Radioactivity in building materials: room model analysis and experimental methods

First, models Žroom models. published in the international literature allowing the exposure to gamma radiation indoors due to building materials to be assessed are reviewed and discussed. For one of them, a sensitivity analysis concerning the effect of changing the parameters Že.g. dimensions of the room, thickness and density of the walls, etc.. used in calculations is performed. Second, a method is proposed for calculating the activity concentration in the walls of a room using: Ža. the measured absorbed dose rate in air in the room; Žb. the contributions of natural radionuclides Ž238U, 232Th and 40K. to the absorbed dose rate in air assessed by means of gamma spectrometry indoors; and Žc. the specific dose rate ŽnGy h 1 per Bq kg 1. of natural radionuclides, for the chosen room geometry, calculated with the room model.