Courtesy of the U.S. Environmental Protection Agency. Radon is an odorless, colorless, tasteless gas formed from the natural breakdown of uranium. The gas is found naturally in certain soils around the United States. It enters buildings through cracks in concrete floors and walls, and especially builds up in basements. Decaying radon produces radioactive particles that can enter the lungs and cause damage, including cancer, over time. The U.S. Environmental Protection Agency (EPA) calls radon the...