Natural radioactivity measurements and external dose estimation by car-borne survey in Douala city, Cameroon

2018 ◽  
Vol 53 (4) ◽  
pp. 255-263 ◽  
Author(s):  
S.D. Takoukam Soh ◽  
Saïdou ◽  
M. Hosoda ◽  
J.E. Ndjana Nkoulou II ◽  
N. Akata ◽  
...  
Keyword(s):  
Dose Rate ◽  
Absorbed Dose ◽  
Distribution Map ◽  
Heterogeneous Distribution ◽  
World Average ◽  
Dose Rates ◽  
Average Value ◽  
Activity Concentrations ◽  
The World

A car-borne survey was carried out in Douala, the largest city in Cameroon to make a detailed distribution map of the absorbed dose rate in the city, to locate the high natural radiation areas useful later to carry out indoor radon, thoron, and thoron progeny measurements. Gamma-ray dose rates were measured using 3-in × 3-in NaI(Tl) detector. Activity concentrations of238U,232Th and40K in soil from Douala city were determined by two methods: the first, usingin situgamma spectrometry and the second, at the laboratory using a NaI(Tl) detector. A heterogeneous distribution of absorbed dose rates in air was observed on the dose rate distribution map, and varies from 29 to 86 nGy h−1with an average of 50 nGy h−1, lower than the world average value of 59 nGy h−1. The activity concentrations with NaI(Tl) detector varied from 18 to 47 Bq kg−1for238U, 21 to 54 Bq kg−1for232Th, and 10 to 410 Bq kg−1for40K with averages of 29, 38, and 202 Bq kg−1respectively, forin situmeasurements. They vary between 29–98 Bq kg−1for238U, 29–92 Bq kg−1for232Th, and 40 to 79 Bq kg−1for40K, with averages of 60, 57, and 56 Bq kg−1respectively for soil samples collected at Douala III subdivision. The highest value of the annual effective dose forin situmeasurements by car was observed at Ndogbong and was found to be 0.7 mSv y−1, higher than the world average value of 0.5 mSv y−1.

scholarly journals Distribution of Radionuclides in Surface Soil and Bottom Sediment in the District of Jessore, Bangladesh and Evaluation of Radiation Hazard

1970 ◽  
Vol 33 (1) ◽  
pp. 117-130 ◽  
Author(s):  
KA Kabir ◽  
SMA Islam ◽  
MM Rahman
Keyword(s):  
Dose Rate ◽  
Surface Soil ◽  
Absorbed Dose ◽  
Hazard Indices ◽  
Absorbed Dose Rate ◽  
Radium Equivalent Activity ◽  
World Average ◽  
Radium Equivalent ◽  
The World ◽  
Soil And Sediment

This paper presents the first reports on the natural and anthropogenic radionuclides in soil and sediment of Jessore, a south-western district of Bangladesh. Surface soil and freshwater sediment were collected from in and around some major water-bodies of this district. To assess the radiological hazard of the natural radioactivity, the radium equivalent activity, the absorbed dose rate, and the external and internal hazard indices were calculated. In the soil and sediment in general, the activity concentration of 232Th was found to be higher than that of  226Ra, while that of 40K markedly exceeds the values of both 226Ra and 232Th. The average activities of 226Ra and 232Th in this area were found to be higher than the world average. There was no activity due to fallout (137Cs) in this area. The radium equivalent activity and the absorbed dose rate due to the natural radionuclides were found to be respectively lower and higher than the world average. The external and internal hazard indices were found to be well below the hazard limit of unity. Our results compare fairly well with other published results.  Key words: Soil, Sediment, Natural lake, Radioactivity, Dose rate DOI: 10.3329/jbas.v33i1.2956 Journal of Bangladesh Academy of Sciences, Vol. 33, No. 1, 117-130, 2009

Natural Radioactivity Measurement in Soil Samples From The New Kufa University Location, Iraq

2013 ◽  
Vol 3 (2) ◽  
pp. 232-240 ◽  
Author(s):  
Heiyam Najy Majeed ◽  
Ali . K. Hasan
Keyword(s):  
Effective Dose ◽  
Dose Rate ◽  
Activity Concentration ◽  
Annual Effective Dose ◽  
Absorbed Dose ◽  
Soil Samples ◽  
Absorbed Dose Rate ◽  
World Average ◽  
Two Samples ◽  
The World

Al-Najaf Al-Ashraf city on of the most important cities in Iraqi country it was chosen as the cultural Islamic capital for 2012 by the Islamic world ,Kufa university will be played big role of liability, cultural and education efficacies, this city had been exposed to artillery bombard expand along different areas in 1991 and 2003 in our research we try to test the studying area to know The total absorbed dose rate and the most possible hazards for this reasons the study was done. The natural radiation of thirty two samples of soil which collected randomly in June 2012 from the new Kufa University location were measured using Na(Tl) detection. The mean values activity concentrations of 238U, 232Th and 40K was (25.73±11.23 , 3.72±0.81 and 165.16±9.39 ) Bq kg-1 respectively . The highest value of the Radium equivalent activity was (30.870) Bq.kg–1 in (S2) which mean that all the soil samples values lower than (370Bq kg-1) the world average . External and internal hazard and gamma activity concentration (representative level index) indexes were lower than unity for all samples . The average value of absorbed dose rate calculated from activity concentration of 238U , 232Th and 40K was (20.553) nGy h-1 this value coincident to recommended. Annual effective dose in (?Sv/y) varies from (36.912) (?Sv/y) in (S15) to (15.460) (?Sv/y) in (S8) , all the soil samples have the annual effective dose less than the world average 460 (?Sv/y). The results can be consider as base values for distribution of natural radionuclides in the region and will be used as references information to assess any changed in the radioactive background level due to geological processes.

scholarly journals Radioactivity of soil in Croatia II: 137Cs, 40K, and absorbed dose rate

2021 ◽  
Vol 72 (1) ◽  
pp. 15-22
Author(s):  
Marko Šoštarić ◽  
Branko Petrinec ◽  
Mak Avdić ◽  
Ljerka Petroci ◽  
Milica Kovačić ◽  
...  
Keyword(s):  
Dose Rate ◽  
Gamma Ray ◽  
Absorbed Dose ◽  
Gamma Ray Spectrometry ◽  
External Exposure ◽  
Vegetation Density ◽  
Absorbed Dose Rate ◽  
Dose Rates ◽  
Activity Concentrations ◽  
Uncultivated Soil

Abstract We took samples of uncultivated soil from the surface layer (0–10 cm) at 138 sites from all over Croatia and measured their radionuclide activity concentrations with high-resolution gamma-ray spectrometry. This second part of our report brings the results on 40K and 137Cs to complement those on the 232Th and 238U decay chains addressed in the first part. Together they give the most complete picture of radioactivity of Croatian soil so far. Activity concentrations of 40K were the highest in the Pannonian region, and there was an opposite trend for 137Cs. We found that the concentrations of 137Cs tended to increase with altitude, annual precipitation, and vegetation density. The concentration ratio of 137Cs and K in soil, which indicates the potential for 137Cs entering food chains via uptake by plants, was the lowest in agriculturally important areas in the east of the Pannonian region. In addition, we used the obtained results on activity concentrations to calculate the related absorbed dose rate as a measure of external exposure to ionising radiation from soil. The sum of the absorbed dose rates for naturally occurring radionuclides and 137Cs showed that external exposure was generally the highest in the Dinaric region and Istrian Peninsula.

scholarly journals Natural radioactivity and external dose assessment of surface soils in Bolikhamxay province, Laos

2017 ◽  
Vol 33 (4) ◽  
Author(s):  
Loat Bui Van
Keyword(s):  
Activity Concentration ◽  
Natural Radionuclides ◽  
Soil Samples ◽  
Dose Assessment ◽  
World Average ◽  
Average Value ◽  
Activity Concentrations ◽  
Radium Equivalent ◽  
The World ◽  
Average Activity

We have determined activity concentrations in 33 soil samples collected from Bolikhamxay Province, Laos. The activity concentrations of the natural radionuclides 226Ra,232Th and 40K in soil samples were measured by a gamma spectrometer with a HPGe detector. The average activity concentrations of the natural radionuclides 226Ra, 232Th and 40K are 43.8 ± 5.6, 57.0 ± 7.3 and 426.4 ± 23.1 Bq.kg-1, respectively. The average activity concentrations of 226Ra and 232Th in this work are higher than those of the world average values. Meanwhile, the  activity concentration of 40 K is almost the same of the world average value. The estimated average outdoor annual effective dose (E) and radium equivalent actitvity (Raeq) are 0.17 ± 0.02 mSv.yr-1 and 154.8 ± 16.1 Bq.kg-1, respectively.

HUMAN EXPOSURE TO BACKGROUND RADIATION IN ORTUM, KENYA

2019 ◽  
Vol 188 (1) ◽  
pp. 98-108
Author(s):  
F O Wanjala ◽  
N O Hashim ◽  
D Otwoma ◽  
C Nyambura ◽  
J Kebwaro ◽  
...  
Keyword(s):  
Dose Rate ◽  
Human Exposure ◽  
Activity Concentration ◽  
Background Radiation ◽  
Absorbed Dose ◽  
Threshold Values ◽  
Absorbed Dose Rate ◽  
The World ◽  
Average Activity ◽  
Terrestrial Radionuclides

Abstract The activity concentration of radionuclides 238U, 232Th and 40K in soil and the absorbed dose rate (ADRA) at 1 m above the ground in Ortum was determined. The activity concentration in soils ranged from 33 to 85, 20 to 67 and 148–1019 Bq kg–1, respectively with an average of 40 ± 1.43, 56 ± 1.46 and 425 ± 19.24 Bq kg–1, respectively. The activity concentration of 232Th and 238U was found to reduce with increasing depth while that of 40K increased with increasing depth. The average activity concentration in soil was higher than the world average values. The average ADRA in air at 1 m above the ground was found to be 112 ± 29.6 nGy h–1. The soil and rocks in Ortum are recommended for use because the activity concentration of the terrestrial radionuclides is lower than the recommended threshold values.

Assessment of natural radioactivity levels and the associated radiological hazards in some building materials from Mayo-Kebbi region, Chad

2018 ◽  
Vol 53 (4) ◽  
pp. 265-278 ◽  
Author(s):  
S. Penabei ◽  
D. Bongue ◽  
P. Maleka ◽  
T. Dlamini ◽  
Saïdou ◽  
...  
Keyword(s):  
Dose Rate ◽  
Natural Radioactivity ◽  
Building Materials ◽  
Hazard Index ◽  
Absorbed Dose ◽  
Radiation Hazard ◽  
Absorbed Dose Rate ◽  
Activity Concentrations ◽  
Radiological Hazards ◽  
Radiation Hazard Index

In order to assess the levels of natural radioactivity and the associated radiological hazards in some building materials of the Mayo-Kebbi region (Chad), a total of nineteen samples were collected on the field. Using a high resolution γ-ray spectrometry system, the activity concentrations of radium (226Ra), thorium (232Th) and potassium (40K) in these samples have been determined. The measured average activity concentrations range from 0.56 ± 0.37 Bq kg−1 to 435 ± 7 Bq kg−1, 1.3 ± 0.6 Bq kg−1 to 50.6 ± 1.1 Bq kg−1 and 4.3 ± 2.0 Bq kg−1 to 840 ± 9 Bq kg−1, for 226Ra, 232Th and 40K, respectively. The highest 226Ra average activities is found in soil brick samples of Zabili. The highest mean value of 232Th and 40K concentrations are found in soil brick samples of Madajang. The activity concentration and the radium equivalent activity (Raeq) have been compared to other studies done elsewhere in the world. Their average values are lower than most of those of countries with which the comparison has been made. Were also evaluated, the external radiation hazard index, the internal radiation hazard index, the indoor air absorbed dose rate, the outdoor air absorbed dose rate, the activity utilization index, the annual effective dose, the annual gonadal dose equivalent, the representative level index, as well as, the excess lifetime cancer risk. In accordance with the criterion of the Organization for Economic Cooperation and Development, our results show that soil brick samples of Zabili and Madajang increases the risk of radiation exposure, thereby the possibility of developing cancer by people living in this environment. Based on these findings, brick samples from Zabili and Madajang are not recommended for construction purposes. All other sample materials have properties that are acceptable for use as building materials in terms of radiation hazard.

scholarly journals The Athens Mobile γ-Spectrometry System (AMESOS)

2019 ◽  
Vol 23 ◽  
pp. 150
Author(s):  
A. Karailias ◽  
V. Lagaki ◽  
C. Katsiva ◽  
A. Kanellakopoulos ◽  
T. J. Mertzimekis ◽  
...  
Keyword(s):  
Absorbed Dose ◽  
In Situ Measurements ◽  
Harsh Environments ◽  
The Public ◽  
Dose Rates ◽  
Field Operation ◽  
Standard Calibration ◽  
Γ Spectrometry ◽  
The University

We report on a new mobile γ-spectrometry system (AMESOS) developed at the University of Athens. The system aims at carrying out in situ measurements to study distributions of NORM and TENORM at harsh environments or where sampling is difficult. AMESOS has been characterized by using standard calibration sources and minerals of known, independently determined, U and Th concentrations. Simulations of the system have been performed with MCNP and Geant4. As a proof of good field operation, AMESOS was deployed in a series of measurements at Mt. Kithaeron, near Athens, extending earlier data and estimating absorbed dose rates that concern the public.

DETERMINATION OF RADON AND NATURAL RADIOACTIVITY CONCENTRATION IN SOME BUILDING MATERIALS USED IN IZMIR, TURKEY

2020 ◽  
Vol 15 (1) ◽  
pp. 107-118
Author(s):  
Daniel Hatungimana ◽  
Caner Taşköprü ◽  
Mutlu İçhedef ◽  
Müslim Murat Saç ◽  
Şemsi Yazıcı ◽  
...  
Keyword(s):  
Natural Radioactivity ◽  
Building Materials ◽  
Gamma Spectroscopy ◽  
Hazard Index ◽  
Absorbed Dose ◽  
Radiation Hazard ◽  
Absorbed Dose Rate ◽  
Dose Rates ◽  
Activity Concentrations ◽  
Materials Used

ABSTRACT The aim of this study is to determine the radon and natural radioactivity concentrations of some building materials and to assess the radiation hazard associated with those mortar materials when they are used in the construction of dwellings. Radon measurements were realized by using LR-115 Type 2 solid state nuclear track detectors. Radon activity concentrations of these materials were found to vary between 130.00 ± 11.40 and 1604.06 ± 40.5 Bq m−3. The natural radioactivity in selected mortar materials was analyzed by using scintillation gamma spectroscopy. The activity concentrations for 226Ra, 232Th and 40K for the studied mortar materials ranged from ND to 48.5 ± 7.0 Bq kg−1, ND to 41.0 ± 6.4 Bq kg−1 and ND to 720.4 ± 26.8 Bq kg−1, respectively. Radium equivalent activities, external and internal hazard indexes, gamma and alpha indexes and absorbed gamma dose rates were calculated to assess the radiation hazard of the natural radioactivity in studied samples. The calculated Raeq values of all samples were found to be lower than the limit of 370 Bq kg−1 set for building materials. The estimated hazard index values were found to be under the unity and the absorbed dose rate values were also below the worldwide average of 84 nGy h−1.

NATURAL RADIOACTIVITY MEASUREMENT AND DOSE ASSESSMENT OF BEACH PLACER SANDS IN THE COASTAL REGION OF TAMIL NADU (INDIA)

2019 ◽  
Vol 184 (3-4) ◽  
pp. 409-412
Author(s):  
N Veerasamy ◽  
S K Sahoo ◽  
K Inoue ◽  
M Fukushi ◽  
H Tsuruoka ◽  
...  
Keyword(s):  
Tamil Nadu ◽  
Coastal Region ◽  
Dose Assessment ◽  
Dose Rates ◽  
Average Value ◽  
Activity Concentrations ◽  
Tamil Nadu State ◽  
Preliminary Study ◽  
Annual Effective Dose Rate ◽  
Ambient Dose

Abstract A preliminary study was carried out to determine the radioactivity concentration of 232Th, 226Ra and 40K in beach placer sands from 13 locations along the coast line of Tamil Nadu state, India. The ambient dose rates varied from 9 to 467 nGy h−1. The activity concentrations of radionuclide 232Th, 226Ra and 40K ranged from 5.2 to 683 Bq kg−1, 13 to 198 Bq kg−1 and 107 to 421 Bq kg−1, respectively. The annual effective dose rate ranges from 27 to 620 μSv y−1 and was higher at seven beaches in comparison to the UNSCEAR annual worldwide average value.

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