The State of Illinois now requires a radon disclosure on all homes.  Radon testing has become increasingly popular among Home Buyers to know the levels within the home.   The level acceptable as per the state is 4.0.  Anything above that advises mitigation that can start at $850 and increase depending on size and foundation.  Radon is a colorless, odorless, tasteless radioactive gas that comes from the radioactive decay of naturally occurring uranium in the soil. It can enter homes and buildings through small cracks in the foundation, sump pumps or soil in crawlspaces.  The Illinois Emergency Management Agency (IEMA) is urging homeowners throughout the state to test their homes for radon after a study of radon testing results found nearly half of 22,000 homes tested by professionals had potentially unsafe levels of radon. The study also found 80 counties where few, if any, professional tests for the naturally occurring radioactive gas known to cause lung cancer were conducted during the two-year study period.For free radon testing kits contact the Champaign Urbana Public Health District at 217-352-7961.