Radon: The odorless, invisible threat

Radon: The odorless, invisible threat

By
Mayo Clinic Staff

January 30, 2023

Radon is an odorless, invisible radioactive gas. It's naturally released from rocks, soil and water — and it can get trapped inside your home, office or school. There's no known safe level of radon. Unfortunately, there are no symptoms of radon exposure as there are with carbon monoxide poisoning.

What makes radon so dangerous

Breathing high levels over time can lead to lung cancer. In fact, radon is a Class A carcinogen. It's the No. 1 cause of lung cancer in nonsmokers and the second-leading cause of lung cancer overall. Nationwide, 21,000 people die from radon-caused lung cancer each year.

Smoking and secondhand smoke, combined with exposure to high radon levels, increase your risk of lung cancer. If you or your family are experiencing breathing issues, consult with a pulmonologist.

Radon can be found in any home — old or new — and typically enters through cracks in the foundation caused by natural settling and windows. Radon levels often are higher in lower levels and basements. Across the U.S., 1 in 15 homes have elevated radon levels, and levels are higher in the Midwest. For Minnesota homes, the average radon level is about 4.5 picocuries per liter of air (pCi/L) compared to 1.3 pCi/L nationwide.

Test your nest for radon

There's a simple solution to this close-to-home health hazard: Test your nest. That's what the Environmental Protection Agency (EPA) urges all homeowners to do, especially those in high-radon areas. Testing is the only way to determine the radon level in your home.

You can find radon testing kits at hardware or other home maintenance stores. They run about $20 or less, and are easy to use. It typically takes two to seven days for results. Since there's no safe level of radon, you should always aim for the lowest level. The EPA recommends 4 pCi/L or less.

If your home tests higher than 4 pCi/L, then you'll need to have a professional fix the radon issue, which includes installing venting equipment. The equipment looks like a big tube that reaches below the foundation of your home and vents radon up and out of the house. Unfortunately, the system can be expensive, but you may be able to apply for assistance from your state.

Once the mitigation system has been installed, your home should be tested again to make sure the fix is effective. Even if your home passes the first test, you should retest every two years.

Also, radon testing is not required when selling a home. So, as a buyer, you should insist on it. If levels are high, you can negotiate costs with the seller.