TY - JOUR
T1 - Lung dosimetry of inhaled radon progeny in mice
AU - Sakoda, Akihiro
AU - Ishimori, Yuu
AU - Fukao, Kosuke
AU - Yamaoka, Kiyonori
AU - Kataoka, Takahiro
AU - Mitsunobu, Fumihiro
PY - 2012/11
Y1 - 2012/11
N2 - Biological response of exposure to radon progeny has long been investigated, but there are only few studies in which absorbed doses in lungs of laboratory animals were estimated. The present study is the first attempt to calculate the doses of inhaled radon progeny for mice. For reference, the doses for rats and humans were also computed with the corresponding models. Lung deposition of particles, their clearance, and energy deposition of alpha particles to sensitive tissues were systematically simulated. Absorbed doses to trachea and bronchi, bronchioles and terminal bronchioles, alveolar-interstitial regions, and whole lung were first provided as a function of monodisperse radon progeny particles with an equilibrium equivalent radon concentration of 1 Bq m -3 (equilibrium factor, 0.4 and unattached fraction, 0.01). Based on the results, absorbed doses were then calculated for (1) a reference mine condition and (2) a condition previously used for animal experiments. It was found that the whole lung doses for mice, rats, and humans were 34.8, 20.7, and 10.7 nGy (Bq m -3) -1 h -1 for the mine condition, respectively, while they were 16.9, 9.9, and 6.5 nGy (Bq m -3) -1 h -1 for the animal experimental condition. In both cases, the values for mice are about 2 times higher than those for rats, and about 3 times higher than those for humans. Comparison of our data on rats and humans with those published in the literature shows an acceptable agreement, suggesting the validity of the present modeling for mice. In the future, a more sophisticated dosimetric study of inhaled radon progeny in mice would be desirable to demonstrate how anatomical, physiological, and environmental parameters can influence absorbed doses.
AB - Biological response of exposure to radon progeny has long been investigated, but there are only few studies in which absorbed doses in lungs of laboratory animals were estimated. The present study is the first attempt to calculate the doses of inhaled radon progeny for mice. For reference, the doses for rats and humans were also computed with the corresponding models. Lung deposition of particles, their clearance, and energy deposition of alpha particles to sensitive tissues were systematically simulated. Absorbed doses to trachea and bronchi, bronchioles and terminal bronchioles, alveolar-interstitial regions, and whole lung were first provided as a function of monodisperse radon progeny particles with an equilibrium equivalent radon concentration of 1 Bq m -3 (equilibrium factor, 0.4 and unattached fraction, 0.01). Based on the results, absorbed doses were then calculated for (1) a reference mine condition and (2) a condition previously used for animal experiments. It was found that the whole lung doses for mice, rats, and humans were 34.8, 20.7, and 10.7 nGy (Bq m -3) -1 h -1 for the mine condition, respectively, while they were 16.9, 9.9, and 6.5 nGy (Bq m -3) -1 h -1 for the animal experimental condition. In both cases, the values for mice are about 2 times higher than those for rats, and about 3 times higher than those for humans. Comparison of our data on rats and humans with those published in the literature shows an acceptable agreement, suggesting the validity of the present modeling for mice. In the future, a more sophisticated dosimetric study of inhaled radon progeny in mice would be desirable to demonstrate how anatomical, physiological, and environmental parameters can influence absorbed doses.
KW - Absorbed dose
KW - Inhalation
KW - Lung
KW - Mice
KW - Radon progeny
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U2 - 10.1007/s00411-012-0431-z
DO - 10.1007/s00411-012-0431-z
M3 - Article
C2 - 22915071
AN - SCOPUS:84867850932
VL - 51
SP - 425
EP - 442
JO - Radiation and Environmental Biophysics
JF - Radiation and Environmental Biophysics
SN - 0301-634X
IS - 4
ER -