Radon is a naturally occurring Radioactive gas which is derived from the Uranium and Thorium decay series. Radon (Rn-222) is a colourless, odourless, dense and chemically un-reactive substances and is the daughter of radium within the above-described series. It can be found in houses and workplace, more so where the ground contains Uranium decay series bearing rocks (e.g. granite). Radon is considered a health hazard because it decays to solid daughter products with the emission of Alpha Particles. For example, Rn-222 decays with a Half-Life of 3.8 days to Polonium-218, which itself then decays again (with a smaller half-life of 3 minutes) by an alpha particle to Lead-218. The decay series continues until stable Lead-206 is formed.