Radon Migration Process and Its Influence Factors; Review

Hassan, Nabil M.; Hosoda, Masahiro; Ishikawa, Tetsuo; Sorimachi, Atsuyuki; Sahoo, Sarata Kumar; Tokonami, Shinji; Fukushi, Masahiro

doi:10.5453/jhps.44.218

Cited by 81 publications

(40 citation statements)

References 92 publications

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“…Among the factors that infl uence the exhalation rate of radon, the following factors need to be mentioned: the amount of water present in the building material, its porosity, grain size, temperature, atmospheric pressure, material sample geometry, and so on [18]. One of the possible ways to measure the rate of exhalation from the material sample is by the continuous monitoring of the radon activity in air as a function of time, according to Eq.…”

Section: Measurements Of Radon Exhalation Ratementioning

confidence: 99%

Exhalation rate of radon-222 from concrete and cement mortar

et al. 2018

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The main sources of radon in the air of dwellings are soil, building materials, and groundwater. This study aimed to determine the exhalation rate of 222Rn from samples made of concrete and cement mortars, as well as to evaluate by means of gamma spectrometry the hazard indexes associated with other radionuclides present in the studied samples of building materials. The results obtained allowed the comparison of the exhalation rate of radon using theoretical calculations based on one-dimensional and three-dimensional models. Measurements of the activity concentration of radon in air was performed by AlphaGuard radon detector. Furthermore, obtained results were compared with the measurements performed inside the concrete test cells. These test cells were built with the aim of simulating a dwelling in small dimensions and to evaluate indoor radon activity associated with concrete. Consequently, the obtained results of radon exhalation rate, in becquerel per meter squared per hour, for the concrete was 2.55 ± 0.03 Bq·h−1·m−2 for the 1D model and 0.461 ±0.008 Bq·h−1·m−2 for the 3D model. The exhalation rate of radon, for the cement mortar was 1.58 ± 0.03 Bq·h−1·m−2 for the 1D model and 0.439 ± 0.011 Bq·h−1·m−2 for the 3D model. The indoor concentration of 222Rn from the test cell was 112 ± 9 Bq/m3. These values were below the limit of 300 Bq/m3 recommended by the International Commission on Radiological Protection (ICRP) and <148 Bq/m3, the limit recommended by the US Environmental Protection Agency (US EPA). Even so, these values should be the subject of concern since that activity is related only to the contribution of concrete walls.

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Section: Measurements Of Radon Exhalation Ratementioning

confidence: 99%

Exhalation rate of radon-222 from concrete and cement mortar

et al. 2018

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“…For soil grains from 0.6 to 1 mm, one can assume the value of the radon emanation coeffi cient in soil  equal to 0.1-0.15 ([17] and references herein). Radon diffusion coeffi cient D varies in a range (4.8 × 10 [3,17] and the average soil density was assumed as 1.6 × 10 3 kg·m -3 [17]. Theoretically calculated E Rn were in a range from 8.4 to 14 mBq·m ·s −1 for soils worldwide [3].…”

Section: Resultsmentioning

confidence: 99%

“…For the latter, there are theoretical publications examining radon diffusion length and samples geometries (volumes, masses, thickness of layers, etc.) in several materials [3] and possible sources of uncertainties [20]. During in situ measurements, other factors play a role, such as meteorological conditions (air temperature, air pressure) [4,17] and a precise and repeatable mounting of the accumulation chamber on studied soil during measurements.…”

Section: Resultsmentioning

confidence: 99%

“…Radon diffusion coeffi cient D varies in a range (4.8 × 10 [3,17] and the average soil density was assumed as 1.6 × 10 3 kg·m -3 [17]. Theoretically calculated E Rn were in a range from 8.4 to 14 mBq·m ·s −1 for soils worldwide [3]. Exhalation rate studies concern soil and rocks in situ measurements and building materials measurements performed in laboratories.…”

Section: Resultsmentioning

confidence: 99%

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Investigation of the influence of chamber construction parameters on radon exhalation rate

et al. 2016

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Radon exhalation from ground is a process dependent on the emanation and migration of radon through ambient air. Most studies on radon exhalation from soil were performed regarding the influence of meteorological and soil parameters. As radon exhalation rate can be affected by the internal properties of the sample, it may also be influenced by the exhalation chamber geometry such as volume-to-area (V/S) ratio or other construction parameters. The measurements of radon exhalation from soil were made using different constructions of accumulation chamber and two types of radon monitors: RAD7 (Durridge) and AlphaGUARD PQ2000PRO (Genitron). The measurements were performed on one site in two locations and approximately at the same time. The first tests did not show the correlations of exhalation rate values and the chamber’s construction parameters and their geometrical dimensions. However, when examining the results, it seems that there are still too many factors that might have affected the process of radon exhalation. The future experiments are planned to be conducted in controlled laboratory conditions.

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“…Consequently, the -particle dose is delivered directly to the bronchial tissue, creating a potential for radiogenic lung cancer [6][7][8]. Therefore, radiation released from fertilizers has a potential of causing cancers in individuals exposed to significant levels so that monitoring of natural radioactivity in fertilizers has an importance from the viewpoint of radiation protection [9,10].…”

Section: Introductionmentioning

confidence: 99%

Comparison of Natural Radioactivity of Commonly Used Fertilizer Materials in Egypt and Japan

Hassan

Chang

Tokonami

2017

Journal of Chemistry

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Specific activities of238 U, 232 Th, and 40 K in the environment have been redistributed by the use of fertilizers in agriculture so their concentrations in fertilizer materials should be measured to identify the safe utilization of fertilizers. In the present work, the specific activities of these radionuclides in five commonly used fertilizers in Egypt and five fertilizers used in Japan were measured by HPGe and -ray spectrometry. The average values of 238 U, 232 Th, and 40 K in Japanese fertilizers were less than their values in Egyptian fertilizers but both had some samples with specific activities greater than the recommended limiting values. The radiological hazards of radium equivalent activity (Ra eq ), external ( ex ) and internal ( in ) indexes, alpha and gamma indexes, and annual effective dose, due to the presence of these radionuclides, were calculated and compared with each other.

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Radon Migration Process and Its Influence Factors; Review

Cited by 81 publications

References 92 publications

Exhalation rate of radon-222 from concrete and cement mortar

Exhalation rate of radon-222 from concrete and cement mortar

Investigation of the influence of chamber construction parameters on radon exhalation rate

Comparison of Natural Radioactivity of Commonly Used Fertilizer Materials in Egypt and Japan

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