Indoor air radon

摘要

Radon is a colourless, odourless naturally occurring inert radioactive gas (in the series from the periodic table of helium, neon, argon, krypton, xenon and radon). There are 27 known isotopes of radon of which three occur naturally; viz., ~219Rn, ~220Rn and ~222Rn. The latter is the longest lived (half life of 3.8 days) and is commonly called radon (Cothern and Smith, 1987). Radon occurs naturally and contributes about half of the background radiation to which we are all exposed (Cothern and Lappenbusch, 1986).