Welcome to the Midwest – the land of world-renowned barbeque, abundant crops, exceptional football teams and high levels of radon.
Radon is an odorless, tasteless, and colorless gas. It’s found in the soil and originates by the decomposition of radioactive materials. Radon leaks into cracks and joints in a home’s foundation and is common inside homes throughout Kansas and Missouri. Here is a map that shows radon levels by zip code in Johnson County.
Radon is also the second leading cause of lung cancer, after smoking. (Source: Centers for Disease Control and Prevention “CDC”).

How to test for radon in your home
It’s important to test for radon when you purchase a home. I typically advise having a professional test completed before a buyer’s closing, so they are aware of the active radon levels and any repairs that need to be completed. This test is typically 48 hours and measures the levels of radon inside the home. If the test shows average radon levels above 4 pCi/picocuries per liter, then the United States Environmental Protection Agency (“EPA”) guidance says that repairs should be made to the home by a certified radon service professional to decrease radon levels. There are several radon mitigation service providers in the Johnson County area. They typically install a ventilation system that will push the radon gas from the ground to vent outside the exterior of the home.
However, you shouldn’t wait until you buy your next home. You can test your radon levels now to ensure that your radon levels are below the EPA recommendation of 4.0 pCi/Pico Curies per liter. It’s inexpensive and easy. In fact – you can visit the Johnson County K-State Research and Extension office in Olathe (11811 S. Sunset Drive, Suite 1500, Olathe) and purchase a Do-It-Yourself radon test kit for a mere 15 dollars. More information may be found here.

When to retest radon levels
The EPA recommends that you test the radon levels in your home every two years; regardless of radon levels lower than 4.0 pCi, or you have a radon mitigation system installed. It’s also a good idea to continually test every two years or sooner if you have done any types of remodeling or updates to your home that would affect your home’s foundation.
Additional Resources
- Radon and Your Health
- What is radon gas? Is it dangerous?
- Johnson County K-State Research and Extension office
- International Association of Certified Home Inspectors
Johnson County market update
This week in Johnson County there were 1065 active listings; which was more than a four percent increase from last week. 1516 listings went under contract; which was nearly a six percent increase from last week. (Source: Heartland MLS, May 11, 2023).
About Maggie
Maggie is a ReeceNichols real estate agent and a third-generation realtor. It’s her passion to provide a professional and positive buying and selling experience to her clients. Maggie has been featured in Realtor.com, Apartment Therapy and in other publications. https://maggief.reecenichols.com/
Follow her on Instagram and Facebook for updates on the local market


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