Stochastic dosimetry model for radon progeny in the rat lung.
The stochastic dosimetry model presented here considers the distinctly asymmetric, stochastic branching pattern reported in morphometric measurements. This monopodial structure suggests that an airway diameter is a more appropriate morphometric parameter to classify bronchial dose distributions for inhaled radon progeny than the commonly assigned airway generation numbers. Bronchial doses were calculated for the typical exposure conditions reported for the Pacific Northwest National Laboratory rat inhalation studies, yielding an average bronchial dose of 7.75 mGy WLM(-1). If plotted as functions of airway generations, the resulting dose distributions are highest in the central bronchial airways, while significantly decreasing towards peripheral generations. However, if plotted as functions of airway diameters, doses are much more uniformly distributed among bronchial airways. The comparison between rat and human lungs indicates that dose conversion coefficients for the rat lung are higher than the corresponding values for the human lung by a factor of 1.34 for the experimental PNNL exposure conditions, and of 1.25 for typical human indoor conditions.
Division of Physics and Biophysics, Department of Materials Research and Physics, University of Salzburg, Hellbrunner Str. 34, 5020 Salzburg, Austria.
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Winkler-HeiI
Division of Physics and Biophysics, Department of Materials Research and Physics, University of Salzburg, Hellbrunner Str. 34, 5020 Salzburg, Austria werner.hofmann@sbg.ac.at.
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Hofmann
Higher Education Commission of Pakistan, 44000 Islamabad, Pakistan.
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Hussain
D000818:Animals; D003198:Computer Simulation; D006801:Humans; D019570:Inhalation Exposure / Q000032:analysis*; D008168:Lung / Q000378:metabolism* / Q000528:radiation effects; D008954:Models, Biological; D011829:Radiation Dosage; D011874:Radiometry / Q000379:methods; D017687:Radon Daughters / Q000032:analysis* / Q000493:pharmacokinetics; D051381:Rats; D020318:Rats, Long-Evans; D017207:Rats, Sprague-Dawley; D014018:Tissue Distribution
D017687:Radon Daughters