A study of radon and thoron release from Egyptian building materials usingpolymeric 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 t rack detectors. The free areal exhalation rate was measured by the sealed c up-technique, whereas the radium content was obtained by the alpha-autoradi ographic method. The calibration coefficient for thoron measurements in air using cylindrical cup equipped with LR-115 detector was estimated. Moreove r, the calibration coefficients for measurements of the specific activities of Ra-224 and 226Ra were also evaluated. New method was developed for eval uating the emanation coefficient as well as the diffusion coefficient of ra don isotopes in the studied materials. (C) 2001 Elsevier Science Ltd. All r ights reserved.