Evaluation of indoor radon levels in Staff offices of Umm Al Qura University, Saudi Arabia

Radiation is a natural part of the environment that people interact continuously, and radon is one of the most important sources because of its abundance and mobility. Due to gas form, radon can reach and accumulate in living places easily. Inhalation of radon and its progenies is an important risk factor for health hazards. Accurate measurement of radon levels is quite essential for the dose evaluation of radon exposure in buildings. In this present work, radon concentration was measured indoor 30 office in the College of applied Sciences/Umm Al-Qura University. Radon was measured with a portable Radon counter (Rad 7 detector, Durridge-USA), which was placed on the middle of office at a height of about 0.8 m. 222Rn gas levels were registered in Bq/m3.
The measured concentration of radon in the air of office ranged from 14.2 ± 5.68 Bq/m3 to 23.9 ±7.52 Bq/m3 with a mean of 18.96 ± 8.3 Bq/m3, while that of the progeny of radon varied from 0.00164 to 0.00266 WLM Y-1 (average: 0.00211). The mean indoor concentration of radon was considerably less than the lower levels prescribed by EEC 400 Bq/m3, ICRP 200–600 Bq/m3, NRPB 200 Bq/m3, EPA 148 Bq/m3, and WHO 100 Bq/m3. The mean annual effective dose calculated 0.012 mSv y−1, which is less than the UNSCEAR and WHO recommended global lower average dose value of 1 mSv/y. The hazard indices (PAEC, and CPPP) values were lower than the permissibility limit value.