Abstract
Indoor radon and thoron concentration measurements have been intensively carried out since the 1980s for assessment of radiation doses to workers and the general public. For example, the European Union countries established reference levels for indoor radon concentration in relation to national action plans to address long-term risk from radon exposures. Measurements done using a reliable method are the only way to investigate radon concentration levels. In order to ensure the quality of measurements, intercomparisons among laboratories are performed, as one verification method. The primary purpose of this paper is to provide a concise review of intercomparisons of radon and thoron monitors carried out by four institutions: NIRS (Japan), PHE (UK), BfS (Germany) and SURO (Czech Republic). The different measurement set-ups, evaluation methods and statistical treatments utilized by those institutions are described.
