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Uninvited guest in our homes: Radon

Freeport, Ill. - With the cool fall weather upon us, our thoughts turn to closing up the house tight for the winter. Most of us do a fall cleaning to collect up the last of that summer pollen and dust, check the batteries in the smoke alarms and carbon monoxide detectors, and make sure windows and doors are sealed tight. With these tasks complete, we can breathe easy for the winter. Or can we?

Radon, the leading cause of lung cancer among non-smokers, could also be trapped in your home, according to Jay Solomon, Energy and Environmental Stewardship Educator with University of Illinois Extension. The only way to know if your home has elevated radon levels is to test it. Once you know you have an issue, installation of a mitigation system is usually fairly straightforward and not cost prohibitive.

According to the American Cancer Society, lung cancer has the highest mortality rates among cancers. Radon is the leading cause of lung cancer in non-smokers and the second leading cause of lung cancer in the United States.

An estimated 1,160 people develop radon-related lung cancer each year in Illinois, according to the Illinois Emergency Management Agency. Extended exposure to elevated indoor concentrations of radon gas in our homes is a major culprit. Elevated radon concentrations have been found in homes in every county in the state. Professional radon measurers have found over 41% of Illinois homes tested at or above the recommended action level of 4 picocuries per liter of air.

Radon is a soil gas formed by the breakdown of naturally occurring uranium in the soil. This colorless, odorless, radioactive gas finds its way into homes through cracks and openings in floors and subsurface walls. While basements are frequently associated with elevated radon levels, crawl-spaces and slab-on-grade homes can also have high levels due to the same upward movement of radon through and out of the soil.

The only way to know if you have an elevated radon concentration in your home is to TEST. Homeowner test kits are available at most hardware and home improvement stores, other major retailers, and many county health departments. Most of these kits are for short term evaluation, with exposure (test duration) times of 2 to 7 days.

Testing for radon is as easy as following a few simple instructions included with the test kit you purchase. The kit should be placed in areas that would be considered a living space: living rooms, den, game room, bedroom, etc. The goal is to test the air you breathe, Place or hang the kit a minimum of several inches above the floor or below the ceiling. A rough rule of thumb, place the test kit at normal breathing height (sitting or standing).

The US Environmental Protection Agency recommends keeping indoor radon concentration below 4.0 picocuries per liter of air. For houses with elevated radon levels, mitigation systems can be installed to reduce concentrations. These systems are usually fairly quick to install at reasonable cost.

A mitigation system intercepts radon between the soil surface and your home, Solomon continued. It safely vents the captured gas into the atmosphere above your home. The system is very simple in principle.

The only way to know the radon level in your home is to conduct a test of the home. The magnitude of the radon issue in Illinois becomes more apparent as more homes are evaluated. Inform yourself and test your home.

For more information about radon, visit or call your local University of Illinois Extension. For a list of Measurement and Mitigation professionals, visit the IEMA web site:


Jay Solomon is an Energy and Environmental Stewardship Educator with the University of Illinois Extension. Solomon provides leadership in environmental and energy programs in northwest Illinois for landowners, homeowners and residents. His areas of focus include: energy conservation, development of alternative energy sources, and enhancement and protection of natural resources.