Radon in your home: What to know and how to stay safe

The air in your quiet Midwest home may seem safe, but it could carry a hidden risk from radon, a gas with no color, smell or taste.

Radon is especially problematic in our region due to soil conditions and the way homes are constructed. The average radon level in Minnesota is more than three times the national average, and about two in five homes test high for radon. In Wisconsin, about one in 10 homes tests high.

Fortunately, affordable testing is widely available, and radon mitigation systems can be installed in homes with high levels.

What is radon?

Radon is a naturally occurring, radioactive gas produced by the breakdown of uranium in soil, rock and groundwater. As radon decays, it releases radiation that can damage lung tissue.

All outdoor air contains small amounts of radon, but it becomes more concentrated indoors. Air pressure inside a house is often lower than the pressure in the surrounding soil. This causes radon to be pulled into the home through:

• cracks in floors and walls
• sump pits
• floor drains
• gaps around pipes

Radon and lung cancer

Public health agencies estimate that radon contributes to about 21,000 lung cancer deaths in the U.S. each year. This makes radon the leading cause of lung cancer for non-smokers and the second leading cause overall. If you smoke and your home has high radon levels, your risk is especially high.

Radon and children

Children breathe faster than adults and spend more time near the floor, where radon levels can be higher. Homes with children, child-care settings and schools can all benefit from routine radon testing and fixes when needed.

How to measure your home’s radon level

The only way to know your home’s radon level is to test it. The EPA recommends testing:

• if your home’s radon level is unknown
• when buying or selling a home
• before and after renovations, including mitigation work
• after creating a new living space, such as a basement bedroom

The Minnesota Department of Health recommends retesting every two to five years.

Measuring radon levels

Radon is measured in picocuries per liter (pCi/L). The Environmental Protection Agency (EPA) recommends installing a mitigation system if levels are 4 pCi/L or higher. Even levels below 4 pCi/L carry some risk and, in many cases, can be reduced with professional mitigation.

Tests for measuring radon in homes

There are two main types of home radon tests:

• Short-term tests typically measure radon levels for two to seven days. They are the quickest way to screen for radon and are usually where you should start.
• Long-term tests measure radon for at least 90 days and provide the best estimate of your home’s yearly average. Testing should include both heating and non-heating seasons.

The Minnesota Department of Health recommends completing two tests before deciding how to fix a radon problem, unless a professional uses a continuous monitor during a real estate transaction.

Contact the health department in Minnesota or Wisconsin for more information about test kits and where to purchase them. Test kits are also available online and in home improvement stores.

Fixing high levels of radon in a home

Lowering radon in a home is called radon mitigation. The goal of these systems is to reduce radon levels to as low as reasonably achievable, below the EPA action level of 4 pCi/L. A quality mitigation system may reduce year-round levels to below 2 pCi/L.

The type of home foundation helps determine which radon mitigation system works best. Most systems use a fan to pull air from the soil and vent it outside above the roofline. A licensed radon mitigation professional can help you determine which type of mitigation system will work best in your home.