A STUDY OF RADON EMITTED FROM BUILDING MATERIALS USING POLYMERIC NUCLEAR TRACK DETECTORS

Radon has been recognized to be one of the major contributors to natural radiation even causing lung cancer if present at enhanced levels. Accurate knowledge of exhalation rate plays an important role in characterization of the radon source strength in some building materials. It is a useful quantity to compare the relative importance of different sample of building materials.

For this purpose, in this study the Can Technique using CR-39 plastic track detectors was used to measure radium content and exhalation rates of radon in building samples collected from Jizan districts-a province in southern Saudi Arabia. The values of effective radium content are found to vary from 0.21 to 2.2 Bq kg-1 with a mean value of 0.92 Bq kg-1 and a standard deviation of 0.81. All the values of radium content in all samples under test were found to be quite lower than the permissible value of 370 Bq kg-1 recommended by Organization for Economic Cooperation and Development. The values of mass exhalation rates of radon vary from 1.6 to 16.7 mBq kg-1 h-1 with a mean value of 6.9 mBq kg-1 h-1, while the surface exhalation rates vary from 29.7 to 998.9 mBq m-2 h-1 with a mean value of 219.6 mBq m-2 h-1. Alpha index and annual effective doses have also been estimated.