Estimation of radon emanation coefficient for representative soils in Okinawa, Japan.
Radon ((222)Rn) emanation coefficients for the representative soils distributed in Okinawa Island, Japan, have been estimated empirically. Arithmetic means of the emanation coefficients for dry and moist conditions were calculated to be 0.19 and 0.29, respectively. In Okinawa, the soils are traditionally classified into three types, namely the dark red soils, the residual regosols and the red and yellow soils. The dark red soils have relatively high coefficients. The residual regosols and the red and yellow soils have relatively low coefficients. To investigate the variable factor of the emanation coefficients, analyses of radioactive elements and physical properties have also been performed on the soils. For the dark red soils, the contents of the fine particle and the (226)Ra are relatively higher than those for the other soils. Based on these results, it is suggested that the variation in the radon emanation coefficient is mainly regulated by the (226)Ra concentration, the particle sizes and the water contents of the soils.
Graduate School of Engineering and Sciences, University of the Ryukyus, 1 Senbaru, Nishihara-cho, Okinawa 903-0213, Japan k128606@eve.u-ryukyu.ac.jp.
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Shiroma
Hirosaki University Graduate School of Health Sciences, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan.
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Hosoda
School of Medicine, Fukushima Medical University, 1 Hikariga-oka, Fukushima City 960-1295, Japan.
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Ishikawa
National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan.
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Sahoo
Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan.
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Tokonami
Graduate School of Engineering and Sciences, University of the Ryukyus, 1 Senbaru, Nishihara-cho, Okinawa 903-0213, Japan.
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Furukawa
D000396:Air Pollutants, Radioactive / Q000032:analysis / Q000737:chemistry*; D003198:Computer Simulation; D004058:Diffusion; D007564:Japan; D007700:Kinetics; D008956:Models, Chemical; D011829:Radiation Dosage; D011834:Radiation Monitoring / Q000379:methods; D011886:Radon / Q000032:analysis* / Q000737:chemistry*; D012987:Soil / Q000737:chemistry*; D012990:Soil Pollutants, Radioactive / Q000032:analysis* / Q000737:chemistry*
D000396:Air Pollutants, Radioactive; D012987:Soil; D012990:Soil Pollutants, Radioactive; D011886:Radon