Radon in the air. More about the Watras home. Radon compared to other radiation sources.
Radon is a colorless, odorless gas, a radioactive byproduct of radium.
It is part of the natural radioactive decay series starting with uranium-238. It is radioactive with a half-life of 3.8 days, decaying by the emission of alpha particles to polonium, bismuth, and lead in successive steps. The decay of radon-222 with emission of an alpha particle is followed within about an hour by a series of four further decays, two of them accompanied by emission of alpha particles and the other two accompanied by other types of radiation. The short-lived atoms into which a radon atom decays are actually isotopes of polonium, lead, and bismuth, but they are referred to collectively as radon daughters, or, by those sensitive to questions of gender, as radon progeny. The radon daughter atoms float around in the air during their few minutes of existence, often becoming attached to dust particles.