A fast and accurate method for measuring radon exhalation rates from building materials.

: Building materials commonly used in the U.S. were surveyed for both radionuclide content and radon emanation rate. Particular emphasis was placed on concrete, for which samples from ten major metropolitan areas were measured. Gamma-ray spectroscopy techniques, as well as direct radon emanation measurements, were employed in this study. The results of this survey suggest that these materials are not the primary source of radon in typical U.S. houses.