The effects of indoor gamma dose rate, permeability of soil, substructure, and ventilation on indoor radon concentration

The effect of indoor gamma dose rate, permeability of soil, substructure, and ventilation habits of inhabitants were studied using data of 84 low rise residential houses collected in an area of enhanced indoor radon concentration. The radon concentrations varied from 30 to more than 5000 Bqm-3. Cross-tabulation, comparisons of means and multiplicative models were used to test the significance of the effects. In this study a quite high percentage of explained variation R2 - 68% - was found. It was found that the most important factors were the substructure and the permeability of the soil. Because of the rather small size and moderate variation in the uranium content of the bedrock of the area, the effect of the indoor gamma dose rate was not so prominent. The effects of
ventilation habits and sleeping with open windows were not detected in this study.