scholarly journals Evaluation of the natural radioactivity level of Nigerian tar sand deposits, eastern Dahomey basin, southwestern Nigeria

2016 ◽  
Vol 31 (1) ◽  
pp. 79-88 ◽  
Author(s):  
Adewale Akinmosin ◽  
Michael Oladunjoye ◽  
Fabian Essien
Keyword(s):  
Effective Dose ◽  
Annual Effective Dose ◽  
Natural Radionuclides ◽  
Hazard Index ◽  
Dose Equivalent ◽  
Southwestern Nigeria ◽  
External Hazard Index ◽  
Radium Equivalent ◽  
Dahomey Basin ◽  
Specific Activities

The specific activities of natural radionuclides in twenty seven samples collected from the eastern Dahomey basin in southwestern Nigeria were evaluated. Experimental results were obtained by using a 3" x 3" sodium iodide NaI(Tl) detector. A major trace element assessment of the samples was made by Inductively Coupled Plasma Mass Spectrometry techniques. Gamma ray radioactive standard sources, 137Cs and 60Co, were used to calibrate the measurement system and the International Atomic Energy Agency SOIL-375 radioactive standard source was also used to analyze and compute the specific activities of desired natural radionuclides. Three radioelements, viz. 238U, 232Th and 40K, were identified in the samples with the following specific activities of 238U ranging from 9.88 ? 4.70 Bq/kg to 69.15 ? 12.37 Bq/kg with an average of 26.50 ? 7.18 Bq/kg; 232Th from 12.78 ? 5.16 Bq/kg to 36.86 ? 13.35 Bq/kg with an average of 22.77 ? 4.28 Bq/kg; 40K ranging from 189.82 ? 79.51 Bq/kg to 518.77 ? ? 119.54 Bq/kg with an average of 297.69 ? 16.21 Bq/kg. The result was compared with the world mean values of 35, 30 and 400 Bq/kg, respectively, specified by the United Nations Scientific Committee on the Effects of Atomic Radiation. The mean result obtained for the radium equivalent, total absorbed dose rate, external hazard index, internal hazard index, and the annual effective dose equivalent, were 79.90 Bq/kg, 38.50 ?Sv/h, 0.22 Bq/kg, 0.29 Bq/kg, and 47.22 ?Sv, respectively. With respect to radiological risk to human health, the absorbed gamma dose rate in air was estimated to be in the range of 21.7 ? 0.4 to 155.7 ? 2.2 ?Sv/h; the outdoor annual effective dose equivalent was evaluated to vary from 26.6 ? 0.4 to 190.9 ? ? 2.7 ?Sv with the arithmetic mean value of 79.06 ? 33.23 ?Sv and compared to the world-wide effective dose of 70 ?Sv. Also, the values of the radium equivalent and the external hazard index for all samples in the study area were found to be lower than the accepted safety limit value of 370 Bq/kg and equally below the limit of unity, respectively. The results indicate that, at present, the radiation hazard from radionuclides in all samples analyzed is within permissible limits.

Natural Radioactivity of Topsoil in Two Granite Areas of Guangzhou, South China

2014 ◽  
Vol 955-959 ◽  
pp. 3691-3695
Author(s):  
Gang Song ◽  
Min Xing Lu ◽  
Qiu Ping Zhu ◽  
Di Yun Chen ◽  
Yong Heng Chen
Keyword(s):  
Effective Dose ◽  
Annual Effective Dose ◽  
Natural Radionuclides ◽  
Hazard Index ◽  
Natural Radionuclide ◽  
Soil Samples ◽  
Absorbed Dose Rate ◽  
Radium Equivalent Activity ◽  
External Hazard Index ◽  
Radium Equivalent

The natural radionuclide (238U, 226Ra, 232Th and 40K) concentrations in 152 soil samples were determined from two major granite areas in Guangzhou, using high resolution γ-ray spectroscopic system based on the characteristic spectral peaks. The mean activity values for 238U, 226Ra, 232Th and 40K were found to be 156.6±98.8, 160.9±96.5, 184.8±101.5 and 832.5±493.1 Bq kg–1 dry mass, respectively. The absorbed dose rate (D) calculated from activity concentration of 226Ra, 232Th and 40K ranged from 53.2 to 497.1 nGy h–1 with a mean of 220.7 nGy h–1. The Radium equivalent activity (Raeq), the outdoor annual effective dose and the external hazard index (Ir), which resulted from the natural radionuclides in soil, were also calculated and found to vary from 119.7 to 1117.2 Bq kg–1, from 0.07 to 0.61 mSv and from 0.33 to 3.07, respectively. The radium equivalent activities and the external hazard index in all the soil samples were same as 64.5% higher than the limit of 370 Bq kg–1 and 1.0, respectively. The outdoor annual effective dose was higher than the worldwide mean value of 0.07 mSv.

scholarly journals Determination of natural radioactivity, 222Rn and 220Rn exhalation rates and radiation hazards of fly ash and fly ash brick used in Baotou, China

2016 ◽  
Vol 31 (3) ◽  
pp. 282-290 ◽  
Author(s):  
Yuxin Li ◽  
Xinwei Lu ◽  
Xiaolan Zhang
Keyword(s):  
Fly Ash ◽  
Effective Dose ◽  
Natural Radioactivity ◽  
Annual Effective Dose ◽  
Hazard Index ◽  
Radium Equivalent Activity ◽  
Radiation Hazards ◽  
External Hazard Index ◽  
Radium Equivalent ◽  
Local Residents

Natural radioactivity levels, 222Rn and 220Rn exhalation rates and radiation hazards of fly ash and fly ash brick used in Baotou, China were determined. The activity concentrations of 226Ra, 232Th, and 40K in fly ash samples ranged from 38.81 to 93.73, 40.34 to 135.17, and 66.92 to 290.86 Bq/kg with an average of 76.52, 109.95, and 170.72 Bq/kg, respectively; while in fly ash brick samples, these radionuclides ranged from 42.43 to 71.60, 76.65 to 208.37, and 94.32 to 489.42 Bq/kg with an average of 53.83, 101.93, and 266.48 Bq/kg, respectively. The exhalation rates of 222Rn and 220Rn in all determined samples were in the range of 1.13-20.50 and 15.60-113.00 mBq/m2s, respectively. The calculated results of the radium equivalent activity, external hazard index, internal hazard index, indoor annual effective dose and outdoor annual effective dose indicated that fly ashes and fly ash bricks collected from some brick factories of Baotou would pose excessive radiation risks to inhabitants and that they are not suitable for use in building construction. The natural radioactivity level of fly ash and fly ash brick needs to be constantly monitored considering the radiation safety of the local residents.

Study of the natural radioactivity of selected samples of the soil of Al-Nada district in Najaf

2018 ◽  
Vol 31 (3) ◽  
pp. 43
Author(s):  
Heiyam Najy Hady ◽  
Shahad Fadel Kadim
Keyword(s):  
Effective Dose ◽  
Gamma Ray ◽  
Background Radiation ◽  
Annual Effective Dose ◽  
Natural Radionuclides ◽  
Hazard Index ◽  
Absorbed Dose ◽  
Gamma Ray Spectrometer ◽  
External Hazard Index ◽  
Reporting Data

   This study reported activity concentration of 238 U, 232 Th, 40 K in 50 soil samples AL-Nada district - Najaf Governorate - Iraq Measurement using gamma ray spectrometer NaI (TI) (3x3). The activity concentrations of natural radionuclides are found to range from (31.319  Bq.Kg-1 to (1.1583 ± 0.0821) Bq.Kg-1with average (11.851 0.281) Bq.Kg-1 of uranium 238U.  From (1.117±0.048)  Bq.Kg-1 to  (23.948 ) Bq.Kg-1  with an  average of  (6.283 0.148 ( Bq.Kg-1 for thorium 232Th,.from(13.592±0.282) Bq.Kg-1 to (705.834 6.179) Bq.Kg-1 and average (265.494 1.445) Bq.Kg-1 potassium40K , equivalent radium  from (12.489 0.328) Bq.Kg-1 to (84.199 1.911) Bq.Kg-1 and average (40.078 0.564) Bq.Kg-1 , internal  hazard index from (0.039) Bq.Kg-1to( 0.256) Bq.Kg-1 and average( 0.139) Bq.Kg-1,external hazard index ranged from( 0.033) Bq.Kg-1 to (0.227) Bq.Kg-1 and average( 0.108) Bq.Kg-1 values  either of absorbed dose in air from (5.728 0.150) nGy/h to (42.667 0.901) nGy/h and average(19.914 0.264) nGy/h  , internal annual effective dose from (0.028 0.0005) mSv/y to (0.209 0.0044) mSv/y and average (0.097 0.0013) mSv/y, external annual effective dose from (0.0070 0.0001) mSv/y to (0.0523 0.001) mSv/y  and average (0.0244 0.0003) mSv/y The results were found to be comparable or lower than similar global reporting data. According to this, research soil The area can be considered to have a normal level of natural background radiation  

scholarly journals A review: Natural and artificial radionuclides and radiation hazard parameters in the soil of mountain regions in Serbia

2020 ◽  
Vol 65 (1) ◽  
pp. 1-18
Author(s):  
Branislava Mitrovic ◽  
Dragana Todorovic ◽  
Jelena Ajtic ◽  
Borjana Vranjes
Keyword(s):  
Natural Radionuclides ◽  
Hazard Index ◽  
Absorbed Dose ◽  
Radiation Hazard ◽  
Dose Equivalent ◽  
Absorbed Dose Rate ◽  
Radium Equivalent Activity ◽  
Lifetime Cancer Risk ◽  
External Hazard Index ◽  
Hazard Parameters

This review paper discusses the content of natural (40K, 238U, 226Ra, and 232Th) and artificial (137Cs) radionuclides in the soil of the mountains of Maljen, Tara and Kopaonik in the Republic of Serbia over 2002-2015. In addition, the paper gives radiation hazard parameters, i.e., radium equivalent activity, absorbed dose rate, annual effective dose equivalent, external hazard index, annual gonadal dose equivalent, and excess lifetime cancer risk outdoors that we calculated from the obtained content of the natural radionuclides in the soil samples. We compared the parameters to previously published results for different parts of the country and looked into the radioecological status of the investigated areas.

scholarly journals Specific Activities of Natural Radionuclides and Annual Effective Dose Due to the Intake of Some Types of Children Powdered Milk Available in Baghdad Markets

2017 ◽  
Vol 14 (3) ◽  
pp. 619-624
Author(s):  
Baghdad Science Journal
Keyword(s):  
Effective Dose ◽  
Sodium Iodide ◽  
Specific Activity ◽  
Annual Effective Dose ◽  
Natural Radionuclides ◽  
Mean Value ◽  
Powdered Milk ◽  
Effective Doses ◽  
The Mean ◽  
Specific Activities

In this research the specific activity of natural radionuclides 226Ra, 232Th and 40K were determined by sodium iodide enhanced by thallium NaI(TI) detector and assessed the annual effective dose in Dielac 1 and 2 and Nactalia 1 and 2 for children of less than 1 year which are available in Baghdad markets. The specific activity of 40K has the greater value in all the types which is in the range of allowed levels globally that suggested by UNSCEAR. The mean value of annual effective doses were 2.92, 4.005 and 1.6325 mSv/y for 226Ra, 232Th and 40K respectively.

Assessment of Natural Radionuclides in Local and Imported Cements in Erbil Governorate, Kurdistan Region- Iraq

2020 ◽  
Vol 13 (1) ◽  
pp. 73-77
Keyword(s):  
Sodium Iodide ◽  
Specific Activity ◽  
Annual Effective Dose ◽  
Natural Radionuclides ◽  
Absorbed Dose ◽  
Dose Equivalent ◽  
Hazard Indices ◽  
Spectrometry Analysis ◽  
Radium Equivalent ◽  
Radiological Hazard Indices

A total of 10 cement samples were collected from the manufactures and markets. Spectrometry analysis of Sodium Iodide NaI (Tl) detector was used for measuring the samples' specific activity. The obtained specific activities of (226Ra, 232Th and40 K) were (35, 30 and 400) Bq/kg, respectively, which are below the critical values suggested by UNSCEAR2000. The radiological hazard indices of radium equivalent activities (Raeq), the indoor absorbed dose , the internal annual effective dose equivalent (Ein) and the internal index (Hin) were calculated. All of the obtained values were below the world wide recommendation values. Fortunately, from the analyzed results, it was concluded that the local and imported cements in Erbil governorate will make no risk when used in building constructions.

scholarly journals Environmental radioactivity in southern Serbia at locations where depleted uranium was used

2014 ◽  
Vol 65 (2) ◽  
pp. 189-197 ◽  
Author(s):  
Nataša B. Sarap ◽  
Marija M. Janković ◽  
Dragana J. Todorović ◽  
Jelena D. Nikolić ◽  
Milojko S. Kovačević
Keyword(s):  
Natural Radionuclides ◽  
Hazard Index ◽  
Depleted Uranium ◽  
Radium Equivalent Activity ◽  
Gross Alpha ◽  
External Hazard Index ◽  
Radionuclide Content ◽  
Radium Equivalent ◽  
Radioactivity Monitoring

AbstractIn the 1999 bombing of the Federal Republic of Yugoslavia, NATO forces used ammunition containing depleted uranium. The cleaning of depleted uranium that followed was performed in southern Serbia by the Vinča Institute of Nuclear Sciences between 2002 and 2007 at the locations of Pljačkovica, Borovac, Bratoselce, and Reljan. This paper presents detailed results of radioactivity monitoring four years after cleaning (2011), which included the determination of gamma emitters in soil, water, and plant samples, as well as gross alpha and beta activities in water samples. The gamma spectrometry results showed the presence of natural radionuclides 226Ra, 232Th, 40K, 235U, 238U, and the produced radionuclide 137Cs (from the Chernobyl accident). In order to evaluate the radiological hazard from soil, the radium equivalent activity, the gamma dose rate, the external hazard index, and the annual effective dose were calculated. Considering that a significant number of people inhabit the studied locations, the periodical monitoring of radionuclide content is vital.

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