Unattached fraction of short-lived Rn decay products in indoor and outdoor environments: An improved single-screen method and results
- Universitaet Goettingen (Germany, F.R.)
The unattached fraction fp of potential alpha energy of short-lived Rn decay products was measured under realistic, natural conditions in different dwellings and in the open atmosphere by a single-screen technique. An improved data evaluation method was developed where the measured activities of {sup 218}Po (RaA) and {sup 214}Pb (RaB) were corrected by the screen-attached activities of {sup 214}Bi ({sup 214}Po) (RaC (RaC')). This method is based on the experimental observation that the {sup 214}Bi ({sup 214}Po) unattached activities are negligible under realistic living conditions and that the size distributions of the aerosol-attached activities of all short-lived Rn daughters are identical. In closed rooms without additional aerosol sources, a mean unattached fraction fp of the potential alpha energy of 0.096 was obtained at a mean aerosol particle concentration of 6100 cm-3 and at a mean equilibrium factor F of 0.30. This mean fp value is about three times higher than the value used in the literature for the radiation exposure calculation of the human public. In closed rooms with additional aerosol sources (cigarette smoke, heating systems, aerosols from a burning candle), the aerosol particle concentrations ranged up to 10(6) cm-3 and the attachment rates, X, increased up to 1000 h-1. The fp values sometimes decreased below the detection limit of 0.005, and the F values increased to as high as 0.77. In the ambient atmosphere in the vicinity of Goettingen, a mean unattached fraction fp of 0.02 and a mean aerosol particle concentration of 3.4 x 10(4) cm-3 were measured at 1 m above the ground. The mean equilibrium factor F was determined to be 0.7.A
- OSTI ID:
- 6701520
- Journal Information:
- Health Physics; (USA), Journal Name: Health Physics; (USA) Vol. 58:6; ISSN 0017-9078; ISSN HLTPA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Surface deposition of 222Rn decay products with and without enhanced air motion
Use of iodine vapor to measure airway deposition of unattached
Related Subjects
540130* -- Environment
Atmospheric-- Radioactive Materials Monitoring & Transport-- (1990-)
AEROSOLS
AIR POLLUTION
ALPHA DECAY RADIOISOTOPES
ALPHA PARTICLES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BISMUTH 214
BISMUTH ISOTOPES
BUILDINGS
CHARGED PARTICLES
COLLOIDS
DAUGHTER PRODUCTS
DISPERSIONS
ECOLOGICAL CONCENTRATION
EVEN-EVEN NUCLEI
HEAVY NUCLEI
HOUSES
INDOOR AIR POLLUTION
ISOTOPES
LEAD 214
LEAD ISOTOPES
MINUTES LIVING RADIOISOTOPES
MONITORING
NUCLEI
ODD-ODD NUCLEI
PARTICLE SIZE
POLLUTION
POLONIUM 218
POLONIUM ISOTOPES
RADIATION MONITORING
RADIOACTIVE AEROSOLS
RADIOECOLOGICAL CONCENTRATION
RADIOISOTOPES
RESIDENTIAL BUILDINGS
SIZE
SOLS