How to Test Your Home for Radon

When it comes to reducing your cancer risk, one important step could be right under your nose, or your feet. Getting your home tested for radon can help protect you and your family from a key cause of lung cancer.

Exposure to radon accounts for about 21,000 deaths from lung cancer each year according to the US Environmental Protection Agency (EPA). While that is nowhere near the 480,000 deaths a year caused by smoking, it’s still significant. And it’s the leading cause of lung cancer in people who don't smoke.

What is radon?

Radon is a gas that occurs naturally outdoors in harmless amounts. It’s produced from the breakdown of uranium in soil and rocks. It sometimes gets concentrated in homes built on soil with natural uranium deposits. It can enter buildings through cracks in floors or walls, construction joints, or gaps in foundations around pipes, wires or pumps. Radon levels are usually highest in the basement or crawl space.

When someone breathes in radon gas, it goes into their lungs, exposing them to small amounts of radiation. This may damage the cells in the lining of the lungs and increase a person's risk of lung cancer. The risk is higher in those who have lived for many years in a radon-contaminated house.

Exposure to the combination of radon gas and cigarette smoke creates a greater risk for lung cancer than either factor alone.

Testing for radon

Because radon gas can’t be seen or smelled, the only way to know whether you're being exposed to it is to test for it. A Citizen’s Guide to Radon, produced by the EPA, explains how to test your home for radon easily and inexpensively, and what to do if your levels are too high.

You can hire a professional tester or do it yourself with a kit you buy at a hardware store or online. Follow the instructions for leaving the kit in your house for the required number of days. Then mail it to a lab and wait for the results.

If radon levels in your home are high, you can take steps to lower them. The most common method is to have a vent pipe system and fan installed, which pulls radon from beneath the house and vents it to the outside.

It is also possible for radon to enter your home through your water supply, though this poses a much lower risk than when it comes through the soil. If you have a private well, you can have it tested for radon. If the levels are high, you can have the water supply treated so that the radon is removed before it enters your home. If you are concerned about radon and your water comes from a public water supply, you should contact your supplier.

As with most home repairs, the cost of reducing radon in your home can vary widely, depending on how your home is built (whether you have a basement, crawlspace, or neither) and what kind of system you need.

If you think you’ve been exposed

There are no widely available medical tests to measure whether you have been exposed to radon. But if you think that you might have been, talk with your doctor about whether you should get regular health checkups and tests to look for possible signs of lung cancer. Possible symptoms include shortness of breath (difficulty breathing), a new or worsening cough, pain or tightness in the chest, hoarseness, or trouble swallowing.

If you smoke and you know you’ve been exposed to high levels of radon, it’s very important to quit smoking. The combination of cigarette smoking and radon exposure raises the risk of lung cancer more than either smoking or radon exposure alone.

For some people exposed to radon through their jobs, like uranium miners, millers and transporters, the US government has established the Radiation Exposure Compensation Program. It offers compensation for lung cancer and some other lung diseases to people who qualify.

Reviewed by
Helpful resources

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as editors and translators with extensive experience in medical writing.

  • 1-800-SOS-RADON Purchase radon test kits
  • 1-800-55RADON Live help for your radon questions
  • 1-800-644-6999 Info about reducing radon in your home
  • 1-866-528-3187 Obtener ayuda en vivo con sus preguntas
  • 1-800-426-4791 Info on safe drinking water and radon in water