A critical review of measurements of the unattached'' fraction of the radon decay products
Exposure to radon and its decay products is known to cause lung cancer. It is the deposition of the decay products within the respiratory tract that delivers the dose leading to adverse health effects. An important concept in understanding the health effects of the radon progeny is the unattached'' fraction. It was suggested that there is a highly diffusive form of the radon and thoron decay products that can be fully deposited in the respiratory system referred to as the unattached fraction.'' Initial measurements were made using diffusional deposition in tubes to separate the high diffusivity unattached'' activity from that associated with lower diffusion coefficient particles. Subsequently, wire screens were used to estimate unattached'' Rn daughter fractions in ambient and mine atmospheres. Wire screen penetration theory along with a semi-empirically corrected diffusion coefficient equation can be used to characterize the previously reported unattached'' fraction measurements. Collection efficiency curves have been estimated for previously published wire screen unattached'' fraction measurements and the measurements available in the literature are reviewed and discussed. The purpose for measuring unattached fraction is to estimate the dose to the respiratory tract arising from the deposition of radon decay products to which the individual is exposed. Therefore, if measurements could be made in a manner that better reflected the aerodynamic behavior of the radon progeny in the respiratory tract, then the assessment of exposure could be directly related to dose with far greater accuracy. Respiratory deposition models can serve as basis for such a system and the design concepts of such a measurement system is presented. 104 refs., 34 figs., 7 tabs.
- Research Organization:
- Clarkson Coll. of Tech., Potsdam, NY (USA). Dept. of Chemistry
- Sponsoring Organization:
- DOE/ER
- DOE Contract Number:
- FG02-89ER60876
- OSTI ID:
- 7189645
- Report Number(s):
- DOE/ER-0451P; ON: DE90010157
- Country of Publication:
- United States
- Language:
- English
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Improving the validity of wire screen unattached fraction Rn daughter measurements
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63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AIR POLLUTION
ALPHA DECAY RADIOISOTOPES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CARCINOGENESIS
CHRONIC EXPOSURE
DAUGHTER PRODUCTS
DISEASES
DOSES
ELEMENTS
EQUATIONS
EVEN-EVEN NUCLEI
FLUIDS
GASES
HAZARDS
HEALTH HAZARDS
HEAVY NUCLEI
INDOOR AIR POLLUTION
INHALATION
INTAKE
ISOTOPES
LUNGS
MATHEMATICAL MODELS
MEASURING METHODS
MINUTES LIVING RADIOISOTOPES
NEOPLASMS
NONMETALS
NUCLEI
ORGANS
PATHOGENESIS
POLLUTION
POLONIUM 218
POLONIUM ISOTOPES
RADIATION DOSES
RADIATION HAZARDS
RADIOISOTOPES
RADON
RADON 220
RADON ISOTOPES
RARE GASES
RESPIRATORY SYSTEM
RETENTION
RISK ASSESSMENT
SECONDS LIVING RADIOISOTOPES