Radon in dwellings: The importance of ventilation

Summary

People who live in industrial countries receive a radioactive dose of 2.4 mSv/y: the most important contribution to this dose is given by radon decay products. Radon is a noble gas generated from the disintegration of radium, which is found in soils and building materials. Owing to a bad air circulation, radon and its daughters may accumulate in a house. By using a mathematical model it may be shown that radon concentration is inversely proportional to the ventilation rate. Measurements of radon concentration through the method of activated carbon canisters, show that in a room with a double-pane window, kept continuously closed, the mean radon concentration can exceed the concentration of a similar room with a single-pane window of 190%. However, the radon concentration inside the energy-saving room may be decreased up to values slightly higher than those measured in the conventional window room, by simply opening the double-pane window a few minutes a day. A set of measurements carried out in a group of house in Reggio Emilia validates the effectiveness of that practice: radon concentrations in rooms with double-pane window closely approximated to those of rooms with ordinary window.