A study of radon and thoron release from Egyptian building materials using polymeric nuclear track detectors

The free exhalation rates of both thoron and radon, the specific activities of Ra-224, and Ra-226, and the physical properties, such as the emanation coefficients and radon effective diffusion coefficient of several building material samples were determined using LR-115 and CR-39 polymeric nuclear track detectors. The free areal exhalation rate was measured by the sealed cup-technique, whereas the radium content was obtained by the alpha-autoradiographic method. The calibration coefficient for thoron measurements in air using cylindrical cup equipped with LR-115 detector was estimated. Moreover, the calibration coefficients for measurements of the specific activities of Ra-224 and 226Ra were also evaluated. New method was developed for evaluating the emanation coefficient as well as the diffusion coefficient of radon isotopes in the studied materials. (C) 2001 Elsevier Science Ltd. All rights reserved.