Measurements of Indoor Radon Levels and Dose Estimation and Lung Cancer Risk Determination for Workers in Health Centres of Some Towns in the Sudan

Abstract

Abstract:The indoor radon concentration level and radon effective dose rate were carried out in the health centers of Khartoum, Behri(Khartoum North), Medani and Kassala towns -Sudan, in 222 measurements, using passive integrated solid-state nuclear track devices containing allyl diglycol carbonate plastic detectors. The radon concentration in the corresponding health centers was found to vary from 60 ± 12 Bq.m -3 , in Kassala town health centers, and 34 ± 9 Bq.m -3 in Wad Medani town health centers, while Khartoum and Behri (Khartoum North) health centers are recording an average values of 49 ± 12 Bq.m -3 to 46 ± 11 Bq.m -3 , respectively. The overall average of radon concentration for health centers in our study was found to be 47 ± 11 Bq.m -3 . These values are noticed to be far below than the radon action level 200-600 Bq.m -3 as recommended by ICRP. Assuming an indoor occupancy factor of 0.8 and 0.4 for the equilibrium factor of radon indoors, we found that the annual effective dose rate from radon was estimated to be 1.19 ± 0.28 mSv.y -1 , and the relative lung cancer risk for radon exposure was found to be 1.042%. From our study, it is clear that the annual effective dose rate is lower than both the "normal" back ground level as quoted by UNSCEAR and the recommended action level of ICRP, and less than the maximum permissible dose defined by the International Atomic Energy Agency.

Radon Monitoring in the Environment

“…The relative risk of lung cancer (RRLC) due to indoor exposure to radon should be calculated by using the following formula [29,52]:…”