A Comparison Study of Radon exhalation Rate from Fresh and Destroyed Building Materials in Jabalia-Gaza, Palestine

Abstract

This study aims at assessing the contribution of fresh and destroyed building materials in war 2014 towards the total indoor radon exposure to the inhabitants of Jabalia district in Gaza. 40 Samples have been collected from common destroyed building materials in 2014 war in Jabalia district, and another similar 40 samples from fresh building material from Gaza. The closed-can technique has been employed in this study using solid state nuclear track detectors (CR-39). After 124 days of exposure to radon, CR-39 detectors were etched chemically by (6N) NaOH solution at 75o C for 4.20 hours and then counted under an optical microscope. Results show the average radon exhalation rate in term of area from the fresh building materials in the studied samples ranged from (27.27) mBq.m-2.h-1 for glass samples to (107.48) mBq.m-2.h-1 for Asbestos samples, while the destroyed materials ranged from (86.51) mBq.m-2.h-1 for glass samples to (463.90) mBq.m-2.h-1 for Asbestos samples.  On the basis of these values the annual effective dose for each sample was also determined and compared with the effective dose limit values recommended by the National Council on Radiation Protection and  Measurements (from 1 to 5 mSv/y). In general, the annual effective doses from the investigated destroyed building materials are low and under the global value except for Concrete and asbestos of destroyed samples with average values(9.464) and (9.3528) mSv/y, respectively, and from samples of fresh building materials the effective dose are (2.25) for Concrete and (2.71) for Asbestos. There are big differences between results from fresh materials and destroyed materials, which may influenced by war pollution.