Home > Patients & Visitors > Health Library > Radon
Radon is a radioactive gas that causes cancer. Radon is found in rock, soil, water, some building materials, and natural gas. You can't see, taste, or smell it.
Any home, school, office, or other building can have high levels of radon. Radon is found in new and old buildings. It can seep in through any opening where the building contacts the soil. If a house's water supply contains radon, radon may enter the air inside the house through pipes, drains, faucets, or appliances that use water. Then the radon may get trapped inside the house.
Studies show that nearly 1 out of 15 homes in the United States has unsafe levels of radon.footnote 1 If you live in an area that has large deposits of uranium, you may be more likely to be exposed to high levels of radon. (To see a map of the U.S. radon zones, see the website www.epa.gov/radon/zonemap.html.) But the construction features and exact location of your house may be just as likely to affect your risk. Even houses right next to each other can have very different radon levels.
Over time, exposure to radon can cause lung cancer. Radon causes about 21,000 lung cancer deaths each year in the U.S. It is the second leading cause of lung cancer, after tobacco smoking.footnote 1 People who smoke have an even higher risk of lung cancer from radon exposure than people who don't smoke.
Radon exposure doesn't cause symptoms. Unless your home or office is tested for high radon levels, you may not realize that you are being exposed to dangerous levels of radon until you or someone in your family is diagnosed with lung cancer.
The U.S. Surgeon General and the U.S. Environmental Protection Agency (EPA) recommend that all homes be tested for radon levels.
You can hire a qualified tester to do the test, or you can use a do-it-yourself test kit. Use only home tests that are labeled "meets EPA requirements." You can buy radon test kits by calling the EPA at 1-800-SOS-RADON (1-800-767-7236). There are two types of tests. Both measure radon levels in the air.
The EPA recommends placing the test kit in your home on the lowest level that you regularly use. If you have questions about radon in your house, you can get help from the EPA by calling 1-800-55-RADON (1-800-557-2366).
If tests find a high level of radon, you'll need to reduce it. There are two parts to this:
Use an EPA-qualified contractor with proper training in radon reduction to help with this work.
After radon reduction or prevention procedures are done, the home or building should be retested. You may need to retest more than once. It is usually safe to live in the home or building while the radon is being vented, but you may want to confirm this with your local EPA office.
For general information about removing or reducing radon in your house, you can call the Radon Fix-It Hotline at 1-800-644-6999. If you live outside the U.S., you can call your regional environmental protection office for more information.
U.S. Environmental Protection Agency (2012). A Citizen's Guide to Radon: The Guide to Protecting Yourself and Your Family From Radon. Available online:http://www.epa.gov/radon/pubs/citguide.html.
U.S. Environmental Protection Agency (2010). Consumer's Guide to Radon Reduction. Available online: http://www.epa.gov/radon/pdfs/consguid.pdf.
Current as of:
August 21, 2019
Author: Healthwise StaffMedical Review: Anne C. Poinier MD - Internal MedicineE. Gregory Thompson MD - Internal MedicineKathleen Romito MD - Family MedicineAdam Husney MD - Family MedicineR. Steven Tharratt MD, MPVM, FACP, FCCP - Pulmonology, Critical Care Medicine, Medical Toxicology
Current as of: August 21, 2019
Author: Healthwise Staff
Medical Review:Anne C. Poinier MD - Internal Medicine & E. Gregory Thompson MD - Internal Medicine & Kathleen Romito MD - Family Medicine & Adam Husney MD - Family Medicine & R. Steven Tharratt MD, MPVM, FACP, FCCP - Pulmonology, Critical Care Medicine, Medical Toxicology
To learn more about Healthwise, visit Healthwise.org.
© 1995-2020 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.
Our interactive Decision Points guide you through making key health decisions by combining medical information with your personal information.
You'll find Decision Points to help you answer questions about:
Get started learning more about your health!
Our Interactive Tools can help you make smart decisions for a healthier life. You'll find personal calculators and tools for health and fitness, lifestyle checkups and pregnancy.
Feeling under the weather?
Use our interactive symptom checker to evaluate your symptoms and determine appropriate action or treatment.