Orphan radon daughters at Denver Radium site
- Bureau of Mines, Denver, CO (United States)
During 18 mo of sampling airborne radioactively at a National Priority List ({open_quotes}Superfund{close_quotes}) site in metroPOlitan Denver, Bureau of mines personnel discovered radon daughters that are not supported by the parent radon gas. We refer to them as {open_quotes}orphan{close_quotes} daughters because the parent, radon, is not present in sufficient concentration to support the measured daughter products. Measurements of the {open_quotes}orphan{close_quotes} daughters were made continuously, using the Bureau-developed radon and working-level (radon-daughter) monitors. The data showed high equilibrium ratios, ranging from 0.7 to 3.5, for long periods of time. Repeated, high-volume, 15-min grab samples were made, using the modified Tsivoglou method, to measure radon daughters, to which thoron daughters contributed 26 {+-} 12%. On average 28 {+-} 6% of the particulate activity was contributed by thoron daughters. Most samples were mixtures in which the {sup 218}Po concentration was lower than that of {sup 214}Pb and {sup 214}Bi, in agreement with the high-equilibrium factors obtained from the continuous sampling data. In view of the short half-life of radon progeny, we conclude that the source of the orphan daughters is not far from the Superfund sites. The mechanism of this phenomenon is not understood at this time, but we will discuss its possible significance in evaluating population doses.
- OSTI ID:
- 45174
- Report Number(s):
- CONF-901010-Pt.1; TRN: 95:003574-0025
- Resource Relation:
- Conference: 29. Hanford symposium on health and the environment: indoor radon and lung cancer--reality or myth, Richland, WA (United States), 15-19 Oct 1990; Other Information: PBD: 1992; Related Information: Is Part Of Indoor radon and lung cancer: Reality or Myth? Part 1; Cross, F.T. [ed.]; PB: 527 p.
- Country of Publication:
- United States
- Language:
- English
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