activity concentrations of 238U and 226Ra in the samples were determined by gamma-spectrometry using an HPGe detector. The concentrations of 238U were 22 Bq . kg-1 to 22 kBq . kg-1. The concentrations of 226Ra were 14 Bq . kg-1 to 17 kBq . kg-1. The 238U/226Ra ratios in the soil were 0.7 to 3.4 (arithmetic mean 1.7). The radiometric data were evaluated to explain 238U and 226Ra migration in the soil and the possible consequences to the environment. 相似文献
17.
C. Papastefanou S. Stoulos M. Manolopoulou 《Journal of Radioanalytical and Nuclear Chemistry》2005,266(3):367-372
Summary Radiation exposure of the population can be increased appreciably by the use of building materials containing above-normal
levels of naturally occurring radionuclides of terrestrial origin, as high as 1600 Bq. kg-1for 40K in granites, 700 Bq. kg-1for 226Ra in phosphogypsum and 360 Bq. kg-1for 232Th in granites. In a 25-year survey including more than two hundreds of different materials were investigated. Of the materials
normally used in the building industry, i.e., red clay bricks, cement of Portland Types I and II, concretes, gravels and sand,
contain regular levels of the primordial radionuclides. The adsorbed dose rate in indoor air, in general, does not exceed
the dose criterion of 80 nGy. h-1or 0.3 mSv. y-1for the effective dose. Granites and phosphogypsum are the highly radioactive materials for which the absorbed dose rate in
indoor air becomes up to five times higher than the dose criterion. It is recommended to avoid the use of those materials
without radioactivity control. 相似文献
18.
A. K. Patra J. Sudhakar P. M. Ravi J. P. James A. G. Hegde M. L. Joshi 《Journal of Radioanalytical and Nuclear Chemistry》2006,270(2):307-312
Summary The activity and absorbed dose rate of the naturally occurring radionuclides, viz. 238U, 232 Th and 40K were determined in soil and rock samples collected around Kaiga site. The mean activity levels (Kaiga soil) of naturally
occurring 232 Th are comparable with that in worldwide soil, while concentrations of 238U and 40K are lower than those in worldwide soil. The absorbed dose rate in outdoor air ranged 20-58 nGy . h-1 with a mean of 33.3 nGy . h-1, which is below the world average of 60 nGy . h-1. The total effective dose rate in outdoor air for soils ranged 25.6-74.4 mSv . y-1 with a mean of 43.0 mSv . y-1. The estimated dose rate at Kaiga is comparable with that estimated at Kakrapar and Rawatbhata and much less than that estimated
at coastal sites of India. 相似文献
19.
Natural radioactivity measurements and assessment of radiological hazards in soil and sand samples obtained from Penang, Malaysia were carried out using the Exploranium GR-135 Plus “Identifier” Radioisotope Identification Device and high-resolution High Purity Germanium (HPGe) detector system. The activity concentrations of 238U, 226Ra, 232Th, and 40K were found to be 184±11, 396±22, 165±14, and 835±28 Bq kg?1 respectively, and the external gamma dose rate is 315±44 nGy h?1 for soil samples. For sand samples, the activity concentrations of 238U, 226Ra, 232Th and 40K were 31±8, 62±16, 36±6, and 369±17 Bq kg?1, respectively, and the external gamma dose rate is 66±12 nGy h?1. To assess the radiological hazard of radioactivity present in the samples, the radium equivalent activity, annual effective dose, annual gonadal dose equivalent, external hazard, and internal indices were calculated.The Raeq values of soil samples were higher than the limit of 370 Bq kg?1, which is equivalent to a gamma dose of 1.5 mSv yr?1, whereas the Raeq for sand samples was lower than 370 Bq kg?1. The calculated concentrations by HPGe spectroscopy were compared with the measured concentrations detected by a GR-135 spectrometer. The calculated and measured gamma dose rates had an ideal correlation coefficient R of 0.72. The gamma dose rates in Penang increased with the average annual age-standardized rates (ASR) for all cancers between 1994 and 2010. The effects of the pH value of soil and sand samples on natural radionuclides concentrations were investigated. The high concentration of 226Ra/238U ratio disequilibrium (226Ra/238U of 1.76–2.33) was observed in the sampling sites. Moreover, a portable continuous radon monitor (SNC, model 1029, Sun Nuclear Corporation) was used to measure the radon concentration of the soil surface. The radon concentrations were found to vary from 7 to 50 Bq m?3. A positive correlation was observed between the radon and radium concentrations in samples measured by the SNC continuous radon monitor and HPGe detector. 相似文献
20.
Mohammad A. Hannan Nam Nguyen Manuel Rivas 《Journal of Radioanalytical and Nuclear Chemistry》2013,295(1):729-736
The activity concentration of radionuclides in 238U, 232Th, and 40K were determined in Mission (Texas) surface soils through gamma-ray spectrometry measurements using hyper pure germanium detector. Activity concentrations of 238U, 232Th, and 40K were 13–32 Bq kg?1 (mean value: 23 Bq kg?1), 17–47 Bq kg?1 (mean value: 31 Bq kg?1), and 100–460 Bq kg?1 (mean value: 300 Bq kg?1) respectively. The absorbed gamma dose rate in air from these soils were found in the range of 23 to 56 nGy h?1 with an average value of 42 nGy h?1. The contribution to the absorbed gamma dose rate in air was observed as 26 % from 238U, 45 % from 232Th, and 29 % from 40K. The outdoor annual effective dose equivalent varied between 28 and 69 μSv y?1 with the mean value of 52 μSv y?1.The evaluated data were compared with the data from different countries and also with the world mean value. 相似文献