Factors affecting indoor radon concentrations in Greece

Indoor radon concentrations were determined with the use of track-etched detectors and two monitors,both for radon and one for the decay products, in various regions of Greece. Until now, 1137 dwellings have been measured. Some factors, that influence the radon concentration in dwellings, are discussed in this paper. The factors, used in this analysis, were derived from the householders answers to the relevant questions about various physical features of the dwelling. Different statistical methods were used, as the unpaired t-test and the ANOVA method. The ANOVA method was used on the set of 945 dwellings with complete radon measurements and questionnaires. The factors, which have been studied are the height of the dwelling from the ground, the position of the detector in the room, the building materials, as well as the type of the building, the floor, the basement, the construction period, the contact with other buildings and the mechanical ventilation. It was found that only the height of the dwelling and the building materials affect radon concentrations. The soil was not included as a factor, due to lack of soil data for the total number of 945 dwellings. Only, in a subgroup of 120 dwellings in selected areas in Greece, we checked any possible correlation between indoor radon concentration and radium content of the substrate soil, butthe linear correlation coefficient was very low.