We are very strongly urging our home inspection clients to have a radon test performed before making a final decision about whether to purchase a home. Radon is a naturally occurring radioactive gas that can be dangerous when it builds up inside of confined spaces. It is estimated that 20,000 people die each year due to exposure to radon, and it is the number one cause of lung cancer among non-smokers (number two overall). 25% of homes within Chicago and 40% of those in the suburbs that have been tested have come back with results showing radon levels above EPA safety guidelines. Due to the relatively small number of homes that currently get tested, the percentage of homes with dangerous levels of radon could actually be much higher.