title: Is thoron a problem in Swedish dwellings? Results of measurements of concentrations of thoron and its progeny.
abstract: Long-term measurements of thoron progeny concentrations (equilibrium-equivalent thoron concentration) have been carried out in Swedish dwellings with the aim of investigating if thoron and its progeny pose a health risk. Measurements were performed in 93 houses and 25 apartments. In addition to thoron progeny concentration, thoron gas concentration near the wall surface, ambient dose equivalent rate of gamma radiation and radon gas concentration were also measured. The results show that the mean value of thoron progeny was 2.2 Bq m(-3) in houses and 1.6 Bq m(-3) in apartments. Ten per cent of the dwellings (both houses and apartments) had thoron progeny concentrations exceeding 10 Bq m(-3). Thoron progeny concentration is not significantly different in dwellings built of alum shale-based aerated concrete ('blue concrete') than dwellings built of other construction materials. For the dwellings in this study (not representative of the Swedish population), the mean dose estimated due to exposure to thoron was found to be 0.4 mSv y(-1).
authors.affiliation: Swedish Radiation Safety Authority, 171 16 Stockholm, Sweden.
authors.forename: K
authors.initials: K
authors.lastname: Skeppström
authors.affiliation: Swedish Radiation Safety Authority, 171 16 Stockholm, Sweden erik.wahlin@ssm.se.
authors.forename: E
authors.initials: E
authors.lastname: Wåhlin
mesh_terms: D016902:Air Pollution, Indoor / Q000032:analysis / Q000706:statistics & numerical data*; D000398:Air Pollution, Radioactive / Q000032:analysis / Q000706:statistics & numerical data*; D006798:Housing / Q000706:statistics & numerical data*; D015233:Models, Statistical; D011834:Radiation Monitoring / Q000379:methods* / Q000706:statistics & numerical data; D011886:Radon / Q000032:analysis*; D017687:Radon Daughters / Q000032:analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013548:Sweden
chemical_list: D017687:Radon Daughters; D011886:Radon