The Good News About Radon

What is radon?

Radon is a cancer-causing, radioactive gas that has been found in homes ll over the world. It is the result of decay from uranium and occurs naturally underground in soil, rock, and water. Wisconsin has a relatively elevated level of uranium in the soil that is believed to have been left behind from glaciers receding.

What does the abbreviation of pCi/L really mean?

Radon is measured using picocuries per liter (pCi/L), which is a unit of measure for the amount of radioactivity in a liter of air. The prefix “pico” means a trillionth. A Curie is a commonly used measurement of radioactivity equivalent to 1 gram of radium. Roughly, 0.4 picocuries per liter (pCi/L) of radon is normally found in the outside air.

What causes radon levels to be higher in some homes and not others?

You cannot see, smell or taste radon, but it may seep into homes through cracks in the floors and foundations of homes. The amount of radon that enters a home depends on the weather, soil porosity, soil moisture, and the suction within the house. Therefore, you cannot predict radon levels based on state, local, and neighborhood radon measurements. While the average indoor radon level is estimated to be about 1.3 pCI/L, nearly one out of every 15 homes in the United States is estimated to have an elevated radon level. Testing is the only way to accurately detect if radon is present in a home. Since you cannot see or smell radon, special equipment is needed to detect it.

What is the seller’s role with radon testing?

Testing for radon is not complicated. However, there is a potential for test interference, being intentional or not. It is imperative that the home owners are made aware of their responsibilities for testing. Disturbing or interfering with the test device or with closed-house conditions may invalidate the test results and require another test. Wisconsin Inspection Consultants utilizes devices that are specifically designed to deter and detect test interference.

Testing requires that the home be kept under closed-house conditions; all windows and doors must be kept closed (except for normal entry and exit) and fans or other machines, which can bring air in from outside, should not be operated during this time. Fans that are part of a radon-reduction system or small exhaust fans can be operated for short periods of time during the test. In addition to maintaining closed-house conditions during the measurement, these conditions should be initiated at least 12 hours prior to the testing. Closed-house conditions are necessary for short-term measurements in order to stabilize the radon concentrations.

How is radon detected?

Radon measurement devices fall broadly into two categories: passive or active radon monitors.

  • A passive radon monitor is generally small and light-weight and does not require any power to operate. They also need to be sent to a laboratory for analysis. Examples of these monitors are charcoal canisters, electret ion chambers, and alpha track detectors.
  • Continuous Radon MonitorActive radon testing devices require power to function. These devices can receive power from an outlet or a battery. Active radon testing devices include continuous radon monitors (CRM) and continuous working level monitors. they constantly measure and record the amount of radon or its decay products found in the home.

At WIC, our inspectors use continuous radon monitors. We are aware that time is of the essence in real estate transactions. By having the ability to recognize what the average radon levels are on site, this allows you to move past this contingency sooner and offers you the most time to overcome any potential issues that arise.

What can I do if I have high levels of radon in my home?

The Environmental Protection Agency (EPA) recommends that you take corrective measures to exposures of radon levels equal or greater then 4 pCi/L. They also believe that any radon exposure carries some risk and that no level of radon is safe. The U.S. Surgeon General has warned that radon is the second leading cause of lung cancer in the United States. You can reduce your risk of lung cancer by lowering the radon level in your home and even very high levels can be reduced to acceptable levels.

Sub-Slab Depressurization MeasureA variety of methods can be used to reduce radon levels in homes. Sealing cracks and other openings in the foundation is only part of radon reduction. Sealing alone has not been shown to lower radon levels significantly or consistently. In most cases, a system with a vent pipe and fan is used to reduce radon. These “sub-slab depressurization” systems do not require major changes to your home. Similar systems can also be installed in homes with crawl spaces.

Looking for a mitigation contractor?

A local radon mitigation contractor is Radon Solutions. You can reach them by email at, or by phone at (608) 235-3886. For a list of additional radon mitigation contractors, you may visit the Wisconsin Department of Health Services Radon Mitigation Contractor List.

There are no state regulations specifically for radon mitigation businesses in Wisconsin. The attached list is combined from two national certifying organizations.

Do you have any further questions?

Now that you are aware of the serious health risks of radon exposure, you can breathe easy knowing that it is very simple to detect and even a house with high levels of radon can be reduced to acceptable levels. Feel free to email us with any questions at, or call our office at (608) 222-8848.

For more information on radon, please visit the EPA’s Radon site.