Radon 1 © | Radon Testing Services in TN. Radon is an invisible, odorless gas that is the 2nd leading cause of Lung Cancer in the U.S. and kills an estimated 21,000 people every year. This gas is emitted from natural decaying uranium in the soil and it seeps up from the ground into homes. Unfortunately Tennessee is a hotbed for Radon gas, particularly Nashville, Williamson County, Knoxville, and Chattanooga. Since Radon is odorless and invisible, testing for Radon is the only way to know if your home or building is affected. The U.S. Office of the Surgeon General and U.S. If you’re living in Tennessee and your home or building has never been tested for radon gas we STRONGLY reccomend that you do so.