This diploma thesis was written during spring term in 2004 by Malin Olsson and Johan Tengström on the initiative of supervisor Göran Nyman, professor at Göteborg University and Chalmers University of Technology.

The aim of the study was to provide a compilation of facts on radon related issues from different countries in Europe and in the USA, and to give an answer to the question what is being done in the different countries to help solving radon related problems?

It was also desirable to create a computerized catalogue containing all compiled information on each country along with a useful search tool. Therefore, this version of the thesis was constructed. This presentation differs from the printable version, which is concentrated on Denmark, Finland, Germany, Norway, Sweden, United Kingdom and the USA. This version contains a few more countries, and provides further information, such as e.g. a listing of international organizations, and scientific publications, that has not been included in the printed version.