title: Radon and thoron inhalation doses in dwellings with earthen architecture: Comparison of measurement methods.
abstract: The radioactive noble gas radon (222Rn) and its decay products have been considered a health risk in the indoor environment for many years because of their contribution to the radiation dose of the lungs. The radioisotope thoron (220Rn) and its decay products came into focus of being a health risk only recently. The reason for this is its short half-life, so only building material can become a significant source for indoor thoron. In this study, dwellings with earthen architecture were investigated with different independent measurement techniques in order to determine appropriate methods for reliable dose assessment of the dwellers. While for radon dose assessment, radon gas measurement and the assumption of a common indoor equilibrium factor often are sufficient, thoron gas has proven to be an unreliable surrogate for a direct measurement of thoron decay products. Active/time-resolved but also passive/integrating measurements of the total concentration of thoron decay products demonstrated being precise and efficient methods for determining the exposure and inhalation dose from thoron and its decay products. Exhalation rate measurements are a useful method for a rough dose estimate only if the exhalation rate is homogeneous throughout the house. Before the construction of a building in-vitro exhalation rate measurements on the building material can yield information about the exposure that is to be expected. Determining the unattached fraction of radon decay products and even more of thoron decay products leads to only a slightly better precision; this confirms the relative unimportance of the unattached thoron decay products due to their low concentration. The results of this study thereby give advice on the proper measurement method in similar exposure situations.
authors.affiliation: Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Radiation Protection, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany. Electronic address: omeisenberg@bfs.de.
authors.forename: Oliver
authors.initials: O
authors.lastname: Meisenberg
authors.affiliation: Bhabha Atomic Research Centre, Radiological Physics and Advisory Division, Mumbai 400 085, India. Electronic address: rosaline@barc.gov.in.
authors.forename: Rosaline
authors.initials: R
authors.lastname: Mishra
authors.affiliation: Bhabha Atomic Research Centre, Radiological Physics and Advisory Division, Mumbai 400 085, India.
authors.forename: Manish
authors.initials: M
authors.lastname: Joshi
authors.affiliation: Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Radiation Protection, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Gierl
authors.affiliation: Bhabha Atomic Research Centre, Radiological Physics and Advisory Division, Mumbai 400 085, India.
authors.forename: Rajeswari
authors.initials: R
authors.lastname: Rout
authors.affiliation: Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Radiation Protection, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany.
authors.forename: Lu
authors.initials: L
authors.lastname: Guo
authors.affiliation: Bhabha Atomic Research Centre, Radiological Physics and Advisory Division, Mumbai 400 085, India.
authors.forename: Tarun
authors.initials: T
authors.lastname: Agarwal
authors.affiliation: Bhabha Atomic Research Centre, Radiological Physics and Advisory Division, Mumbai 400 085, India.
authors.forename: Sandeep
authors.initials: S
authors.lastname: Kanse
authors.affiliation: Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Radiation Protection, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany.
authors.forename: Josef
authors.initials: J
authors.lastname: Irlinger
authors.affiliation: Bhabha Atomic Research Centre, Radiological Physics and Advisory Division, Mumbai 400 085, India. Electronic address: bsapra@barc.gov.in.
authors.forename: Balvinder K
authors.initials: BK
authors.lastname: Sapra
authors.affiliation: Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Radiation Protection, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany. Electronic address: tschiersch@helmholtz-muenchen.de.
authors.forename: Jochen
authors.initials: J
authors.lastname: Tschiersch
mesh_terms: D000396:Air Pollutants, Radioactive / Q000032:analysis*; D016902:Air Pollution, Indoor / Q000032:analysis* / Q000706:statistics & numerical data; D001108:Architecture; D004781:Environmental Exposure; D006207:Half-Life; D006798:Housing; D019570:Inhalation Exposure / Q000706:statistics & numerical data*; D011834:Radiation Monitoring / Q000379:methods*; D011886:Radon / Q000032:analysis*; D017687:Radon Daughters
chemical_list: D000396:Air Pollutants, Radioactive; D017687:Radon Daughters; D011886:Radon
keywords: Clay dwelling; Indoor exposure; Inhalation dose assessment; Measurement method; Radon; Thoron