Recently, radon sources have been a matter of concern, as high levels
have been measured in some houses. This work contributes to the assess
ment of radon exhalation from those stones which are mostly used for b
uilding materials, The first part of this paper concerns measurements
of natural radionuclide concentrations (U-238, Th-232) in building mat
erials by means of gamma-spectrometry, The second part deals with the
determination of stone exhalation rate using a particular instrument,
called an 'emanometer', designed and developed at our institute. As a
general result, this research indicates that the radon exhalation is d
etermined more by the peculiar characteristics of the building materia
l than by its specific content of radium. Copyright (C) 1996 Elsevier
Science Limited