Waukesha County Environmental Health is a Radon Information Center (RIC) providing guidance on radon testing and mitigation for Waukesha, Racine, and Milwaukee Counties.  Radon is a naturally occurring, odorless, and colorless gas that causes lung cancer.  The only way to know the radon level in a house is to measure it through testing.  Test kits can be purchased through Environmental Health online, in person at our office, or over the phone.

Radon is a cancer-causing, radioactive gas that you can’t see, smell, or taste. As naturally occurring radioactive materials break down in the soil, radon gas is emitted as a by-product and can collect in the basement or lower level rooms of your house.

Because the amount of radon gas being released from the soil varies from house to house, the most economical method of determining if radon gas is present is to conduct a radon test.

Testing for radon is easy and should take only a few minutes of your time. The amount of radon in the air is measured in picocuries per liter. The two types of radon testing kits most commonly used are the short-term charcoal canister and the alpha track kit.

• The short-term charcoal canister can be exposed to air for several days then sent to a testing laboratory for analysis. This charcoal canister is good for determining the radon level and can be used to quickly identify homes with very high radon levels. Since radon levels can very from day to day, the charcoal canister is recommended only as a screening test.
• The alpha track radon test kit is the most common type of kit used for long-term testing. It can be exposed to air for 90 days or more. Because radon levels within the home can vary from day to day, testing over an extended period of time will provide a test result that is more representative of the radon gas concentrations found within the home.

Radon Screening Test

A first time or screening test to determine if radon is present within the home should be done with a short-term carbon canister kit. Place the radon test kit in the lowest “lived in” portion of the house. The kit instruction sheet will list the duration of the test period and where to mail the kit for analysis. Once you have initial test result, use the Homeowner Testing Flowchart to determine your next steps.

Use a long term test kit when initial screening test results are between 4.0-8.0 pCi/L. The long term test kit is run 91-365 days. 

When Selling a Home

When buying or selling a property or when you need to know the radon results in a short time, use a charcoal canister kit and the following procedure:

• Close all windows and doors on all floors of the house 12 hours before beginning the test and throughout the test period. You can go in and out of the house, but keep it closed up as much as possible during the test.
• Use two short-term radon detector kits exposed at the same time or 2 short-term tests run one after another. Place the radon tests kits in the lowest portion of the house that is used for living purposes. The kit instruction sheet will list the duration of the test period and where to mail the kit for analysis. 

Wisconsin Certified Radon Measurement Contractors

Reducing Radon Exposure

There are several ways to lower levels of radon in the home. Which method you choose will depend on how your home is constructed. To learn about ways to reduce radon levels, call the Southeastern Wisconsin Radon Information Center at 262-896-8300.

Visit the EPA website to download these free EPA pamphlets:

• How to Reduce Radon Levels in Your Home
• Citizen's Guide to Radon

List of Wisconsin Radon Mitigation Contractors

Radon Levels in Wisconsin

Wisconsin radon test results by County and Zip Code

The accompanying table gives the results of 48,000 short-term basement radon measurements in homes in Wisconsin, listed by county and zip code.

These are basement results. However, the U.S. EPA recommends testing the lowest lived-in levels of houses, not normally basements. The EPA guideline is 4 pCi/L for the radon exposures, as determined by year-average main floor measurements, unless the basement is lived-in significantly, more than seven hours per week, for example.

This procedure is based on a study in which one-year follow-up measurements were done on the first floors in houses where basement 2-day screening levels were over 4 pCi/L in a 1987 Wisconsin-U.S.EPA random survey of 1100 houses. The more measurements there are in the table for a given zip code, the more representative this estimating procedure is.

Far more radon measurements than these listed have been made in the state. The data tabulated were obtained from some companies that sell radon detectors, and are not a random survey. None-the-less, the table indicates that elevated radon occurs in most regions of the state. Whether the chance of elevated radon is one percent or twenty percent, the conclusion is the same: every home should be tested.