Faculty, Staff, and Affiliated Publications--KGS


We combined 71,930 short-term (median duration 4 days) home radon test results with 1:24,000-scale bedrock geologic map coverage of Kentucky to produce a statewide geologically based indoor-radon potential map. The test results were positively skewed with a mean of 266 Bq/m3, median of 122 Bq/m3, and 75th percentile of 289 Bq/m3. We identified 106 formations with ≥10 test results. Analysis of results from 20 predominantly monolithologic formations showed indoor-radon concentrations to be positively skewed on a formation-by-formation basis, with a proportional relationship between sample means and standard deviations. Limestone (median 170 Bq/m3) and dolostone (median 130 Bq/m3) tended to have higher indoor-radon concentrations than siltstones and sandstones (median 67 Bq/m3) or unlithified surficial deposits (median 63 Bq/m3). Individual shales had median values ranging from 67 to 189 Bq/m3; the median value for all shale values was 85 Bq/m3. Percentages of values falling above the U.S. Environmental Protection Agency (EPA) action level of 148 Bq/m3 were sandstone and siltstone: 24%, unlithified clastic: 21%, dolostone: 46%, limestone: 55%, and shale: 34%. Mississippian limestones, Ordovician limestones, and Devonian black shales had the highest indoor-radon potential values in Kentucky. Indoor-radon test mean values for the selected formations were also weakly, but statistically significantly, correlated with mean aeroradiometric uranium concentrations. To produce a map useful to nonspecialists, we classified each of the 106 formations into five radon-geologic classes on the basis of their 75th percentile radon concentrations. The statewide map is freely available through an interactive internet map service.

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Funding Information

This project was supported in part by UK-CARES through Grant P30 ES026529, the Kentucky Department for Public Health Radon Program, and the Kentucky Geological Survey (a state-supported research center at the University of Kentucky).

Related Content

The digital geology coverage used in this paper is publicly available through the Kentucky Geological Survey website (http://kgs.uky.edu). The radon test result data set is not publicly available because of a confidentiality agreement with the radon testing labs but is available from the BREATHE program within the University of Kentucky College of Nursing (http://www.uky.edu/breathe) upon reasonable request.

gh2198-sup-0001-2020gh000263-s1.docx (44 kB)
Supporting Information S1

gh2198-sup-0002-2020gh000263-ts01.xlsx (23 kB)
Table S1