How to Lower Radon Gas Levels

Radon is a radioactive gas that is a byproduct of the breakdown of uranium. It is harmless when it dissipates in outdoor air. When it accumulates in an enclosed space such as a home, however, it can cause health problems. The U.S. surgeon general has said exposure to radon gas is the second-leading cause of lung cancer. Radon gas cannot be seen or smelled and does not cause headaches, nausea or other symptoms Take steps to reduce radon levels in your home.

Step 1

Open ground-floor windows on both sides of the house when possible. This can reduce radon levels by circulating air.

Step 2

Ventilate your home’s crawlspace by installing and keeping open foundation vents.

Step 3

Seal basement floor cracks with polyurethane caulking.

Step 4

Keep drain traps moist by pouring water in floor drains once a month.

Step 5

Obtain a radon test kit. They can be purchased at hardware and home improvement stores. Some state health departments provide them for free. Follow directions carefully to get accurate results. If results reveal 4 to 20 picocuries per liter, follow-up testing should be done over the next 12 months. If results reveal 20 to 100 picocuries per liter, another test should be completed in no more than three months.

Step 6

Hire a qualified professional radon mitigation company if long-term testing (over several months or up to a year) shows radon levels over 4 picocuries per liter. The most common mitigation strategy is subslab depressurization. The method extends pipes from a permeable layer of gravel or drain tiles below the basement floor, up through the house and through the roof.


  • The average cost of radon mitigation in existing homes is $1,200.
  • It is not recommended homeowners try to do radon mitigation work themselves. If it is not done correctly, it can make radon levels worse.

About the Author

Cindy Mikel has been writing about education and family issues for more than 25 years. As a newspaper reporter with a journalism degree and as the mother of two grown children, she shares her knowledge of those important subjects with readers on a regular basis. She is also a published photographer.