A Study on Radon in Dwellings

Abstract
Values of the radon and radon daughter concentration in different types of Norwegian dwellings are reported. The mean radon concentrations found were 1.3 pCi/l., 2.0 pCi/l. and 1.0 pCi/l. for buildings with outer walls of wood, concrete and brick, respectively. An equilibrium factor of 0.5 was found to be representative for the dwellings. The variations of the radon concentration due to ventilation and atmospheric pressure were investigated by continuous measurements with an ionization chamber inside a room with very poor ventilation and a room with strong artificial ventilation. A daily decrease of 1 mmHg was found to give an increase in the radon concentration of about 6% of the mean value. The population average dose to the bronchial epithelium from inhalation of radon's short-lived daughters was found to be about 220 mrad/yr in Norway.