scholarly journals Radiological Hazard Evaluation of Some Egyptian Magmatic Rocks Used as Ornamental Stone: Petrography and Natural Radioactivity

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7290
Author(s):  
El Saeed R. Lasheen ◽  
Mohammed A. Rashwan ◽  
Hamid Osman ◽  
Sultan Alamri ◽  
Mayeen U. Khandaker ◽  
...  

Magmatic rocks represent one of the most significant rocks due to their abundance, durability and appearance; they can be used as ornamental stones in the construction of dwellings. The current study is concerned with the detailed petrography and natural radioactivity of seven magmatic rocks. All are commercial granitic rocks and are identified as black Aswan, Nero Aswan, white Halayeb, Karnak, Verdi, red Hurghada and red Aswan. Their respective mineralogical compositions are classified as porpheritic granodiorite, granodiorite, tonalite, monzogranite, syenogranite, monzogranite and syenogranite. A total of nineteen samples were prepared from these seven rock types in order to assess their suitability as ornamental stones. Concentrations of 226Ra, 232Th and 40K radionuclides were measured using NaI (Tl) scintillation gamma-ray spectrometry. Among the studied magmatic rocks, white Halayeb had the lowest average values of 226Ra (15.7 Bq/kg), 232Th (4.71 Bq/kg) and 40K (~292 Bq/kg), all below the UNSCEAR reported average world values or recommended reference limits. In contrast, the other granitic rocks have higher values than the recommended limit. Except for the absorbed dose rate, other radiological hazard parameters including radium equivalent activity, annual effective dose equivalent, external, and internal hazard indices reflect that the White Halyeb rocks are favorable for use as ornamental stone in the construction of luxurious and high-demand residential buildings.

Symmetry ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 746 ◽  
Author(s):  
Saifeldin Siddeeg ◽  
Mohamed Suliman ◽  
Faouzi Ben Rebah ◽  
Wissem Mnif ◽  
Amel Ahmed ◽  
...  

Various commercially imported ceramic materials used in the building of Sudanese dwellings were examined in order to determine their natural radioactivity and radiological hazard parameters. In this context, twenty-five different consignments were sampled and analyzed using (3″ × 3″) sodium iodide gamma spectrometry system NaI(Tl). The identified average activity concentrations of 238U, 232Th, and 40K were 183 ± 70, 51 ± 44, and 238 ± 77 Bq/kg dry-weights, respectively. A positive correlation between 238U and 232Th in the investigated samples was identified from the observed significant correlation (R2 = 0.8). Interestingly, a low Th/U ratio (~0.3) was recorded, which could be related to the systematic loss of thorium during the fabrication process. The measured activity concentrations for these radionuclides were comparable with the reported data obtained from similar materials used in other countries showing similarity in ceramic materials used in buildings. Five different radiation indices, such as the average radium equivalent (Raeq), the absorbed dose rate (D), the annual effective dose equivalent (AEDE), the external hazard index (Hex), and the radioactivity level index (lγ), which indicate hazardous radiation, were estimated from these measurements. The obtained results revealed average values of 274 ± 106 Bq/kg, 125 ± 48 nGy/h, 1.23 ± 0.48 mSv/y, 0.74 ± 0.29, and 0.94 ± 0.37, for Raeq, D, AEDE, Hex, and lγ, respectively. The mean values of Raeq and Hex were in good agreement with the international limits, while the means of D and lγ were higher than the universal values. Calculated AEDE in about 60% of the samples exceeded the universal limit of 1 mSv/y for the public exposure (maximum value of 2.16 mSv/y). The investigated parameters were in the same range for the majority of imported samples; however, they were slightly higher than the locally produced ceramic, highlighting the importance of monitoring imported materials for their radioactivity contents.


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.


2012 ◽  
Vol 12 (2) ◽  
pp. 395-401 ◽  
Author(s):  
D. Pereira ◽  
L. Neves ◽  
A. Pereira ◽  
M. Peinado ◽  
J. A. Blanco ◽  
...  

Abstract. In the area of Trujillo (Extremadura, Spain) we have found a variety of striking bluish and secondary yellow granites outcropping within the Plasenzuela pluton. They are all quarried under different names and are characterized by leucocratic minerals in which a bluish phosphate is dispersed throughout the rock. Their physical and mechanical properties make these granites a perfect option for most applications as ornamental rocks. Within the pluton the radiological background is fairly homogeneous, with no significant differences between the gamma ray fluxes of the different facies. U (6.4 ± 0.51 ppm), Th (2.9 ± 0.47 ppm) and K2O (4.32 ± 0.26%) contents determined in the laboratory by gamma-ray spectrometry from representative samples are in good accordance with fast in situ measurements carried out with the same technique and also with conventional chemical analysis. Estimated activities for K-40, Ra-226 and Th-232 were, on average, 1022 ± 36 Bq kg−1, 84 ± 9 Bq kg−1 and 6.8 ± 1.6 Bq kg−1. On the basis of these results, the I index of EU technical document 112 was determined, with an average result of 0.66 ± 0.03. This suggests that the rock can be used with no restrictions for all types of construction purposes. Striking differences were observed between the blue facies and the yellow facies in radon exhalation tests from crushed material (0.03 Bq kg−1 vs. 0.20 Bq kg−1). Since both granites have similar uranium contents (6.3 ppm and 6.5 ppm, respectively), these results can probably be explained in terms of important differences in the mineralogical distribution of this chemical element, radon emanation being enhanced in the yellow facies. However, due to the ordinary use as ornamental stone, the yellow facies does not present a radiological risk in terms of excess effective dose due to internal exposure to radon.


2021 ◽  
pp. 55-65
Author(s):  
Jemila Mussa Ali ◽  
Salha D. Y. Alsaadi ◽  
Abdulwahhab Alkuwafi

The natural radioactivity of 15 ceramic samples imported from Italy, China, and Egypt to the local market of Benghazi city-Libya, was measured by the means of a gamma-ray spectroscopy system with an HPG detector. The activity concentrations of 226Ra, 232Th and 40K were ranged from 75.75 to 85.63 Bq.kg-1, 44.10to 65.20 Bq.kg-1 and 819.52 to 959.27 Bq.kg-1, respectively. The radium equivalent, external hazard index, gamma radiation index, absorbed dose rate, annual effective dose, and cancer risk factor were calculated using the above measurements in order to assess the radiological hazard associated with the studied ceramic samples. The average values of these radiological indices for the ceramic samples were found to be; 232.29 Bq.kg-1, 0.63, 1.71, 107.11 nGy.h-1, 0.13 mSv.y-1 and 0.43, respectively. In general, the average value of radium equivalent for ceramic samples is not exceeded the recommended value of 370 Bq.kg-1, the external hazard index is lower than unity, and for all samples the annual effective dose below the recommended world limits. On the other hand, some radiological hazard indices were reported to be higher than the recommended world limits. The ceramic samples concerned in this study might be recommended to be utilized as building materials for dwelling construction. Keywords: Natural radioactivity; Radiological hazard; Absorbed dose rate; HPGe detector; Ceramic


2021 ◽  
Vol 56 (4) ◽  
pp. 659-672
Author(s):  
Sk. A. K. Arafin ◽  
Md. Sapan Bhuiyan ◽  
Jannatul Ferdous ◽  
M. Ashraful Hoque ◽  
A. K. M. Rezaur Rahman ◽  
...  

The study aimed to investigate natural radioactivity levels and Transfer Factors of natural radionuclides from soil to some plants in Chittagong, Bangladesh. The concentrations of naturally occurring and anthropogenic radionuclides in soil and plants were measured in this work to determine the absorbed dose rate and the transfer factors of radionuclides from soil to plant. Plants (Spinach and Vegetables) and corresponding soil samples were collected from three different locations in Chittagong (Nasirabad, Sitakunda, and Halda Agrotechnology), and the concentrations of activity of natural radionuclides were measured using gamma-ray spectrometry. The average absorbed dose rate in the soil of Nasirabad, Sitakunda, and Halda Agrotechnology are 49.84 nGyh-1, 37.4 nGyh-1, and 45.6 nGyh-1. The average transfer factor from soil to plants, recorded for 238U, 232Th, and 40K of these study areas, are 0.461, 0.400, and 3.10, respectively. The ratio of soil to plant transfer factor for the present study compared with some previous work. The Transfer Factor of 40K gives some high value but does not exceed the limit of the different published values. Because there are no existing databases for the natural radioactivity in soil and plants from Chittagong, Bangladesh, our results are establishing a database for the Chittagong, Bangladesh soil and plants. This data may be used as a database for further investigation for the betterment of public health.


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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