Public Health Madison & Dane County

Radon is a colorless, odorless, radioactive gas that is naturally released from rock, water, and soil. It can build up in the lowest levels of a building, like basements, but it can be detected on any level of your home.

Radon can cause lung cancer with long-term exposure. In fact, it’s the leading cause of lung cancer in non-smokers. It’s usually not realistic to completely get rid of radon, but it is fairly simple to lower your home’s radon to a safer level.

If you own a home

• The only way to know if you have radon is to test. Homes both old and new can have dangerous levels of radon.
• You should test for radon every two years. Experts also recommend testing after altering or renovating your home.
• You can get a short-term test kit from a hardware store for less than $20, or from one of our public health offices for $10. There are also radon testing services you can use. If you’re using a short-term test kit, it takes just a couple minutes to set up, and you’ll collect it and mail it in a few days later.

If you’re about to buy a home

• Depending on the offer you make on a home, radon testing may be a part of your home inspection.
• If you do not get an inspection on a home, or radon testing is not included in the inspection, test for radon after you close on the house. Make sure you’re including the cost of a potential radon mitigation system in your budget (usually around $1,200).

• You can get a short-term test kit from a hardware store for less than $20, or from one of our public health offices for $10. There are also radon testing services you can use. If you’re using a short-term test kit, it takes just a couple minutes to set up, and you’ll collect it and mail it in a few days later.

If you rent

• If you live on the third floor or above, you likely don’t have to worry about radon. Because it’s released from soil, you’re likely up too high for radon to be a significant risk for you.
• If you live on the second floor or below, ask your landlord about the last time the unit was tested for radon and what the result was. If you’re shopping around for a new rental, this is a great question to ask ahead of time.
• The lower your unit is to the ground, the more opportunity there is for radon to be in your home. So if you live in a basement unit, it’s most important for you to test.
• If you want to do a test, talk to your landlord beforehand and see if they’d be willing to make the repair if radon was found to be high. Unfortunately, landlords are not required to mitigate radon in Wisconsin.

• You can get a short-term test kit from a hardware store for less than $20, or from one of our public health offices for $10. There are also radon testing services you can use. If you’re using a short-term test kit, it takes just a couple minutes to set up, and you’ll collect it and mail it in a few days later.

Understanding your results

• The best time to test is during winter, when your house is sealed up. Opening windows, like we often do in the summer, can artificially lower test results.
• Depending on your test result, you might need to retest sooner than two years, or you might need to install a radon mitigation system (typically around $1200). Learn more about test results on the Wisconsin Department of Health Services Website. If you need a mitigation system, be sure to use a certified contractor.
• Even if you have a low radon level, you should retest in two years. Test earlier if your home goes through renovations.