This study attempts to draw a map of radon gas vulnerability for Ghana and to ascertain the variation in its levels over the years around Lake Bosomtwi, in the Ashanti Region of Ghana. Radon gas is a radioactive, colourless, odourless and tasteless gas. The study compared the gas levels to those from previous years. The average level was 130.94 pCi/L, which is considered to be greatly above levels suitable for residential purposes. The Western, Central, Greater Accra and Ashanti Regions have had surveys for radon gas but there is no information on the levels of the gas in the other regions.