Radon is an odorless radioactive gas that results from the breakdown of uranium. Uranium is present in most of the soil and rock around the world. It is typically concentrated in areas with lots of granite, shale, phosphate and pitchblende. The major source of high levels of radon in homes is soils around the house that may contain uranium, granite, shale phosphate and pitchblende. Because radon is a gas, it can enter a home or building through dirt floors, shale-block walls, cracks in the foundation floor and walls, and openings around floor drains, pipes and sump pumps.
Radon is often more highly concentrated in basements, ground floors and first floor homes.
Radon problems have been identified in every state even in the state of Georgia. The publication illustrates each of the 3,141 counties in the United States assigned to one of three zones. Look at the picture of the State of Georgia on the left . The darkened areas include Cobb and surrounding counties. This area is designated as zone 1.