Radon is an “inert” radioactive gas – it can react with fluorine, with a half life of 3.82 days. With this long half life, you tend to exhale what you breathe in, but the decay products produce most of the radiation dose and the subsequent lung cancers.
Because radon is invisible, little attention is given to it. In Australia, a survey of 3,300 homes gave an average level of 11 Bq m-3. This compares to a global average indoor value of 40 Bq m-3 .
The data can also be viewed in Google Earth. ARPANSA recommends that an annual average radon concentration of 200 Bq m-3 be used as the Action Level for simple remedial action. Less than 0.1% of Australian homes exceed this Action Level.
With the massive increase in gas drilling in Queensland, it will be interesting to see whether there are any radon/ radon progeny related issues, particularly on the impellers of gas pumping stations, in dewatering plants and LNG gasification units.
