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Study on Pennsylvania Radon Occurrence in Groundwater and Potential Radon Exposure Published

by Margaret Henderson

The United States Geological Survey (USGS), in cooperation with the Pennsylvania Department of Health and Pennsylvania Department of Environmental Protection (DEP), has conducted a study and release findings in a May 2017 report. Results of 1041 groundwater samples from 16 geologic units were used to identify units where high media radon concentrations were present. Samples were collected between 1986-2015.

The study examined the potential radon exposures related to the specific geologic units. The study notes some limitations based on indoor air radon data’s spatial accuracy due to geocoding, and some interpretation accuracy. Usefulness of the study is in promoting awareness regarding potential exposures and identifying data gaps. Information is not intended to predict concentrations or guide decisions about whether or not to test for radon.

Within the study area, six cities with populations in excess of 30,000 were included.
Variations in concentrations of radon in groundwater and indoor air among geologic units were examined using graphical plots and statistical tests.

Test results revealed that in 87% of the samples, concentrations exceed the USEPA maximum contaminant level of 300 pCi/L in groundwater for public water supplies. The DEP has a fact sheet with guidance on radon in water to guide consumers. See http://www.dep.pa.gov/Business/RadiationProtection/RadonDivision/Monitoring/Documents/2940-FS-DEP4429.pdf?Mobile=1&Source=%2FBusiness%2FRadiationProtection%2FRadonDivision%2FMonitoring%2F_layouts%2Fmobile%2Fview.aspx%3FList%3Dcb5aebcd%252Db987%252D4340%252Db03d%252D6a90245e74e4%26View%3Deac22357%252D15ad%252D462e%252Dba6d%252Df27028b165d7%26CurrentPage%3D1

Reference for the study:
Gross, E.L., 2017, Evaluation of radon occurrence in groundwater from 16 geologic units in Pennsylvania, 1986–2015, with application to potential radon exposure from groundwater and indoor air: U.S. Geological Survey Scientific Investigations Report 2017–5018, 24 p., https://doi.org/10.3133/sir20175018.
ISSN: 2328-0328 (online)

For more information about radon in Pennsylvania, contact the Radon Division of the DEP:
Radon Hotline: 800-237-2366