Originally posted 12/2011

Radon map - MO Counties

See U.S. interactive map

Did you know that high levels of radon, a naturally occurring gas that we breathe every day, is the 2nd leading cause of lung cancer?

Did you know that it is easy to find out if the radon rate in your home is dangerous?

Did you know that it is easy to fix elevated radon levels in your home?

For years, real estate agents have recommending testing radon levels before buyers purchase a new home. The good news is that radon is easy to test and fix.

Compared to other problems you might discover in your home, the cost is fairly reasonable if you do find a problem and need to have a radon mitigation system installed.

For under $200, you can have your home professionally tested to know if you have a problem that needs to be addressed. If you do have elevated levels of radon in your home, you can have it mitigated, eliminating dangerous radon gas levels, for around $700 (extremely large homes will be a little more expensive).

There are also DIY test kits available for a lot less money. I wouldn’t use these during a real estate transaction, as there would be no way of knowing if the home seller carried it outside during the test to reduce the radon level for the results. But, it is a good inexpensive solution to testing your home for yourself.

What are the Radon Levels in St. Louis?

Missouri is identified by the EPA as having moderate risk. This means that there is good chance that any given home will have radon levels in their home that is higher than 4.0 pCi/L, the level established by the EPA as putting your health at risk.

NOTE: The World Health Organization sets the acceptable level of radon at 2.7 pCi/L.

St. Louis Home Radon Levels

Radon Level (pCi/L)
% of Homes above
4.0 pCi/L

% of Homes above
2.0 pCi/L

Missouri Counties: 
St. Louis City 2.5 17.8% 48.2%
St. Louis County 4.0 28.8% 56.6%
St. Charles County 4.0 27.5% 54.5%
Jefferson County 5.3 37.0% 67.3%
Franklin County 3.4 32.8% 60.2%
Warren County 4.1 35.1% 61.4%
Lincoln County 4.0 33.0% 60.8%
Illinois Counties:
Madison County 4.0 34.5% 64.3%
St. Clair County 4.5 40.4% 67.2%
Monroe County 4.9 39.8% 67.5%

What does this mean?

If you live in St. Louis County, almost 1 in 3 homes has radon levels that are above the level the E.P.A. defines as safe.

Your risk of living in a home with high radon levels is lowest in St. Louis City, and highest in Jefferson County, MO or the Illinois counties of St. Clair or Monroe.

Does this mean that St. Louis City homeowners don’t need to test their homes?

Absolutely not.

While your chances of having a home with a radon issue is lower, if you happen to live in the 1 in 5 home that DOES have a dangerous radon level, you are putting yourself and your family at risk for lung cancer even if you do not smoke. If you are a smoker or former smoker, your risk for getting lung cancer is even higher.

People who live in rental homes or ground level condos should also have their homes tested.

Dr. Oz has a video that does a great job of explaining what radon is, how it gets into your home, and how it can cause lung cancer. Pop over to watch the video and then give me a call if you want me to connect you with an inspector to test for radon.

If you do find high levels of radon in your house, contact me so I can get you a Realtor discount through a local radon mitigation company.