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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). 

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.

Can the same person test and mitigate a home?

Only if that person is the resident. If the person provides measurement or mitigation services, the answer is "No." 32 Illinois Administrative Code 422 prohibits licensed measurement and mitigation at the same address by the same practitioner.

Is it a conflict of interest to use the same company for testing and mitigation?

Yes, Illinois Administrative code 422 prohibits licensed measurement and mitigation at the same address.

Where can I get more information?

IEMA Division of Nuclear Safety


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