Radon Fact Sheet

Radon is a tasteless, colorless and odorless gas that is a decay product of uranium and occurs naturally in soil and rock. Radon gas has been identified as the second leading cause of lung cancer, second only to cigarette smoking, and it is estimated to be responsible for 21,000 deaths from lung cancer annually.¹  This number includes smokers whose risk for cancer is increased by radon exposure. Radon breaks down into components called radon progeny, sometimes called "radon daughters," which emit high-energy alpha particles. These emissions raise the risk of lung cancer.

• The main source of high-level radon pollution in buildings is surrounding uranium-containing soil such as granite, shale, phosphate and pitchblende. Radon enters a home through cracks in walls, basement floors, foundations and other openings. It may also contaminate the water supply, especially in private wells.²
• A level of 4 picocuries per liter (pCi/L) of air has been identified by the U.S. Environmental Protection Agency as an annual average for homes and schools at which remedial action should be taken.³
• It has been estimated that approximately one third of radon-induced lung cancer could be avoided if homes with radon concentrations exceeding the EPA action level underwent changes to reduce radon concentrations to below that level. However, eliminating all radon exposure is not possible.⁴
• Elevated levels of radon have been identified in every state. An estimated 8 million homes in the United States are estimated to have elevated levels of radon.⁵
• It is estimated that between 10% and 14% of lung cancer deaths in the United States could be attributed to radon. Most of the radon-related lung cancers occur among smokers. However, an estimated 2,900 of the 21,000 deaths from lung cancer among nonsmokers in the United States each year are estimated to be radon-related.⁶
• The World Health Organization (WHO) estimates that radon causes between 6% and 15% of lung cancers worldwide.⁷
• It is possible for one home to have elevated levels of radon while a neighboring home does not. Testing is the only way to determine levels of radon in a structure. Testing can be done through do-it-yourself home test kits or through a professional testing firm.
• Home test kits labeled "meets EPA requirements" should be used. Both long-term and short-term tests can be done.
• Short-term tests remain in the home for two to 90 days, depending on the device. "Charcoal canisters," "alpha track," "electret ion chamber," "continuous monitors," and "charcoal liquid scintillation" detectors are the most common short-term testing devices.
• Long-term tests remain in the home for more than 90 days. “Alpha track” and “electret” detectors are commonly used for this type of testing. A long-term test gives a more accurate annual average radon level than a short-term test, because radon levels vary day to day and season to season.
• Radon levels can be lowered through a variety of repairs, from sealing cracks in floors and walls to changing the flow of air into the building.
• Sub-slab depressurization uses pipes and fans to remove radon gas from beneath the concrete floor and foundation before it can enter the building. Radon is vented above the roof, where it safely disperses.
• Repairs to decrease radon levels should be made by an EPA or state-certified contractor.⁸
• For more information call the American Lung Association at 1-800-LUNG-USA (1-800-586-4872), or visit our web site at http://www.lungusa.org.