Radon Radon is a naturally occurring radioactive element that can be found in soil, underground water, and outdoor air. Some of the properties of this gas include being odorless, tasteless, and colorless. The concentrations vary throughout the country depending on the types of rocks that are found in the soil. Exposure over prolonged periods of time to radon decay products has been associated with an increased risk of lung cancer.(3) The EPA describes an elevated concentration as being at or above their suggested guidelines of 4pCi/l (pico Curies per liter, used as a radiation unit of measure for radon). Exposures below this level may create a risk of lung cancer, farther reductions to