Estimation of indoor radon concentration and dose evaluation of radon and its progeny in selected dwellings in Duhok city, Kurdistan Region, Iraq

Background : Among the natural radioactive sources, two - thirds of radiation dose received by living tissue is caused by radon and its progeny because it can interact with biological tissue when it is inhaled or ingested. Accordingly, this study planned to measure indoor radon and evaluates its doses in addition to studying metrological parameter to understand the correlation between them. Materials and Methods : This study focused on the indoor radon concentration by two different protocols which are short term and long term. In short term, radon concentration was measured in seven dwellings in Duhok city at the beginning of both winter and summer using RAD7 detector and Airthings Corentium monitor. Then annual effective dose of radon and its decay product to the inhabitance were estimated. In long term protocol, radon concentration was measured continually for one year by fixing Corentoum detector in one building. Results : outcomes showed that the concentration of radon is higher in winter than summer; with range of 1 - 56 Bq m - 3 . The average level of indoor radon concentration in both seasons was 19 ± 6.1 Bq m - 3 . The radon and its progeny average annual effective dose were 0.59 ± 0.17 and 0.23 ± 0.14 mSv y - 1 in winter and 0.37 and 0.15 mSv y - 1 in summer respectively. Conclusion : The results of average indoor radon concentration obtained were considerably less than the action levels prescribed by ICRP. Also, the results indicated that radon concentration negatively correlated with wind speed and positively with outdoor temperature while outdoor humidity effect has almost neglected.