title: Measurements of thoron progeny concentration using a potential alpha-energy monitor in Japan.
abstract: It is reported that thoron concentration in Japanese dwellings may be higher than in other dwellings. Therefore, in order to assess the risk for indoor thoron progeny, the portable potential alpha-energy monitor has been developed. The monitor detects alpha-particles from the 212Po collected on the filter using a piece of cellulose nitrate film. The detection efficiency of the alpha-particles has been estimated by Monte Carlo calculation. From the results of measurements, the mean indoor thoron progeny concentration in the dwellings was 1.5 Bq m-3 (ECTn), and ranged from 0.04 to 8.2 Bq m-3. The effects of three typical interior walls (soil-based plaster, concrete, and modern materials) on the thoron progeny supply were considered. The mean annual effective dose equivalent was 0.45 mSv.
authors.affiliation: Chubu Electric Power Company, Inc., Nagoya, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yamasaki
authors.forename: T
authors.initials: T
authors.lastname: Iida
mesh_terms: D000396:Air Pollutants, Radioactive / Q000032:analysis; D016902:Air Pollution, Indoor / Q000032:analysis; D000512:Alpha Particles; D055592:Biophysical Phenomena; D001703:Biophysics; D006798:Housing; D006801:Humans; D007564:Japan; D011834:Radiation Monitoring / Q000295:instrumentation*; D011886:Radon / Q000032:analysis*
chemical_list: D000396:Air Pollutants, Radioactive; D011886:Radon