Influence of climate, building and residential factors on radon levels in ground-floor dwellings in Montenegro

After year-long measurements with CR-39 detectors, nationwide radon survey was performed in 953 homes - 0.5% of all permanently inhabited dwellings in Montenegro. Influence of 11 factors (area, climate, type of house, year of construction, basement, foundation slab, number of stories, building materials, window frames, heating and smoking) and 35 their categories on the radon concentrations in 732 ground-floor dwellings was analyzed using descriptive, univariate and multivariate methods. Univariate analysis dropped influence of the two factors - heating and smoking. It reveals that, on average, radon concentrations in ground-floor dwellings differ at 95% confidence level in urban and rural areas, in family houses and apartment buildings, in houses with and without basement, and in dwellings with window frames made of wood and PVC/Al. In Cf climate zone they differ from those in Cs and Df zones. Only two pairs of construction periods differ in mean radon concentrations in dwellings: 1980-1999 with 1900-1944, and with 1964-1979. Houses with one, two or three stories have almost equal average radon levels, which are higher than in buildings with more than three stories. Mean value of radon concentrations in houses made of stone are higher than in houses made of concrete, or bricks, or wood. Multivariate analysis revealed that six of the analyzed factors - area, climate, type of house, presence of basement, number of stories and building materials simultaneously have significant relationships (p < 0.05) with radon concentrations in dwellings on ground floor in Montenegro.