Monday, December 13, 2010
ROCHESTER, Minn. — Radon is thought to be the second-leading cause of lung cancer after smoking — responsible for an estimated 21,000 deaths annually in the United States.
The December issue of Mayo Clinic Women's HealthSource covers how this invisible gas seeps into homes, the dangers it presents, the importance of home testing, and what to do when radon levels are high.
Radon can't be seen, tasted or smelled but it can be found in soil everywhere. Radon is produced from the natural breakdown of uranium in the earth. Radon in the ground moves upward into the air, entering homes and buildings through foundation cracks, construction joints or gaps around pipes.
Radon exposes lung cells to small bursts of radiation that damage the DNA of sensitive cells lining the airways, setting the stage for lung cancer to develop. If it develops, lung cancer will typically appear five to 25 years after radon exposure. Smokers exposed to radon face a much higher risk of lung cancer than nonsmokers with the same radon exposure.
Nearly one out of 15 homes in the United States is thought to have elevated levels of radon. Levels may vary depending on the amount of uranium in the soil and the home's construction. In general, higher levels are found in the upper Midwest and the northeastern United States. Radon levels may vary within a neighborhood as well as change from day to day and season to season.
Simple tests to measure radon in homes are available from hardware and home improvement stores, many state and local government agencies and some academic centers. Short- and long-term tests are available. A short-term test measures radon levels in the home from two to 90 days, depending on the test kit. The general recommendation is to start with a short-term kit and confirm high results with a second test.
The average indoor radon level, measured in units called picocuries, is about 1.3 picocuries per liter of air (pCi/L). When test results are 4 pCi/L or higher, home modifications are needed to reduce the radon levels. The Environmental Protection Agency (EPA) recommends working with a state-certified or qualified radon mitigation contractor. While costs vary, the average price for radon reduction assistance is about $1,200.
More information and test kit options are available on the EPA website.
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