The microdosimetry of radon and its daughter products in the human respiratory tract
Based on a review of the literature, a model of the human respiratory tract was developed to determined the spatial distribution of alpha source activity in the lung. Factors affecting deposition, retention and clearance of radon daughters were considered. Both basal and secretory cell nuclei were selected as target sites for lung cancer induced by alpha radiation from radon daughters. The source-target geometry was represented by alpha track-length distributions. Using the source-target geometry information obtained, microdosimetric calculations were completed for each airway generation, and specific energy distributions were obtained for a 30 year and a 30 day exposure. Results showed that most target cell nuclei are missed by alpha particles even for an exposure as long as 30 years. Secretory cell nuclei have about twice the probability of being hit compared to basal cell nuclei. Most target cell nuclei are hit only once. The lobar and segmental bronchi have the highest fraction of cells hit; these are also the airways reported to have highest incidence of lung cancer induction. The risk of lung cancer induction, therefore, depends on the probability of target cell nuclei being hit by alpha particles.
- Research Organization:
- Texas A and M Univ., College Station, TX (USA)
- OSTI ID:
- 6694008
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
LUNGS
RADIONUCLIDE KINETICS
NEOPLASMS
RADIOINDUCTION
RADON
DOSIMETRY
ALPHA PARTICLES
CELL NUCLEI
DAUGHTER PRODUCTS
LUNG CLEARANCE
RADIATION DOSES
RISK ASSESSMENT
SPATIAL DISTRIBUTION
BODY
CELL CONSTITUENTS
CHARGED PARTICLES
CLEARANCE
DISEASES
DISTRIBUTION
DOSES
ELEMENTS
EXCRETION
FLUIDS
GASES
ISOTOPES
NONMETALS
ORGANS
RARE GASES
RESPIRATORY SYSTEM
560161* - Radionuclide Effects
Kinetics
& Toxicology- Man