Radon is a naturally occurring, invisible, odorless gas that comes from deposits of uranium in soil, rock and water. It is harmlessly dispersed in outdoor air but, when trapped in buildings, can be harmful, especially at elevated levels.
Elevated levels of radon have been found in homes in every state.
Radon concentrations can vary greatly from one location to another, even between neighboring homes, because of localized soil composition, construction materials, ventilation and other contributing environmental factors. Any home can have a radon problem, regardless of whether it is old or new, drafty or insulated, with or without a basement.