A macroscopic and microscopic study of radon exposure using geant4 and mcnpx to estimate dose rates and dna damage

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Publication Type thesis
School or College College of Engineering
Department Civil & Environmental Engineering
Author van den akker, Mary Evelyn
Title A macroscopic and microscopic study of radon exposure using geant4 and mcnpx to estimate dose rates and dna damage
Date 2015-12
Description Radon is considered the second-leading cause of lung cancer after smoking. Epidemiological studies have been conducted in miner cohorts as well as general populations to estimate the risks associated with high and low dose exposures. There are problems with extrapolating risk estimates to low dose exposures, mainly that the dose-response curve at low doses is not well understood. Calculated dosimetric quantities give average energy depositions in an organ or a whole body, but morphological features of an individual can affect these values. As opposed to human phantom models, Computed Tomography (CT) scans provide unique, patient-specific geometries that are valuable in modeling the radiological effects of the short-lived radon progeny sources. Monte Carlo particle transport code Geant4 was used with the CT scan data to model radon inhalation in the main bronchial bifurcation. The equivalent dose rates are near the lower bounds of estimates found in the literature, depending on source volume. To complement the macroscopic study, simulations were run in a small tissue volume in Geant4-DNA toolkit. As an expansion of Geant4 meant to simulate direct physical interactions at the cellular level, the particle track structure of the radon progeny alphas can be analyzed to estimate the damage that can occur in sensitive cellular structures like the DNA molecule. These estimates of DNA double strand breaks are lower than those found in Geant4-DNA studies. Further refinements of the microscopic model are at the cutting edge of nanodosimetry research.
Type Text
Publisher University of Utah
Subject Dosimetry; Geant4; Radon
Dissertation Institution University of Utah
Dissertation Name Master of Science
Language eng
Rights Management Copyright © Mary Evelyn van den Akker 2015
Format Medium application/pdf
Format Extent 27,423 bytes
Identifier etd3/id/3975
ARK ark:/87278/s6gx7kv2
Setname ir_etd
ID 197525
Reference URL https://collections.lib.utah.edu/ark:/87278/s6gx7kv2