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Radon Fact Sheet

What Is Known About This Topic?
Radon is less of a problem outdoors. This is because it is diluted to low levels in the outdoor air. However, radon can accumulate to high levels in indoor air. The amount of radon indoors depends on the amount of radon in the underlying soil. Radon gas can enter a home from the soil through cracks in concrete floors, utility services access points, spaces around floor drains, sump pump, construction joints and tiny cracks in basement walls.

Radon levels are generally highest in basements and ground floor rooms that are in contact with the soil. Any home may have a radon problem. It can include new and old homes, well sealed and drafty homes, and homes with or without a basement.

Radon may also be released into indoor air from well water during showering and other household activities. However, compared to airborne radon, waterborne radon poses less of a risk in most cases.

How Does Radon Harm the Body?
Prolonged exposure to high radon levels is a health concern. This is because radon gas decays into solid radioactive particles that can be trapped in the lungs when you breather. As the solid particles undergo further radioactive decay, the particles release small bursts of energy that can damage lung tissue and lead to lung cancer over the course of a lifetime. The amount of time between radon exposure and the onset of lung cancer may be many years. If you smoke and your home has a high radon level your risk of developing lung cancer is greater.

What Can I Do To Prevent The Problem?
It is relatively inexpensive and easy to determine if radon is a problem in your home. All you need to do is test for radon. There are both short-term "do it yourself" radon tests kits that are available by mail order and in many retial stores. Common short-term devices include charcoal canisters and alpha track detectors. These short term tests typically remain in the home from 2-7 days. Long term tests remain in the home for up to one year. Alpha track detectors are commonly used for long term testing. Whatever testing method you choose, make sure that the kit is state certified. If you don't want to test for radon yourself, a trained state certified contractor can perform the testing.

What Do the Test Results Mean?
The amount of radon in the air is measured in "picocuries per liter of air (pCi/L)" The Environmental Protection Agency (EPA) has set a yearly average home radon level of 4 pCi/L as an "action level" (a level to take reduction steps).

Although no radon level is considered "safe", the risk of developing lung cancer is directly related to the concentration and duration of exposure to radon: the higher the radon level, the higher the lung cancer risk. However studies performed at the University of Iowa and elsewhere, have shown that prolonged exposure to radon, even below the EPA's action level, increases a person's risk of developing lung cancer.

How Can Radon Levels Be Reduced in Homes?
There are a variety of methods used to reduce radon in the home. All involve one of two things. First is keeping radon from leaking into the house. Second is ventilating radon to the outdoors.

Some methods might include sealing cracks in floors and walls. Another is drawing soil gas away from the house before it enters. While homeowners can implement some corrective measures, radon reduction generally requires the skills of a professional radon contractor. The cost to correct radon problems can range from about $800-2,500, with the average cost being about $1,300. The EPA's "Consumer's Guide to Radon Reduction" discusses radon reduction techniques in more depth. If your employer has a "Health Care Spending Account, radon reduction costs are often an eligible expense.

Where Can I Get More Information?

University of Iowa Resources

• University of Iowa College of Public Health, Department of Epidemiology
• Cancer Information Service (1-800-237-1225)

Other Resources

• Iowa Department of Public Health Radon Information Line (800-383-5992)
• National Safety Council Radon Information Line (800-SOS-RADON)
• United States Environmental Protection Agency

If you would like more information on radon and cancer or telephone numbers to the above organizations, please contact the Cancer Information Service at 1-800-237-1225 or e-mail: cancer-information@uiowa.edu.

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