Radon Risk Map of Estonia has been produced to provide an overview of the concentration of the radioactive inert gas radon-222 in soil air and of the concentrations of uranium, thorium and potassium in the soil. The aim of the map is to serve as a tool in the effort to reduce the health risk posed by radon in dwellings and workplaces. The Radon Risk Map gives general information on areas where the risk for indoor radon merits attention at planning of new buildings for dwellings and workplaces. The map can also be used to aid in the search for existing buildings, in which the indoor radon concentrations may exceed the permissible limit. The map presented is preliminary; as research proceeds, the new results need to be incorporated. In this way the current areas of radon risk will be more precisely delineated.
The Radon Risk Map is based on existing geologic knowledge as well as results from field surveys conducted in 2002 and 2003. During the surveys, measurements of the radon concentration in soil air and gamma-ray spectrometric measurements were performed at 566 sites. Thesesites were chosen so to achievea representative sampling throughout Estonia.