Seasonal changeability of indoor radon concentrations in one-family house

Indoor radon concentration undergoes 24-hour and seasonal changes. The paper presents first in Poland results of radon concentration changeability in one building during the whole year. We performed 103 measurements of indoor radon concentrations. The following parameters of radon concentration distribution were obtained: arithmetic mean - 224.1 Bq m 3, geometric mean - 194.5 Bq m 3, median - 207 Bq m 3, and geometric standard deviation - 1.84. The minimum observed value was 22 Bq m 3 and the maximum - 748 Bq m 3. We determined the monthly and annual values of radon concentrations. The values for particular months are in the range of 0.5 to 1.6 of the annual mean. We observed a correlation between the mean radon concentrations in the examined buildings and the differences in the mean values of indoor (R = 0.91, p < 0.05) and outdoor temperatures (R = 0.91, p < 0.05). There was also a connection between the radon concentration inside the buildings and the changes in atmospheric pressure.