Common Questions and Answers about Radon

What is radon?

Radon is a colorless, odorless, tasteless, radioactive gas produced during the natural decay of uranium (an element that occurs in small amounts in rock and soil). As it decays, radon releases radioactive particles and energy into the air. Radon that decays while in the lungs can cause cell damage and potentially lead to lung cancer. Therefore, elevated levels of radon in a building or home can negatively affect the occupant’s health.

Where does radon come from?

Radon is found naturally in the soil and rock composing the earth’s crust. In Illinois, central and northern regions have been shown to have higher levels of radon in soil. Radon gas migrates through the ground before entering the atmosphere where it mixes with outside air or becomes concentrated inside buildings.

What health effects are associated with radon?

When radon and radon decay products are inhaled, they can cause damage to the cells and tissues of the lungs, which can lead to lung cancer over the course of a lifetime. Not everyone who is exposed to radon will get lung cancer. The time between exposure and cancer diagnosis may be many years.

The U.S. Environmental Protection Agency (USEPA) estimates that approximately 21,000 deaths each year are attributable to radon-induced lung cancer. The U.S. Surgeon General has warned that radon gas is the second leading cause of lung cancer in the United States (second only to smoking), and first among non-smokers. Individuals who smoke and are exposed to high levels of radon are especially vulnerable.

How can I be exposed to radon?

As radon travels through the soil, it can easily move through small spaces in a foundation and enter a building. This includes, but is not limited to, floor drains, sump pits, crawl spaces, foundation cracks and gaps around pipes and wires. The foundation makes no difference – radon has been measured in buildings with varying foundation styles. Since radon enters a building through the ground, lower levels such as basements, tend to have higher measured levels. According to a study conducted by the Illinois Emergency Management Agency (IEMA), 41 percent of homes tested for radon in Illinois had levels higher than the action level of 4.0 picoCuries per liter (pCi/L).

How do I test for radon?

The only way to determine the level of radon in your home is to have the air tested. Low cost, “do-it-yourself” test kits can be purchased from hardware stores, and also may be available from local health departments. The IEMA Radon Program and the Illinois Department of Public Health recommend that levels in homes be less than 4.0 pCi/L. If levels exceed this number, radon mitigation should be used to reduce the levels and decrease the risk of lung cancer. The USEPA recommends you test your home for radon every two years.

See for more detailed information about radon measurements in the home.

Does the Illinois Department of Public Health test for radon?

No, the Department does not conduct radon testing. Individuals can check radon levels at home using a kit or through the services of a qualified radon mitigator.

Are there licensed professionals that perform radon mitigation?

Under the Radon Industry Licensing Act, IEMA licenses radon measurement and mitigation professionals in Illinois. A list of professionals can be found at The most common radon reduction system involves the installation of a vent pipe and fan system, which draws air from underneath a building and displaces it outside. The cost of a system varies depending on the reduction method chosen and building size, usually ranging between $800 and $1,200.

Does Illinois have laws that pertain to radon?

Existing legislation includes the Illinois Radon Awareness Act and the Illinois Real Property Disclosure Act. Both require that upon the purchase of a home or other residential property, the buyer be informed about indoor radon exposure. In addition, if a property has been tested for radon, the results must be disclosed to the buyer. However, this legislation does not require property be tested, or mitigation be conducted if tests indicate high levels of radon.

As well, recent additions to the Child Care Act of 1969 (225 ILCS 10), Section 5.8, concerns the regulation of radon testing in licensed daycare centers, daycare homes, and group daycare homes. The section requires licensed daycare centers, daycare homes, and group daycare homes to test for radon at least once every three years and that all new applications or renewals for a daycare center, daycare home, or group daycare home license must require proof of radon testing within the last three years according to the rules established by IEMA. Section 5.8 also states that facilities must post their current radon measurement next to the Department issued license, and copies must be provided to parents or guardians upon request.

Where can I get more information?

Illinois Department of Public Health
Division of Environmental Health
525 West Jefferson Street
Springfield, Illinois 62761
TTY (hearing impaired use only) 800-547-0466

IEMA Division of Nuclear Safety





idph online home
Environmental Health Home

Illinois Department of Public Health
535 West Jefferson Street
Springfield, Illinois 62761
Phone 217-782-4977
Fax 217-782-3987
TTY 800-547-0466
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