Radon is a colorless, odorless, tasteless, and chemically inert radioactive gas. It is formed by the natural radioactive decay of uranium in rock, soil, and water. Naturally existing, low levels of uranium occur widely in Earth's crust. It can be found in all 50 states. Unless you test for it, there is no way of telling how much is present.
Recent Radon Pooling Studies
Two pooling studies reduce the uncertainty associated with residential risk estimates and add to the body of scientific knowledge which supports action to reduce the public's exposure to radon in indoor air. See the North American pooling abstract and the European pooling abstract.
National Radon Program Services at Kansas State University are funded by the U.S. Environmental Protection Agency under Cooperative Agreement XA-83312602.