Radon is released from the earth due to the breakdown of Uranium over millions of years. The radioactive gases created are released from the ground into the atmosphere and can become trapped in the home. Elevated levels of radon trapped in the home are the leading cause of lung cancer among non-smokers. Colorado is known to have high-levels of radon throughout the state and 3 out of 4 homes have higher than the 4.0 pCi/L action level set by the EPA.