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Estimation of the Effective Dose Rates from Radon and Thoron during the Chemical Processing of the Black Sand Minerals |
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PP: 61-67 |
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doi:10.18576/jrna/050109
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Author(s) |
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Yassin A. Abdel-Razek,
Osman. A. Desouky,
Ashraf A. Elshenawy,
Amal S. Nasr,
Haitham S. Mohmmed,
Anwar A. Elsayed,
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Abstract |
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| The additive effective dose rates from the radioactive gases radon and thoron and their decay products were evaluated at the laboratories of the minerals; ilmenite, zircon, monazite and rutile. Two types of concentration-effective dose conversion factors were employed; factors resulted from epidemiological studies and those obtained by the Human Respiratory Tract Model (HRTM). Based on HRTM, the additive effective dose rates from radon and thoron gases were found to be 5.84x10-9 and 1.58x10-9 (Sv.h-1.kBq-1), respectively. No significant difference found between the additive effective doses received from thoron gas estimated by the two methods while the value of the additive effective dose rate estimated for radon gas by HRTM factors is almost twice that obtained by the epidemiological factor. The additive effective dose rates received from the radioactive gases radon and thoron and their individual progenies are constants and they are used to estimate the effective dose rates at the environments of these gases directly from the known activity of the processed mineral. On the average, the additive effective dose rate received from each of the three radon decay products 218Po, 214Pb and 214Bi is 1.95x10-9 (Sv.h-1.kBq-1) at the common ventilation rate 1 (h-1).
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