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 ◽  
...  

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.

2013 ◽  
Vol 3 (2) ◽  
pp. 232-240 ◽  
Author(s):  
Heiyam Najy Majeed ◽  
Ali . K. Hasan

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.


1970 ◽  
Vol 33 (1) ◽  
pp. 117-130 ◽  
Author(s):  
KA Kabir ◽  
SMA Islam ◽  
MM Rahman

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


2016 ◽  
Vol 31 (2) ◽  
pp. 165-172 ◽  
Author(s):  
Shaaban Harb ◽  
Noor Ahmed ◽  
Wael Badawy ◽  
Nagwa Saad

The activity concentrations of natural radionuclides (226Ra, 232Th, and 40K) for a set of 31 agricultural soil samples from the Nile River banks in the area of El-Sebaiya city, Aswan Governorate, Egypt were measured by gamma-spectrometry. The study revealed that the average activity concentrations of natural radionuclides 226Ra, 232Th, and 40K were 23.2 ? 2.8Bq/kg, 21.1 ? 2.8 Bq/kg, and 218.6 ? 3.7 Bq/kg, respectively. The obtained results of the activity concentrations are within the range of values reported for neighbouring areas in Egypt. The values obtained for the hazard indices and the representative level index in all sampling sites were lower than unity, showing that there is no significant risk arising from the exposure to the soil in the studied area. The absorbed dose rate and annual effective dose in air outdoors and indoors were calculated from 226Ra, 232Th, and 40K in soil, the average values being 32.64 nGy/h, 40.06 ?Sv, and 160.25 ?Sv, respectively. The absorbed dose rate at the eastof El-Sebaiya city is higher than that obtained for the west because of higher concentrations of tri-calcium phosphate in the soil. The studied area is not significantly affected by the industrial activities, except for a few isolated spots.


2020 ◽  
Vol 189 (2) ◽  
pp. 234-241 ◽  
Author(s):  
Jahan Zeb ◽  
Mohammad Wasim ◽  
Sardar A Shah ◽  
Safia Khanam ◽  
Hajira Tahir ◽  
...  

Abstract Chemical phase and distribution of natural radionuclides (226Ra, 232Th and 40K) were determined for sand samples collected from ten different beaches of Karachi. All samples, except one, were identified with major and minor phases as SiO2 and CaCO3, respectively. The average activity concentrations were 24.9, 25.0 and 239 Bq kg−1 for 226Ra, 232Th and 40K, respectively. Including all samples, the average radium equivalent activity was 79.1 Bq kg−1. The external and internal radiation hazard indices and representative level index were all found below unity. The average air absorbed dose rate at 1 m above the sand due to the natural radionuclides was 18.3 nGy h−1, which was less than the world average for soil. The corresponding annual effective dose rate was 22.4 μSv y−1. It was found that Raeq had positive significant correlation with the amount of quartz present at the beaches.


2018 ◽  
Vol 184 (1) ◽  
pp. 5-11
Author(s):  
C M Alonso-Hernández ◽  
A L Toledo-Sibello ◽  
A Guillén-Arruebarrena ◽  
R Sibello-Hernández ◽  
Y Morera-Gómez ◽  
...  

Abstract The natural radioactivity and the associated radiation hazards of soils from the Cumanayagua Granitoide-Granitic massif in the central south of Cuba have been studied. Mass activities of the natural radionuclides 238U, 232Th and 40K varied in the ranges 10.4–33, 4.6–21.7 and 381–1201 Bq kg−1, respectively. The radium equivalent activity (91.4 ± 22.1 Bq kg−1), absorbed dose rate (45.6 ± 11.1 nGy h−1), annual effective dose rate (56.1 ± 13.7 μSv y−1) and the external hazard index (0.25 ± 0.06) have been calculated and compared with the internationally approved values. According to these results, the area can be regarded as an area with normal natural background radiation and may not pose radiological risks to the inhabitants owing to harmful effects of ionizing radiation from the natural radionuclides in soils. This study provides background radioactivity concentrations in Cumanayagua Granitoide area and generate a baseline data for radiological mapping of Cuba in the future.


2018 ◽  
Vol 53 (4) ◽  
pp. 265-278 ◽  
Author(s):  
S. Penabei ◽  
D. Bongue ◽  
P. Maleka ◽  
T. Dlamini ◽  
Saïdou ◽  
...  

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.


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