Igneous and sedimentary rocks contain an amount of natural radioactivity (NORM). U-238, Th-232 and their decay products, and K-40 are important sources of gamma-radiation. Knowledge of the radionuclide content of rock...Igneous and sedimentary rocks contain an amount of natural radioactivity (NORM). U-238, Th-232 and their decay products, and K-40 are important sources of gamma-radiation. Knowledge of the radionuclide content of rocks is necessary to estimate the exposure of the population to the radiation. Many types of rocks are used in building and industries, thus the radiation detection is important, it provides a baseline map of levels of the radioactivity in the study region. The purpose of this study is to evaluate the activity concentrations of the natural radionuclides (U-238 (Ra-226), Th-232 and K-40) and the fallout nuclide (Cs-137) (if found) in thirty samples of igneous and sedimentary rocks of Al-Atawilah (Al-Baha). The samples were collected and prepared during 2018/2019, and analyzed with a good experimental instrument (High energy resolution γ-ray spectroscopy with HPGe detector), also these rock samples were analyzed with X-ray fluorescence to subdivided these rocks based on the major oxides proportions contained of each sample. The mean activity concentrations of naturally radionuclides were found in the igneous rock samples varied depending on the type of the igneous rock. For sedimentary rock samples, the activity concentrations were found high for quartz sandstone sample, which may be due to its high proportion of SiO<sub>2</sub> and K<sub>2</sub>O. The estimated mean values of absorbed dose rate are within the permissible limit value. The findings indicate high dose level values in granite (rhyolite) and most of diorite (andesite) igneous rock samples while gabbro (basalt) igneous rock samples (except for one sample) record low levels of dose rate. All sedimentary rock samples have low dose rate (except for the quartz sand-stone sample).展开更多
In this work, gamma-ray spectroscopy based on semiconductor hyper pure germanium (HPGe) detector was used to evaluate the activity concentrations of the natural radionuclides (U-238 (Ra-226), Th-232 and K-40) and the ...In this work, gamma-ray spectroscopy based on semiconductor hyper pure germanium (HPGe) detector was used to evaluate the activity concentrations of the natural radionuclides (U-238 (Ra-226), Th-232 and K-40) and the fallout nuclide (Cs-137) for thirty samples of igneous and sedimentary rocks of Al-Atawilah (Al-Baha). The mean values of the activity concentrations of U-238 (Ra-226), Th-232, K-40 and Cs-137 in the igneous samples are found as (11.0, 11.50, 1172.71, 1.47) Bq/Kg respectively. In the sedimentary rocks, the mean values of the activity concentrations of the natural radionuclides (U-238 (Ra-226), Th-232 and K-40) and the fallout nuclide (Cs-137) equal to (12.04, 13.18, 1131.36, 1.60) Bq/Kg respectively. The averages of radiological hazards (<em>Ra</em><sub><em>eq</em></sub>, <em>H</em><sub><em>ex</em></sub> and <em>I</em><sub><em><span style="white-space:nowrap;"><span style="white-space:nowrap;">γ</span></span></em></sub>) were calculated and found to be within the UNSCEAR permissible limit values (370 Bq/kg for <em>Ra</em><sub><em>eq</em></sub>, and 1 for <em>H</em><sub><em>ex</em></sub> and <em>I</em><sub><em><span style="white-space:nowrap;"><span style="white-space:nowrap;">γ</span></span></em></sub>), except for a slight increase of average value of <em>I</em><sub><em><span style="white-space:nowrap;"><span style="white-space:nowrap;">γ</span></span></em></sub> in the igneous rock samples (1.36). The results indicate that the dose rate values depend on the kind of rocks (high in some igneous rock samples, and most of sedimentary rock samples have low dose rate). The activities of naturalnuclides were predicted and simulated in T time using a written MATLAB R2020a script based on the average activity concentrations and respective half-lives of U-238 and Th-232 series, and K-40, this is to evaluate the future effects of natural radionuclides on the population and estimate the human inputs in the future.展开更多
This study has been carried out to determine the concentrations mg/Kg of the toxic elements (Al, Hg, Cd, Pb, U, Th, and As) and essential elements (K, Sn, Ca, Ni, Cu, Fe, Co, and Mn) using inductively coupled plasma o...This study has been carried out to determine the concentrations mg/Kg of the toxic elements (Al, Hg, Cd, Pb, U, Th, and As) and essential elements (K, Sn, Ca, Ni, Cu, Fe, Co, and Mn) using inductively coupled plasma optical emission spectrometer, and the radionuclides concentration levels of (<sup>238</sup>U, <sup>226</sup>Ra, <sup>232</sup>Th, <sup>40</sup>K and <sup>137</sup>Cs) using a high purity germanium spectrophotometer in ten of the most common fish samples collected from local store in Jeddah city, Saudi Arabia during 2014. The results showed that, the concentrations of the elements (Al, Hg, Pb and Cu) in all fish samples were not detected or below the detection limit. The concentrations of metals (Cd, U, Th, As, K, Sn, Ca, Ni, Fe, Co, and Mn) were below the recommended limit by the international organizations. The estimated metal dose (EDI) values for daily average consumption were lower than the recommended values by FAO/WHO, and hazard indices (HI) in fish samples were below safety levels for human consumption (HI 1), then this increase is to be of concern for fish consumer. The measured concentrations in (Bq/Kg) dry weight of natural radionuclides <sup>238</sup>U, <sup>226</sup>Ra, <sup>232</sup>Th, <sup>40</sup>K and fallout <sup>137</sup>Cs in fish samples were calculated. The results show that the activities in fish samples were of no risk to public health. The total average annual effective dose μSv/y due to intake of <sup>238</sup>U, <sup>226</sup>Ra, <sup>232</sup>Th and <sup>40</sup>K from the ingestion of the fish samples were estimated to be 6.07 for infants (≤5 Y), 22.88 and 45.03 for children (5 - 10 Y and 10 - 15 Y) and 56.26 for adults (≥17 y), which are lower than the allowed value (1 mSv). The contribution of 137Cs is nearly negligible. This study could be useful as a baseline data for toxic, essential metals, and radiation, exposure.展开更多
The activity concentrations of natural radionuclides <sup>226</sup>Ra, <sup>232</sup>Th and <sup>40</sup>K, were measured in (16) sandstone samples collected from two regions of Sau...The activity concentrations of natural radionuclides <sup>226</sup>Ra, <sup>232</sup>Th and <sup>40</sup>K, were measured in (16) sandstone samples collected from two regions of Saudi Arabia, Region 1 (Al Wajh on Red Sea coast and Al Ula north-East of Medina), Region 2 (North of Al Ula and Az Zabirah, North-West of Hail) by (HPGe gamma spectrometer). The activity concentration average values of the radionuclides <sup>226</sup>Ra, <sup>232</sup>Th, and <sup>40</sup>K in the sandstone samples (Region 1) ranged from 10.97 ± 0.43, 27.68 ± 0.37 and 64.56 ± 0.74 Bq/kg respectively. These values are less than the international values reported by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR, 2000), in (Region 2), average values ranged from 2465.49 ± 0.00, 2042.00 ± 0.00 and 2259.65 ± 0.64 Bq/kg respectively. These values are higher than the values reported by (UNSCEAR, 2000). Average values of radium equivalent activity Ra<sub>eq</sub> (Bq/Kg), absorbed dose rate D (nGy/h), annual effective radiation dose D<sub>eff</sub> (mSv/y), External index (H<sub>ex</sub>) and Internal index (H<sub>in</sub>) were in (region 1) 21.13, 27.22, 11.75, 0.07 and 0.10 respectively, in (region 2) 5775.19, 1787.78, 846.58, 11.57 and 15.64 respectively. These results are lower (except annual effective radiation dose) in (region 1) and higher in (region 2) than the world recommended values by (UNSCEAR, 2000). Also, samples were analyzed by Atomic Absorption spectrometer (AAS) for Al, Ca, Fe, K, Mg and Bi in % elements concentrations. Average value in (region 1) (Al Wajh and Al Ula) are 4.42, 0.41, 1.37, 0.04 and 0.03, (in region 2) (N. Al Ula and Az Zabirah) are 12.50, 10.05, 1.01, 1.19, 0.04 respectively. Classifications of sandstone depend on the content of these elements. These results are important for the safety of dwellers and user of sandstone in constructions.展开更多
Fifteen Porcelain and Ceramic Dinner Wares samples (collected from local commercial suppliers—Jeddah Saudi Arabia) were studied applying X-Ray Diffraction and Atomic Absorption techniques were used to study the Chemi...Fifteen Porcelain and Ceramic Dinner Wares samples (collected from local commercial suppliers—Jeddah Saudi Arabia) were studied applying X-Ray Diffraction and Atomic Absorption techniques were used to study the Chemical, Mineral, Compositions Concentrations (of Some Metals). In addition, the Natural Radioactivity measurements of <sup>226</sup>Ra, <sup>232</sup>Th and <sup>40</sup>K, was used by a high-purity germanium (HPGe) detector. X-ray diffraction results showed that the major mineral constituents of 15 samples were quartz (SiO<sub>2</sub>) (except one), minor and trace elements vary from sample to sample. Atomic absorption spectroscopy results of the concentrations for (Al, Pb, Bi, U, Th and K) in (ppm) showed that Al<sub>2</sub>O average was 10.3 (ppm) (10%) less than the acceptable value. PbO, its average was 1.65 ppm which was slightly greater than the allowed value 1.35 ppm. Bi concentrations for all samples were lower than (DL < 10). For most samples U, concentrations were lower than (DL < 5) except samples C9 and C11. Th concentrations ranged from LDL (<1 to 52.88) and were much greater than the acceptable value 7.24 ppm except samples P1, P2, P4. The potassium concentration average was greater than the acceptable value. The average concentrations of <sup>238</sup>U, <sup>232</sup>Th and <sup>40</sup> K were (83.83, 91.05 and 751.07) Bq/kg dry. The radium equivalent activity concentration <em>Ra</em><sub><em>eq</em></sub> (Bq/kg) (302.61) was less than recommended value (370), gamma dose rate <em>D</em> (nGy/h) average (140.15) was much higher than the recommended value (60) (UNSCEER). <em>D</em><sub><em>eff</em></sub> (mSv/year) and <em>H</em><sub><em>ix</em></sub> were below the published admissible limit ≤ 1 and the risk is negligible. This study offers needed information for consumers at exposure risk and is useful to be found in terms of radiation protection.展开更多
文摘Igneous and sedimentary rocks contain an amount of natural radioactivity (NORM). U-238, Th-232 and their decay products, and K-40 are important sources of gamma-radiation. Knowledge of the radionuclide content of rocks is necessary to estimate the exposure of the population to the radiation. Many types of rocks are used in building and industries, thus the radiation detection is important, it provides a baseline map of levels of the radioactivity in the study region. The purpose of this study is to evaluate the activity concentrations of the natural radionuclides (U-238 (Ra-226), Th-232 and K-40) and the fallout nuclide (Cs-137) (if found) in thirty samples of igneous and sedimentary rocks of Al-Atawilah (Al-Baha). The samples were collected and prepared during 2018/2019, and analyzed with a good experimental instrument (High energy resolution γ-ray spectroscopy with HPGe detector), also these rock samples were analyzed with X-ray fluorescence to subdivided these rocks based on the major oxides proportions contained of each sample. The mean activity concentrations of naturally radionuclides were found in the igneous rock samples varied depending on the type of the igneous rock. For sedimentary rock samples, the activity concentrations were found high for quartz sandstone sample, which may be due to its high proportion of SiO<sub>2</sub> and K<sub>2</sub>O. The estimated mean values of absorbed dose rate are within the permissible limit value. The findings indicate high dose level values in granite (rhyolite) and most of diorite (andesite) igneous rock samples while gabbro (basalt) igneous rock samples (except for one sample) record low levels of dose rate. All sedimentary rock samples have low dose rate (except for the quartz sand-stone sample).
文摘In this work, gamma-ray spectroscopy based on semiconductor hyper pure germanium (HPGe) detector was used to evaluate the activity concentrations of the natural radionuclides (U-238 (Ra-226), Th-232 and K-40) and the fallout nuclide (Cs-137) for thirty samples of igneous and sedimentary rocks of Al-Atawilah (Al-Baha). The mean values of the activity concentrations of U-238 (Ra-226), Th-232, K-40 and Cs-137 in the igneous samples are found as (11.0, 11.50, 1172.71, 1.47) Bq/Kg respectively. In the sedimentary rocks, the mean values of the activity concentrations of the natural radionuclides (U-238 (Ra-226), Th-232 and K-40) and the fallout nuclide (Cs-137) equal to (12.04, 13.18, 1131.36, 1.60) Bq/Kg respectively. The averages of radiological hazards (<em>Ra</em><sub><em>eq</em></sub>, <em>H</em><sub><em>ex</em></sub> and <em>I</em><sub><em><span style="white-space:nowrap;"><span style="white-space:nowrap;">γ</span></span></em></sub>) were calculated and found to be within the UNSCEAR permissible limit values (370 Bq/kg for <em>Ra</em><sub><em>eq</em></sub>, and 1 for <em>H</em><sub><em>ex</em></sub> and <em>I</em><sub><em><span style="white-space:nowrap;"><span style="white-space:nowrap;">γ</span></span></em></sub>), except for a slight increase of average value of <em>I</em><sub><em><span style="white-space:nowrap;"><span style="white-space:nowrap;">γ</span></span></em></sub> in the igneous rock samples (1.36). The results indicate that the dose rate values depend on the kind of rocks (high in some igneous rock samples, and most of sedimentary rock samples have low dose rate). The activities of naturalnuclides were predicted and simulated in T time using a written MATLAB R2020a script based on the average activity concentrations and respective half-lives of U-238 and Th-232 series, and K-40, this is to evaluate the future effects of natural radionuclides on the population and estimate the human inputs in the future.
文摘This study has been carried out to determine the concentrations mg/Kg of the toxic elements (Al, Hg, Cd, Pb, U, Th, and As) and essential elements (K, Sn, Ca, Ni, Cu, Fe, Co, and Mn) using inductively coupled plasma optical emission spectrometer, and the radionuclides concentration levels of (<sup>238</sup>U, <sup>226</sup>Ra, <sup>232</sup>Th, <sup>40</sup>K and <sup>137</sup>Cs) using a high purity germanium spectrophotometer in ten of the most common fish samples collected from local store in Jeddah city, Saudi Arabia during 2014. The results showed that, the concentrations of the elements (Al, Hg, Pb and Cu) in all fish samples were not detected or below the detection limit. The concentrations of metals (Cd, U, Th, As, K, Sn, Ca, Ni, Fe, Co, and Mn) were below the recommended limit by the international organizations. The estimated metal dose (EDI) values for daily average consumption were lower than the recommended values by FAO/WHO, and hazard indices (HI) in fish samples were below safety levels for human consumption (HI 1), then this increase is to be of concern for fish consumer. The measured concentrations in (Bq/Kg) dry weight of natural radionuclides <sup>238</sup>U, <sup>226</sup>Ra, <sup>232</sup>Th, <sup>40</sup>K and fallout <sup>137</sup>Cs in fish samples were calculated. The results show that the activities in fish samples were of no risk to public health. The total average annual effective dose μSv/y due to intake of <sup>238</sup>U, <sup>226</sup>Ra, <sup>232</sup>Th and <sup>40</sup>K from the ingestion of the fish samples were estimated to be 6.07 for infants (≤5 Y), 22.88 and 45.03 for children (5 - 10 Y and 10 - 15 Y) and 56.26 for adults (≥17 y), which are lower than the allowed value (1 mSv). The contribution of 137Cs is nearly negligible. This study could be useful as a baseline data for toxic, essential metals, and radiation, exposure.
文摘The activity concentrations of natural radionuclides <sup>226</sup>Ra, <sup>232</sup>Th and <sup>40</sup>K, were measured in (16) sandstone samples collected from two regions of Saudi Arabia, Region 1 (Al Wajh on Red Sea coast and Al Ula north-East of Medina), Region 2 (North of Al Ula and Az Zabirah, North-West of Hail) by (HPGe gamma spectrometer). The activity concentration average values of the radionuclides <sup>226</sup>Ra, <sup>232</sup>Th, and <sup>40</sup>K in the sandstone samples (Region 1) ranged from 10.97 ± 0.43, 27.68 ± 0.37 and 64.56 ± 0.74 Bq/kg respectively. These values are less than the international values reported by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR, 2000), in (Region 2), average values ranged from 2465.49 ± 0.00, 2042.00 ± 0.00 and 2259.65 ± 0.64 Bq/kg respectively. These values are higher than the values reported by (UNSCEAR, 2000). Average values of radium equivalent activity Ra<sub>eq</sub> (Bq/Kg), absorbed dose rate D (nGy/h), annual effective radiation dose D<sub>eff</sub> (mSv/y), External index (H<sub>ex</sub>) and Internal index (H<sub>in</sub>) were in (region 1) 21.13, 27.22, 11.75, 0.07 and 0.10 respectively, in (region 2) 5775.19, 1787.78, 846.58, 11.57 and 15.64 respectively. These results are lower (except annual effective radiation dose) in (region 1) and higher in (region 2) than the world recommended values by (UNSCEAR, 2000). Also, samples were analyzed by Atomic Absorption spectrometer (AAS) for Al, Ca, Fe, K, Mg and Bi in % elements concentrations. Average value in (region 1) (Al Wajh and Al Ula) are 4.42, 0.41, 1.37, 0.04 and 0.03, (in region 2) (N. Al Ula and Az Zabirah) are 12.50, 10.05, 1.01, 1.19, 0.04 respectively. Classifications of sandstone depend on the content of these elements. These results are important for the safety of dwellers and user of sandstone in constructions.
文摘Fifteen Porcelain and Ceramic Dinner Wares samples (collected from local commercial suppliers—Jeddah Saudi Arabia) were studied applying X-Ray Diffraction and Atomic Absorption techniques were used to study the Chemical, Mineral, Compositions Concentrations (of Some Metals). In addition, the Natural Radioactivity measurements of <sup>226</sup>Ra, <sup>232</sup>Th and <sup>40</sup>K, was used by a high-purity germanium (HPGe) detector. X-ray diffraction results showed that the major mineral constituents of 15 samples were quartz (SiO<sub>2</sub>) (except one), minor and trace elements vary from sample to sample. Atomic absorption spectroscopy results of the concentrations for (Al, Pb, Bi, U, Th and K) in (ppm) showed that Al<sub>2</sub>O average was 10.3 (ppm) (10%) less than the acceptable value. PbO, its average was 1.65 ppm which was slightly greater than the allowed value 1.35 ppm. Bi concentrations for all samples were lower than (DL < 10). For most samples U, concentrations were lower than (DL < 5) except samples C9 and C11. Th concentrations ranged from LDL (<1 to 52.88) and were much greater than the acceptable value 7.24 ppm except samples P1, P2, P4. The potassium concentration average was greater than the acceptable value. The average concentrations of <sup>238</sup>U, <sup>232</sup>Th and <sup>40</sup> K were (83.83, 91.05 and 751.07) Bq/kg dry. The radium equivalent activity concentration <em>Ra</em><sub><em>eq</em></sub> (Bq/kg) (302.61) was less than recommended value (370), gamma dose rate <em>D</em> (nGy/h) average (140.15) was much higher than the recommended value (60) (UNSCEER). <em>D</em><sub><em>eff</em></sub> (mSv/year) and <em>H</em><sub><em>ix</em></sub> were below the published admissible limit ≤ 1 and the risk is negligible. This study offers needed information for consumers at exposure risk and is useful to be found in terms of radiation protection.
