Radon is an odorless, colorless, tasteless, radioactive gas. Radon comes from the decay of radioactive uranium that can be found in small amounts in rocks and soil throughout nature. In areas with disturbed earth, and loose fill, like when a home is built, radon escapes from the soil.
Generally, the air inside a home is lower pressure than the air outside, and combined with the warmer air rising inside, up to 20 percent of the air inside a house can come from the basement. When soil gas and air from fill enter the basement, it may include radon, which is then trapped inside house.
Radon gas continues to radioactively decay once inside the house, producing polonium, bismuth, and lead, which are also radioactive. As these radioactive elements transform, radioactive alpha and beta particles are released, and when inhaled and in contact with living lung tissue, can lead to cancer.
Radon gas exposure is the number one cause of cancer for non-smokers, even greater than second-hand smoke. Most people are exposed to radon gas inside their own homes, and this is their greatest exposure to natural ionizing radiation.
Any home can have a radon problem, the only way to know is to test. Some new homes are built with radon resistant construction techniques, it is still a good idea to plan a radon test to ensure the radon concentration is below the EPA action level. It is easy to add a professional radon test to your home inspections when buying a house.