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Summertime short-term negative radon tests need to be retested in winter.
James L McNees1, Susan H Roberts
1Office of Radiation Control, Alabama Department of Public Health, P. O. Box 303017, Montgomery, AL 36130-3017, USA. jmcnees@adph.state.al.us
Health Physics
|June 15, 2007
Summary
Summer radon tests below the U.S. EPA action level may not reliably indicate a home
Area of Science:
- Environmental Health
- Public Health
- Indoor Air Quality
Background:
- Radon testing is crucial for identifying homes requiring mitigation.
- Summer radon tests below the U.S. Environmental Protection Agency (U.S. EPA) action level may not accurately reflect year-round radon concentrations.
Purpose of the Study:
- To evaluate the reliability of short-term summer radon tests in predicting the need for radon removal systems.
- To determine if low summer radon readings are indicative of safe winter radon levels.
Main Methods:
- Utilized a database of past Alabama Radon Program tests.
- Offered free wintertime radon retesting kits to homeowners with previous low summer readings.
- Analyzed 186 valid wintertime retests conducted statewide.
Main Results:
- 27% of statewide winter retests exceeded the U.S. EPA action level of 1.48x10(2) Bq m-3.
- In high-incidence areas, 41% of winter retests were at or above the action level.
- A one-in-three chance exists for a home with low summer radon to exceed the action level in winter in high-risk Alabama areas.
Conclusions:
- Short-term summer radon tests below the U.S. EPA action level are not a reliable indicator of a home's overall radon risk.
- Wintertime radon retesting is recommended, especially in known high-radon areas, even after low summer test results.
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