Radon is a colorless, odorless, tasteless radioactive gas caused by the decay of other radioactive substances. It can enter homes through cracks in the basement and foundation walls. In large enough amounts and concentrations, it is believed to be carcinogenic.
Radon is measured in picocuries (a measure of radiation) per liter of air (pCi/L). Outdoor levels average .4 pCi/L. The EPA has not established a threshold safe level of radon exposure, but suggests an “action” level of 4 pCi/L.
Radon levels can be tested in one of two ways, passively or continuously. Passive devices such as alpha track detectors and charcoal cannisters yield results in about ten days. Continuous monitors usually require electrical power and trained technician, but have the advantage of immediate results. For the purposes of a real estate transact ion, the EPA provides for a 48-hour procedure that can predict whether a home will have an annual average above 4 pCi/L with 94% accuracy.
Radon exposure is mitigated by removing it before it enters a house. A fan installed in a pipe running from the basement to the attic draws radon up and out of the home.
The Illinois Radon Awareness Act requires Sellers to provide Buyers a Disclosure of Information on Radon Hazards and the pamphlet Radon Testing Guidelines for Real Estate Transactions. The disclosure must be provided before the Buyers are obligated by contract to purchase residential real property. It must be signed and dated by the parties and the Sellers’ agent.