To understand Radon and it’s health effects it is imperative to have a basic understanding of the chemistry behind the element. Radon Gas is a by-product of the radioactive decay of Thorium and Uranium (used in Nuclear reactors). Over billions of years, the decay processes of Thorium and Uranium produce Radium which immediately forms Radon Gas.
Unlike it’s parent elements, Radon (Rn-222) has a short half-life of 3.8 days. As the gas undergoes it’s own radioactive decay process it transforms into short-lived atoms known as radon daughters which are actually isotopes of Polonium, Lead, and Bismuth. During each successive decay, radioactive alpha and beta particles are emitted and it is these particles that are most harmful.