“…During the last few decades, radon physics has been extended to the use of radon as a tool for uranium or radium exploration in mines and building materials, in addition to soil and water (Miles, 1992;Clarke, 1995;Maged and Borham, 1997;Dixon, 1999;Howarth and Miles, 2000;Al-Jarallah, 2001;Mustapha et al, 2002;Surinder et al, 2002). Thus, in our previous work (Saad et al, 2003), we introduced a new method for determining the uranium content of phosphate ores by using a passive radon dosimeter based on CR-39 nuclear track detector (NTD) on-line with an Alpha GUARD radon gas analyzer.…”