Indoor radon survey in Finland: methodology and applications

The methods and equipment used in the indoor radon survey being carried out by the Finnish Centre for Radiation and Nuclear Safety (STUK) are presented. The track densities of mailed alpha track dosemeters are determined by an automatic track counting device coupled to a personal computer. Data concerning the house are compiled using a questionnaire. The 2-month mean concentrations are converted to annual mean using a seasonal adjustment programme. A mapping system loaded into a PC is used to read geographical coordinates from local maps and the type of bedrock and soil from geological maps. STUK's indoor radon information system is used to research and plan mitigation and preventative activities, to present results as thematic maps and to study the radon significance. (author)