scholarly journals Background Radiation from 238U, 232Th, and 40K in Bells Area and Canaan City, Ota, Nigeria

2020 ◽  
Vol 8 (E) ◽  
pp. 678-684
Author(s):  
M. R. Usikalu ◽  
C. A. Enemuwe ◽  
R. O. Morakinyo ◽  
M. M. Orosun ◽  
T. A. Adagunodo ◽  
...  
Keyword(s):  
Cancer Risk ◽  
Activity Concentration ◽  
Background Radiation ◽  
Natural Radionuclides ◽  
Radiation Risk ◽  
Absorbed Dose ◽  
Dose Rates ◽  
University Of Technology ◽  
The Mean ◽  
Absorbed Dose Rates

Natural radionuclides are present in every constituent of the environment. Monitoring of environmental radionuclides is very vital to avoid exposure above the threshold limit. Due to this, the background radiation from 238U, 232Th, and 40K of Bell University of Technology and Canaan Land City was determined from 20 sample points each in the two areas using RS230 Gamma Spectrometer. The mean activity concentration of 40K, 238U, and 232Th for Bells University of Technology was 442.66 Bq/kg, 41.98 Bq/kg, and 48.35 Bq/Kg, respectively. In Canaan City, mean activity concentration of 40K, 238U, and 232Th was 373.65 Bq/kg, 18.85 Bq/kg, and 67.22 Bq/kg, respectively. The mean absorbed dose rates recorded by the spectrometer directly were 70.03 nGy/h and 66.65 nGy/h, while that estimated from the activity concentration were 67.06 and 64.89 nGy/h for Bells University and Canaan City, respectively. The measured and estimated absorbed dose rates were higher than the safe limit of 57 nGy/h. The mean values of other radiological parameters estimated, except that of the gamma index and excess lifetime cancer risk were lower when compared to the recommended limit. It could be concluded that the possibility of suffering any radiation risk is low in these two areas, but there is possibility of cancer risk for someone that has stayed in the area for 70 years and above.

EVALUATION OF INDOOR/OUTDOOR GAMMA EXPOSURE RATES AND EXCESS LIFE TIME CANCER RISK IN DIFFERENT CITIES OF PAKISTAN

2020 ◽  
Vol 190 (4) ◽  
pp. 355-363
Author(s):  
Jahan Zeb ◽  
Mohammad Wasim ◽  
Muhammad Awais ◽  
Asad Ullah ◽  
Talat Iqbal ◽  
...  
Keyword(s):  
Cancer Risk ◽  
Dose Rate ◽  
Absorbed Dose ◽  
Life Time ◽  
Absorbed Dose Rate ◽  
Detailed Measurement ◽  
Dose Rates ◽  
The Mean ◽  
Azad Kashmir ◽  
Indoor And Outdoor

Abstract This study presents a detailed measurement of indoor and outdoor terrestrial gamma radiation levels in different cities of Pakistan. The measurements covered dwellings in 27 cities, covering all provinces and region of Azad Kashmir. Most of the houses were of attached type, made of brick walls and concrete roofs. The measurements were made by a handheld radiation survey meter containing Geiger–Muller tube. The average absorbed dose rate in air was 100 ± 32 nGy h−1 for indoor and 74 ± 30 nGy h−1 for outdoor. The population-weighted mean terrestrial dose rates were 90 nGy h−1 for indoor and 78 nGyh−1 for outdoor. The ratio of indoor to outdoor absorbed dose rate was 1.5 as compared to 1.3 for the world average. The estimated average annual effective dose rate was 0.58 ± 0.18 mSv a−1 and the mean excess life time cancer risk was 2.0 × 10−3.

IMPACT ON ABSORBED DOSE RATE IN AIR IN KANTO REGION BY FUKUSHIMA DAIICHI NUCLEAR POWER PLANT ACCIDENT

2019 ◽  
Vol 184 (3-4) ◽  
pp. 500-503
Author(s):  
K Inoue ◽  
M Arai ◽  
H Tsuruoka ◽  
K Saito ◽  
M Fujisawa ◽  
...  
Keyword(s):  
Dose Rate ◽  
Nuclear Power ◽  
Absorbed Dose ◽  
Ground Level ◽  
Absorbed Dose Rate ◽  
Artificial Radionuclides ◽  
Dose Rates ◽  
The Mean ◽  
Absorbed Dose Rates ◽  
Kanto Region

Abstract Absorbed dose rates in air were measured for the whole area of the Kanto region in 2015, 2016 and 2017 (n = 31 147). The mean absorbed dose rates in air for each prefecture measured by car-borne surveys were from 44 to 67 nGy h−1 (13–289 nGy h−1). The absorbed dose rate in air from artificial radionuclides (134Cs + 137Cs) measured by fixed-point observation (n = 507) was from 1 to 14 nGy h−1 (0–105 nGy h−1), and meaning that the contribution ratios of 134Cs and 137Cs were 3–22%. The deposited location of artificial radionuclides was less than 1000 m from ground level and depended on the topography, wind direction and precipitation field.

scholarly journals Determination of Activity Concentration of Natural Radionuclides and Radiation Hazards’ Assessment of Building Materials in High Background Radiation Areas of Homa and Ruri, Kenya

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Willis Otieno Gor Odongo ◽  
Margaret Chege ◽  
Nadir Hashim ◽  
Shinji Tokonami ◽  
Kranrod Chutima ◽  
...  
Keyword(s):  
Building Materials ◽  
Activity Concentration ◽  
Background Radiation ◽  
Natural Radionuclides ◽  
High Background ◽  
Dose Rates ◽  
Radium Equivalent ◽  
Materials Used ◽  
The One

The areas around Homa and Ruri hills in Homa Bay County in Kenya are associated with high background radiation levels. The activity concentration of the natural radionuclides (226Ra, 232Th, and 40K) in earthen building materials used in the areas of Homa and Ruri hills has been measured using a NaI (Tl) detector in this work. The measured values of radioactivity concentrations are used to estimate the associated radiological risk. The earthen building material samples from Ruri registered relatively high 232Th concentration values averaging 1094 ± 55 Bq/kg, nearly three times those of the samples from Homa. 226Ra level was not significantly different in both regions with Homa reporting 129 ± 10 Bq/kg and Ruri 111 ± 6 Bq/kg. 40K was however higher in the samples from Homa by an approximate factor of 2 relative to those from Ruri where the activity concentration was 489 ± 24 Bq/kg. The radium equivalents for 226Ra, 232Th, and 40K in the samples from Ruri were 111 ± 9, 1564 ± 125, and 38 ± 3 Bq/kg, while in Homa, the values were 129 ± 10, 570 ± 46, and 69 ± 5 Bq/kg, respectively. The calculated value of total radium equivalent in Ruri was 1713 ± 137 Bq/kg which was two times higher than that of Homa. 232Th contributed about 74% and 91% to the total radium equivalent in Homa and Ruri, respectively; thus, it was the one with the largest contribution to radiation exposure in both regions. The average indoor annual effective dose rates were 1.74 ± 0.14 and 3.78 ± 0.30 mSv/y in Homa and Ruri, respectively, both of which were above the recommended safety limit of 1 mSv/y.

scholarly journals Radiation Risk Assessment of Soil in Idomi, Cross River State, Nigeria

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
N. O. Chiaghanam ◽  
C. C. Nzotta ◽  
L. B. Enweani
Keyword(s):  
Effective Dose ◽  
Background Radiation ◽  
Radiation Risk ◽  
Hazard Index ◽  
Absorbed Dose ◽  
Soil Samples ◽  
Cross River ◽  
Cross River State ◽  
Activity Concentrations ◽  
The Mean

In this thesis work, the radiation risk from soil samples in Idomi community located at Yakurr Local Government Area of Cross River State, Nigeria was studied. This was because of an earlier study that revealed the presence of high radioactivity in the area. This study aim to determine the background radiation levels, estimate their effective dose, the mean activity concentrations of the radionuclide and the radiological implications of the radioactivity levels in Idomi. Thirty (30) soil samples were collected and analyzed. The baseline average annual outdoor effective dose, mean activity concentration, gamma absorbed dose and radiological hazard index were studied. Results from this study indicate that three (3) radionuclide namely 40K, 238U and 232Th were present in the soil samples analyzed.  The mean activity concentrations of 40K, 238U and 232Th in the soil samples were 506.13±9.30, 41.14±3.59 and 84.52±20.88 Bqkg-1 respectively.  The calculated mean external and internal hazard index was 0.62 and 0.71 respectively. The calculated mean gamma index was 0.86. The Raeq in the soil samples was 227.34 Bqkg-1. The calculated absorbed gamma dose from the sample was 110.31nGy-1 and a mean annual outdoor effective dose of 1.35mSvy-1.  Compared with global average values of 10-200nGyh-1, 2.4 mSvy-1and Raeq of 370BqKg-1 they can be said to be within the normal range. From this study, the chances of occurrence of health effects from exposure to natural terrestrial gamma radiation in Idomi can be said to be low.  This may be possible if the baseline levels obtained from this study can be kept constant by keeping the environment free of radioactive pollution.

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.

scholarly journals Influences of Absorbed Dose Rate on the Mechanical Properties and Fiber–Matrix Interaction of High-Density Polyethylene-Based Carbon Fiber Reinforced Thermoplastic Irradiated by Electron-Beam

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3012
Author(s):  
Se Kye Park ◽  
Dong Yun Choi ◽  
Duyoung Choi ◽  
Dong Yun Lee ◽  
Seung Hwa Yoo
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Carbon Fiber ◽  
Dose Rate ◽  
High Density Polyethylene ◽  
Absorbed Dose ◽  
High Density ◽  
Absorbed Dose Rate ◽  
Dose Rates ◽  
Absorbed Dose Rates

In this study, a high-density polyethylene (HDPE)-based carbon fiber-reinforced thermoplastic (CFRTP) was irradiated by an electron-beam. To assess the absorbed dose rate influence on its mechanical properties, the beam energy and absorbed dose were fixed, while the absorbed dose rates were varied. The tensile strength (TS) and Young’s modulus (YM) were evaluated. The irradiated CFRTP TS increased at absorbed dose rates of up to 6.8 kGy/s and decreased at higher rates. YM showed no meaningful differences. For CFRTPs constituents, the carbon fiber (CF) TS gradually increased, while the HDPE TS decreased slightly as the absorbed dose rates increased. The OH intermolecular bond was strongly developed in irradiated CFRTP at low absorbed dose rates and gradually declined when increasing those rates. X-ray photoelectron spectroscopy analysis revealed that the oxygen content of irradiated CFRTPs decreased with increasing absorbed dose rate due to the shorter irradiation time at higher dose rates. In conclusion, from the TS viewpoint, opposite effects occurred when increasing the absorbed dose rate: a favorable increase in CF TS and adverse decline of attractive hydrogen bonding interactions between HDPE and CF for CFRTPs TS. Therefore, the irradiated CFRTP TS was maximized at an optimum absorbed dose rate of 6.8 kGy/s.

Radiation-induced color centers in LiF for dosimetry at high absorbed dose rates

1980 ◽  
Vol 175 (1) ◽  
pp. 17-18 ◽  
Author(s):  
William L. McLaughlin ◽  
Arne Miller ◽  
Stuart C. Ellis ◽  
Arthur C. Lucas ◽  
Barbara M. Kapsar
Keyword(s):  
Absorbed Dose ◽  
Color Centers ◽  
Dose Rates ◽  
Radiation Induced ◽  
Absorbed Dose Rates
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