Radium and Radon Exhalation Studies in Some Soil Samples from Singa and Rabak Towns, Sudan using CR-39

Measurements of radium concentration and radon exhalation rates (surface and mass exhalation rates) were made for a number of 120 soil samples from Singa and Rabak towns in Sudan. In this study we used the can technique, containing CR-39, to estimate the radium concentration and radon exhalation rates from the soils of the studied areas. The average radium concentrations from soil samples were found to be (82 8) Bq. kg-1 to (34 3) Bq. kg-1 for Singa and Rabak towns respectively. The radon concentration, surface and mass exhalation rates were found to be (19.9 2.0) kBq. m-3, (17.6 1.8) Bq. m-2. h-1, (354 36) mBq. kg-1. h-1 for Singa town, and (8.2 0.8) kBq. m-3, (7.2 0.7) mBq. m-2. h-1, (145 15) mBq. kg-1. h-1 for Rabak town. From this study we found that, there was a linear relationship between the indoor radon concentration and the radium concentration in the soil. All the values of radium content in soil samples of study areas were found to be lower than the permissible value of 370 Bqkg-1 recommended by Organization for Economic Cooperation and Development.