scholarly journals Spatial Distributions and Risk Assessment of the Natural Radionuclides in the Granitic Rocks from the Eastern Desert, Egypt

Minerals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 386
Author(s):  
Hany El-Gamal ◽  
Essam Sidique ◽  
Mervat El-Haddad

This paper investigates the distribution of four natural radioisotopes 238U, 226Ra, 232Th and 40K in one hundred twenty-five granitic samples covering sixteen mountainous areas situated at the northern, central and southern parts of the Eastern Desert of Egypt (EDE). The concentrations of the examined radioisotopes in the collected samples were recognized utilizing a HPGe detector based gamma spectrometry. The average concentrations of these radioisotopes were higher when compared with the worldwide reference values. The radiation risk indicators including the radium equivalent activity index (Raeq), external and internal hazard indicators (Hex and Hin), external and internal level indicators (Iα and Iγ), absorbed dose rate (ADR), annual effective dose rate (AEDR), annual gonadal dosage equivalent (AGDE), and excess lifetime cancer risk (ELCR), associated with these radioisotopes have been calculated and compared with their recommended global values and safety limits. These indicators showed that the granites from most studied areas exceeded the universal standards pointing to the difficulty of using them as building materials. This study together with future investigations will serve to develop an essential database for future environmental monitoring surveys.

2021 ◽  
Vol 11 (14) ◽  
pp. 6471
Author(s):  
Nasser M. Moghazy ◽  
Amira M. El-Tohamy ◽  
Mona M. Fawzy ◽  
Hamdy A. Awad ◽  
Hesham M. H. Zakaly ◽  
...  

The present study was carried out on commercial types of Aswan granite used as building and decorative materials. Nearly 29 granitic rocks samples from 11 classes (black Aswan, red Aswan, dark Rosa, light Rosa, yellow Verdi, grey Shirka, Gandolla, Forsan, red Nefertiti, Royal, and white Halayeb) were collected from three stations near Aswan city for petrographical description and assessment of natural radioactivity. The petrographical study of granites was conducted by polarized-light microscope in order to determine their mineralogical composition and investigate their texture; the activity of the natural radionuclides 238U, Ra226, 232Th, and 40K was measured by gamma-ray spectrometry with a NaI(Tl) detector. The average values of the activities, 52.2 Bq kg−1, 57.8 Bq kg−1, 31.2 Bq kg−1, and 1055.7 Bq kg−1 of U-238, Th-232, Ra-226, and K-40, respectively, were higher than that the world average values of 35 Bq kg−1, 30 Bq kg−1 and 400 Bq kg−1 for 226Ra, 232Th, and 40K, respectively, according to the recommended levels from UNSCEAR reports. The minimum and maximum values obtained were compared with the value ranges from other locations in the Eastern Desert, highlighting the fact that that the maximum values obtained in this work are higher than those in other areas. According to the radiological hazards indices results, most samples lie in the permissible level ranges, suggesting their favorability for use as building materials. In contrast to that, some samples have some environmental parameters higher than the international levels, indicating their unsuitability as building materials.


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.


2020 ◽  
Vol 65 (1) ◽  
pp. 1-18
Author(s):  
Branislava Mitrovic ◽  
Dragana Todorovic ◽  
Jelena Ajtic ◽  
Borjana Vranjes

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.


2020 ◽  
Vol 24 (3) ◽  
pp. 435-442 ◽  
Author(s):  
M. Atipo ◽  
O. Olarinoye ◽  
B. Awojoyogbe ◽  
M. Kolo

Mineral mining and milling can be a source of national economic and technological development. However, mining of minerals has been confirmed to disturb the natural distribution of radioisotopes in the soil, air and water bodies in the biota. In an attempt to evaluate the radiological burden resulting from tin mining activities at Rayfield-Du area of Jos, the background gamma-radiation level in the mine was measured via a well calibratedhand-held dosimeter placed at 1 m above ground level. The mean absorbed dose rate, annual effective dose rate and excess lifetime cancer risk for the mine was 0.83 μSvh-1; 1.44 mSv-1 and 0.005 respectively. Generally, dose rates were higher in the mine pits and processing areas as compared to administrative areas of the mine. The mean measured dose rate and calculated dose parameters for the mine were all high when compared to the regulatory limit for public exposure. The potential of developing radiation-induced health defects as a result of high radiation absorbed dose rate by the miners and dwellers around the mine is highly probable.  Keywords: Gamma-radiation; mine; absorbed dose rate; radiation exposure.


2018 ◽  
Vol 788 ◽  
pp. 51-55
Author(s):  
Daina Riekstina ◽  
Tamara Krasta ◽  
Ruta Švinka

Natural radionuclides K-40, and Th-232, U-238 (Ra-226) decay chain products contained in building materials are the main source of radiation dose received by population and the only source of indoor radiation exposure. Present work contains results of the study of natural radionuclide activity level in clay, clay ceramics and silica bricks used in Latvia. Obtained data show that radionuclide content in different clay products can differ up to five times. However, determined activity index values for all tested materials, except fireproof bricks, were below radionuclide concentration level permitted by EU and Latvian national regulations. Comparison with analogous data from other North European and Baltic countries shows that average concentrations of natural radionuclides and activity index values for clay and clay bricks used in Latvia are on the same level as in other countries, except Sweden.


2010 ◽  
Vol 58 (spe4) ◽  
pp. 25-32 ◽  
Author(s):  
Wagner de S. Pereira ◽  
Alphonse Kelecom ◽  
Delcy de A. Py Júnior

A methodology was developed for converting the activity concentration of radionuclides (Bq kg-1) into absorbed dose rate (Gy y-1), aiming an approach to environmental radioprotection based on the concept of standard dose limit. The model considers only the internal absorbed dose rate. This methodology was applied to the cubera snapper fish (Lutjanus cyanopterus, Cuvier, 1828) caught off the coast of Ceará. The natural radionuclides considered were uranium-238, radium-226, lead-210, thorium-232 and radium-228. The absorbed dose rates were calculated for individual radionuclides and the type of emitted radiation. The average dose rate due to these radionuclides was 5.36 µGy y-1, a value six orders of magnitude smaller than the threshold value of absorbed dose rate used in this study (3.65 10³ mGy y-1), and similar to that found in the literature for benthic fish. Ra-226 and U-238 contributed 67% and 22% of the absorbed dose rate, followed by Th-232 with 10%. Ra-228 and Pb-210, in turn, accounted for less than 1% of the absorbed dose rate. This distribution is somewhat different from that reported in the literature, where the Ra-226 accounts for 86% of the absorbed dose rate.


2017 ◽  
Vol 27 (3) ◽  
pp. 193
Author(s):  
Sonexay Xayheungsy ◽  
Le Hong Khiem ◽  
Le Dai Nam

The natural radioactivity due to presence of 226Ra, 232Th and 40K radionuclides in Lao PDR cements was measured for first time using a gamma-spectrometry with HPGe detector. Two different types of cement produced by 4 local cement companies in Lao PDR have been investigated.  The specific radioactivity of 226Ra, 232Th and 40K in the investigated samples ranged from 24.83 ± 1.18  to 54.39 ± 5.90  Bq kg-1 with a mean of 37.76 ± 10.71 Bq kg-1, 6.63 ± 1.59 to 21.17 ± 0.48 Bq kg-1 with a mean of 13.77 ± 5.85 Bq kg-1 and 43.28 ± 7.68 to 168.70 ± 3.34 Bq kg-1 with a mean of 116.07 ± 47.50 Bq kg-1, respectively. The radium equivalent activity (Raeq), the gamma-index, the external and internal hazard indices, Absorb Dose Rate in Air (D) and Annual Effective Dose Equivalent (AEDE) were estimated for the radiation hazard of the natural radioactivity in all cement samples. The obtained results were compared with the corresponding values for cement of different countries. The calculated Raeq values of Lao PDR samples are lower than the limit of 370 Bq kg-1 set fo building materials. The mean indoor absorbed dose rate is slightly lower than the population-weighted average of 84 nGy h-1 while the corresponding effective dose was 79% less than the dose ft of 1 mSv y-1. The results obtained in this study show no significant radiological hazards arising from using Lao PDR cement for construction of houses.


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 ◽  
Author(s):  
Petr Kuča ◽  
Peter Bossew

<p><strong>Using Safecast data for estimating ambient dose rate in cities around the world</strong></p><p>Petr KUČA<sup>1 </sup>and Peter Bossew<sup>2</sup></p><p><sup>1</sup> National Radiation Protection Institute (SURO), Praha, Czech Republic </p><p><sup>2</sup> German Federal Office for Radiation Protection, Berlin</p><p> </p><p>Safecast [1] is a citizen science project, aimed to environmental monitoring. Its main activity is measuring ambient dose rate (ADR) all over the world. Motivated by the Fukushima NPP accident in March 2011, the project started soon after, and since, numerous citizens have contributed, carrying monitors with them.</p><p>In this presentation, the Safecast project is introduced together with its standard instrument for ADR measurement, called bGeigie Nano. We discuss matters of quality assurance connected to data generation mainly by citizens who are generally no trained metrologists, and consequently, interpretation problems of Safecast data.</p><p>The freely accessible data, currently (January 2020) over 120 million observations, were used to calculate mean ADR in various cities around the world where sufficient data is available. The resulting geographical pattern mainly reflects the variability of dose rate from terrestrial radiation, which is controlled by the one of geochemistry, namely the concentrations of uranium, thorium and potassium. Further influence comes from cosmic radiation, natural radionuclides in the air (a small contribution) and in a few cases, from anthropogenic radiation caused by nuclear fallout.</p><p>In some cities at high altitude, such as Cusco (Peru), Nairobi (Kenia) or Denver (USA), secondary cosmic radiation clearly contributes strongly to ADR. In low to medium altitude, cosmic dose rate varies relatively little, so that it contributes little to the geographical pattern. Apart from the regional geological background, ADR is generated by building materials typical for an urban environment. Mean terrestrial ADR in cities around the world ranges between several 10 nSv/h and several 100 nSv/h. Anthropogenic radiation contributes little, except close to areas affected by the Chernobyl and Fukushima accidents. However, one can argue that also radiation from building materials, although originating from natural radionuclides, is anthropogenic, as buildings are anthropogenic objects and the choice of building materials is an anthropogenic one.</p><p>We show maps displaying mean ADR for a number of cities. Geology and in some cases, altitude above sea level are clearly reflected in these maps. Besides, we address statistical issues related to spatial dispersion of ADR and of data clustering as resulting from varying and heterogeneous sampling density. Finally, we discuss merits of the Safecast project as well as inevitable limitations.</p><p>[1] www.safecast.org ; Brown, A., Franken, P., Bonner, S., Dolezal, N., Moross, J. (2016): Safecast: successful citizen-science for radiation measurement and communication after Fukushima. Journal of Radiological Protection, 36 (2), S82 – S101; doi:10.1088/0952-4746/36/2/s82</p>


Sign in / Sign up

Export Citation Format

Share Document