title: Year-to-year variations in annual average indoor 222Rn concentrations.
abstract: Annual average indoor 222Rn concentrations in 40 residences in and around Grand Junction, CO, have been measured repeatedly since 1984 using commercial alpha-track monitors (ATM) deployed for successive 12-mo time periods. Data obtained provide a quantitative measure of the year-to-year variations in the annual average Rn concentrations in these structures over this 6-y period. A mean coefficient of variation of 25% was observed for the year-to-year variability of the measurements at 25 sampling stations for which complete data were available. Individual coefficients of variation at the various stations ranged from a low of 7.7% to a high of 51%. The observed mean coefficient of variation includes contributions due to the variability in detector response as well as the true year-to-year variation in the annual average Rn concentrations. Factoring out the contributions from the measured variability in the response of the detectors used, the actual year-to-year variability of the annual average Rn concentrations was approximately 22%.
authors.affiliation: Chem-Nuclear Geotech, Inc., U.S. Department of Energy, Grand Junction, CO 81502.
authors.forename: D E
authors.initials: DE
authors.lastname: Martz
authors.forename: A S
authors.initials: AS
authors.lastname: Rood
authors.forename: J L
authors.initials: JL
authors.lastname: George
authors.forename: M D
authors.initials: MD
authors.lastname: Pearson
authors.forename: G H
authors.initials: GH
authors.lastname: Langner
mesh_terms: D000396:Air Pollutants, Radioactive / Q000032:analysis*; D003120:Colorado; D006798:Housing; D011834:Radiation Monitoring / Q000295:instrumentation; D011886:Radon / Q000032:analysis*; D013997:Time Factors
chemical_list: D000396:Air Pollutants, Radioactive; D011886:Radon