Natural Radioactivity, Radiological Hazard and Petrographical Studies on Aswan Granites Used as Building Materials in Egypt

Abstract

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.

Distribution of Radionuclides and Radiological Health Assessment in Seih-Sidri Area, Southwestern Sinai

“…Several indices were developed based on the mass fractions found in this work for 40 K (C K ), 232 Th (C Th ), and 226 Ra (C Ra ) to quantify the radiological danger for people exposed to the radiations generated by the granite rocks [ 10 , 32 , 33 , 34 ]. The absorbed dose rate in the air (D) could be calculated using the following formula: D (nGy h −1 ) = 0.0417 C K + 0.604 C Th + 0.462 C Ra [ 33 ].…”

“…Several indices were developed based on the mass fractions found in this work for 40 K (C K ), 232 Th (C Th ), and 226 Ra (C Ra ) to quantify the radiological danger for people exposed to the radiations generated by the granite rocks [ 10 , 32 , 33 , 34 ]. The absorbed dose rate in the air (D) could be calculated using the following formula: D (nGy h −1 ) = 0.0417 C K + 0.604 C Th + 0.462 C Ra [ 33 ]. The following equation gives the external hazard index (Hex), which is frequently used to assess the radiation dose rate brought on by external exposure to gamma radiation from natural radionuclides in soil/rock samples: H ex is equal to [ 33 ] = C K 4810 + C Th 259 + C Ra 370 ≤ 1.…”

“…The absorbed dose rate in the air (D) could be calculated using the following formula: D (nGy h −1 ) = 0.0417 C K + 0.604 C Th + 0.462 C Ra [ 33 ]. The following equation gives the external hazard index (Hex), which is frequently used to assess the radiation dose rate brought on by external exposure to gamma radiation from natural radionuclides in soil/rock samples: H ex is equal to [ 33 ] = C K 4810 + C Th 259 + C Ra 370 ≤ 1. For the radiation threat to be negligible, the estimated average external hazard index must be less than unity.…”

“…The Ra estimated error percentages range from 1 to 5 percent. The precision of the energy calibration approach, which takes into account the likely interference of each nuclide in each peak site, and the estimated error of 1 to 5 decide the findings [ 30 , 31 , 32 , 33 ]. The minimal detection K is 0.1 percent.…”

An In-Depth Examination of the Natural Radiation and Radioactive Dangers Associated with Regularly Used Medicinal Herbs

“…γ (E) is the absolute efficiency of detector. The equations used to calculate the radiological hazards have been discussed in detail in our previous works [22][23][24][25][26][27][28][29][30]. The error associated with every calculation was measured by the standard deviation (SD) equation.…”