We use a nuclear technique based on the determination of the detection efficiencies of solid state nuclear track detectors CR-39 and LR-115 type II (SSNTDs) for alpha particles emitted from the series of uranium-238 a...We use a nuclear technique based on the determination of the detection efficiencies of solid state nuclear track detectors CR-39 and LR-115 type II (SSNTDs) for alpha particles emitted from the series of uranium-238 and thorium-232 in a phytotherapeutic sample and the measurement of alpha track densities registered on these detectors to assess alpha activities due to uranium-238;thorium-232;radon and thoron in samples of phytotherapeutic preparations consumed by Moroccan adult patients. For modern preparations, the alpha activities due to <sup>238</sup>U, <sup>232</sup>Th and <sup>222</sup>Rn range from 14.27 mBq/kg to 22.02 mBq/kg, from 6.27 mBq/kg to 9.64 mBq/kg and from 14.27 Bq/kg to 22.02 Bq/kg respectively. For classical preparations, the alpha activities due to <sup>238</sup>U, <sup>232</sup>Th and <sup>222</sup>Rn range from 16.73 mBq/kg to 24 mBq/kg, from 7.34 mBq/kg to 10.82 mBq/kg and from 16.73 Bq/kg to 24.72 Bq/kg respectively. A dosimetric model for ingestion has been highlighted to determine committed equivalent dose to different compartments of human gastrointestinal system due to the ingestion of phytotherapeutic preparations by Moroccan adult patients. The maximum overall effective dose due to <sup>238</sup>U, <sup>232</sup>Th, and <sup>222</sup>Rn after the ingestion of the studied phytotherapeutic preparations, was found equal to 38 × 10<sup>-8</sup> S·vy<sup>-1</sup> which is less than the dose limit given by the international commission for radiological protection in it publication 56.展开更多
The Uranium-238 (<sup>238</sup>U), Thorium-232 (<sup>232</sup>Th) families and Potassium-40 (<sup>40</sup>K) are of terrestrial origin and contribute generally to an individual’s e...The Uranium-238 (<sup>238</sup>U), Thorium-232 (<sup>232</sup>Th) families and Potassium-40 (<sup>40</sup>K) are of terrestrial origin and contribute generally to an individual’s external exposure through our presence in this environment. They also contribute to the internal exposure through the ingestion of products and beverages such as water that are close to the earth. The aim of this work is to determine the committed effective dose or Total Indicative Dose (TID) due to gamma radioactivity of the borehole water from the Nord Riviera (NR) well field operated by the Côte d’Ivoire Water Distribution Company (SODECI) for the supply of drinking water to part of the population of Abidjan. In addition, the populations, with their habits, could use these borehole waters directly as drinking water. To this end, water samples from the seven (07) functional boreholes were collected and analyzed on a gamma spectrometry chain, equipped with an HPGe detector in the laboratory of the Radiation Protection Institute (RPI) of the GHANA Atomic Energy Commission (GAEC). The results of the specific activities of <sup>238</sup>U, <sup>232</sup>Th and <sup>40</sup>K obtained were transcribed into TID. As the natural radioactivity of the borehole water is high [1], the TIDs calculated from the activity results of the natural radionuclides<sup>238</sup>U, <sup>232</sup>Th, and <sup>40</sup>K vary for the seven boreholes from 0.150 to 0.166 mSv/yr with an average of 0.161 ± 0.034 mSv/yr. The TID of the control tower, where the borehole water is mixed and treated for household use, is equal to 0.136 ± 0.03 mSv/yr. The TIDs obtained are therefore all slightly greater than the WHO reference dose value of 0.1 mSv/yr. But all remain below the UNSCEAR reference dose of 0.29 mSv/yr.展开更多
Most of the natural occurring radionuclides in both noodles and bread are found to have specific activities below the detectable limit of the high purity germanium (n-type) spectrometer system of the EG&G Ortec C...Most of the natural occurring radionuclides in both noodles and bread are found to have specific activities below the detectable limit of the high purity germanium (n-type) spectrometer system of the EG&G Ortec Company. For dried bread, 40K,137Cs and 60Co are found to be 44.45￣84.52, < 0.012 ￣0.052, < 0.018 ￣0.054 Bq/kg;for noodles, to be 29.55￣64.54, < 0.01 ￣0.069 and < 9.8× 10-3 ￣ 0.074 Bq/kg,respectively. The weighted committed dose equivalents due to the ingestion of 137Csfrom noodles and bread for a male and female adults have been estimated to be 0.5and 0.6μSv, respectively, being less than the values recommended by ICRP.展开更多
Radionuclide contents in imported rice are determined using the EG&G ORTEC photon spectrometer system. Most of the natural radionuclides are found to have specific activities below the detectable limit. 40K has va...Radionuclide contents in imported rice are determined using the EG&G ORTEC photon spectrometer system. Most of the natural radionuclides are found to have specific activities below the detectable limit. 40K has values ranging from 0.104to 32.97 Bq/kg; 137Cs from 0.009 to 0.52 Bq/kg; and 95Zr less than 0.077 Bq/kg. The annual effective dose for a male and a female adult is 18μSv and 12.7μSv, respectively. Both are less than the value recommended by the International Commission of Radiological Protection.展开更多
Objective:To assess the thorium exposure of the mine workers and the public to a typical rare earth mine and estimate the resultant committed effective dose to them.Methods:A total of 79 volunteers were selected in th...Objective:To assess the thorium exposure of the mine workers and the public to a typical rare earth mine and estimate the resultant committed effective dose to them.Methods:A total of 79 volunteers were selected in this survey,including 69 mine workers and 10 local residents living about 4 km away from the mine site.Urinary samples were collected from 79 volunteers,with 65 hair samples from 57 workers and 8 local residents.The thorium concentrations in urinary and hair samples were determined by using inductively coupled plasma mass spectrometry.The committed effective doses were estimated based on the urinary samples collected and the parameters as recommended by ICRP Publication 137.Results:Thorium concentrations in the samples from the workers ranged from 19.0 to 2388.8 ng/g in hair with median of 149.8 ng/g,and in urine 18.3–906.1 ng/L with median of 59.6 ng/L,respectively.The median values of thorium concentrations were 11.8 ng/g in hair and 32.40 ng/L in urine for the public respectively.The thorium concentrations in urinary and hair samples of the workers were not only higher than those of the residents in the local area,but also than those of non-occupationally exposed populations as reported.The median values of committed effective dose were estimated to be 1.51 mSv for the workers and 781μSv for the local residents,respectively.Conclusions:The residents in the local area,and especially the workers,have been subject to long term thorium exposure.More attention should be paid to the radiological hazards of thorium to the workers and local residents.展开更多
文摘We use a nuclear technique based on the determination of the detection efficiencies of solid state nuclear track detectors CR-39 and LR-115 type II (SSNTDs) for alpha particles emitted from the series of uranium-238 and thorium-232 in a phytotherapeutic sample and the measurement of alpha track densities registered on these detectors to assess alpha activities due to uranium-238;thorium-232;radon and thoron in samples of phytotherapeutic preparations consumed by Moroccan adult patients. For modern preparations, the alpha activities due to <sup>238</sup>U, <sup>232</sup>Th and <sup>222</sup>Rn range from 14.27 mBq/kg to 22.02 mBq/kg, from 6.27 mBq/kg to 9.64 mBq/kg and from 14.27 Bq/kg to 22.02 Bq/kg respectively. For classical preparations, the alpha activities due to <sup>238</sup>U, <sup>232</sup>Th and <sup>222</sup>Rn range from 16.73 mBq/kg to 24 mBq/kg, from 7.34 mBq/kg to 10.82 mBq/kg and from 16.73 Bq/kg to 24.72 Bq/kg respectively. A dosimetric model for ingestion has been highlighted to determine committed equivalent dose to different compartments of human gastrointestinal system due to the ingestion of phytotherapeutic preparations by Moroccan adult patients. The maximum overall effective dose due to <sup>238</sup>U, <sup>232</sup>Th, and <sup>222</sup>Rn after the ingestion of the studied phytotherapeutic preparations, was found equal to 38 × 10<sup>-8</sup> S·vy<sup>-1</sup> which is less than the dose limit given by the international commission for radiological protection in it publication 56.
文摘The Uranium-238 (<sup>238</sup>U), Thorium-232 (<sup>232</sup>Th) families and Potassium-40 (<sup>40</sup>K) are of terrestrial origin and contribute generally to an individual’s external exposure through our presence in this environment. They also contribute to the internal exposure through the ingestion of products and beverages such as water that are close to the earth. The aim of this work is to determine the committed effective dose or Total Indicative Dose (TID) due to gamma radioactivity of the borehole water from the Nord Riviera (NR) well field operated by the Côte d’Ivoire Water Distribution Company (SODECI) for the supply of drinking water to part of the population of Abidjan. In addition, the populations, with their habits, could use these borehole waters directly as drinking water. To this end, water samples from the seven (07) functional boreholes were collected and analyzed on a gamma spectrometry chain, equipped with an HPGe detector in the laboratory of the Radiation Protection Institute (RPI) of the GHANA Atomic Energy Commission (GAEC). The results of the specific activities of <sup>238</sup>U, <sup>232</sup>Th and <sup>40</sup>K obtained were transcribed into TID. As the natural radioactivity of the borehole water is high [1], the TIDs calculated from the activity results of the natural radionuclides<sup>238</sup>U, <sup>232</sup>Th, and <sup>40</sup>K vary for the seven boreholes from 0.150 to 0.166 mSv/yr with an average of 0.161 ± 0.034 mSv/yr. The TID of the control tower, where the borehole water is mixed and treated for household use, is equal to 0.136 ± 0.03 mSv/yr. The TIDs obtained are therefore all slightly greater than the WHO reference dose value of 0.1 mSv/yr. But all remain below the UNSCEAR reference dose of 0.29 mSv/yr.
文摘Most of the natural occurring radionuclides in both noodles and bread are found to have specific activities below the detectable limit of the high purity germanium (n-type) spectrometer system of the EG&G Ortec Company. For dried bread, 40K,137Cs and 60Co are found to be 44.45￣84.52, < 0.012 ￣0.052, < 0.018 ￣0.054 Bq/kg;for noodles, to be 29.55￣64.54, < 0.01 ￣0.069 and < 9.8× 10-3 ￣ 0.074 Bq/kg,respectively. The weighted committed dose equivalents due to the ingestion of 137Csfrom noodles and bread for a male and female adults have been estimated to be 0.5and 0.6μSv, respectively, being less than the values recommended by ICRP.
文摘Radionuclide contents in imported rice are determined using the EG&G ORTEC photon spectrometer system. Most of the natural radionuclides are found to have specific activities below the detectable limit. 40K has values ranging from 0.104to 32.97 Bq/kg; 137Cs from 0.009 to 0.52 Bq/kg; and 95Zr less than 0.077 Bq/kg. The annual effective dose for a male and a female adult is 18μSv and 12.7μSv, respectively. Both are less than the value recommended by the International Commission of Radiological Protection.
文摘Objective:To assess the thorium exposure of the mine workers and the public to a typical rare earth mine and estimate the resultant committed effective dose to them.Methods:A total of 79 volunteers were selected in this survey,including 69 mine workers and 10 local residents living about 4 km away from the mine site.Urinary samples were collected from 79 volunteers,with 65 hair samples from 57 workers and 8 local residents.The thorium concentrations in urinary and hair samples were determined by using inductively coupled plasma mass spectrometry.The committed effective doses were estimated based on the urinary samples collected and the parameters as recommended by ICRP Publication 137.Results:Thorium concentrations in the samples from the workers ranged from 19.0 to 2388.8 ng/g in hair with median of 149.8 ng/g,and in urine 18.3–906.1 ng/L with median of 59.6 ng/L,respectively.The median values of thorium concentrations were 11.8 ng/g in hair and 32.40 ng/L in urine for the public respectively.The thorium concentrations in urinary and hair samples of the workers were not only higher than those of the residents in the local area,but also than those of non-occupationally exposed populations as reported.The median values of committed effective dose were estimated to be 1.51 mSv for the workers and 781μSv for the local residents,respectively.Conclusions:The residents in the local area,and especially the workers,have been subject to long term thorium exposure.More attention should be paid to the radiological hazards of thorium to the workers and local residents.
