Review of Radon Equilibrium Factors

["Strom, Daniel J" <daniel.j.strom@pnl.gov>]

The U.S. Department of Energy sponsored at least one recent review of
radon equilibrium factors in various settings.  This review appears in
Appendix A, pp. 124-127, of SAFT-0057, Proposed Standard for Internal
Dosimetry.  This draft standard is available in its entirety at

http://www.doe.gov/html/techstds/tsdrafts/saft0057.pdf

16 studies of equilibrium factors outdoors near ground level showed a
range of 0.01 to 1.00, with an average of 0.39 and a standard deviation
of 0.25.  In general, reports do not give the uncertainties on
equilibrium factor measurements.  Clearly, the distance from the source
of radon (e.g., a tailings pile) is critical: if one is close to the
source, the equilibrium factor is lower than if one is farther from the
source.

- Dan Strom

The opinions expressed above are my own, and have not been reviewed or
approved by Battelle, the Pacific Northwest National Laboratory, or the
U.S. Department of Energy.

Daniel J. Strom, Ph.D., CHP
Risk Analysis and Health Protection, K3-56, Pacific Northwest National
Laboratory
Battelle Boulevard, P.O. Box 999, Richland, WA 99352-0999 USA
(509) 375-2626 fax: (509) 375-2019 daniel.j.strom@pnl.gov