Measurements of radon, thoron and their progeny concentrations using twin cup dosimeter for indoor Al-Madaancity – Baghdad – Iraq

Abstract

In this study, the activity concentrations of indoor radon, thoron and their progeny have been measured in air for 61 different locations of Al-Maddan city using twin cup dosimeter. Furthermore, some useful parameters concerning the health hazards have been estimated; working level month (WLM), annual effective dose (Eff), and excess lung cancer per million person per year (ELC).The results show that the values of radon gas levels in the investigated districts varied from 56.28 to 194.43Bq/m3with an overall average value 132.96Bq/m3, while 0.313 to 1.085 for WLM with an overall average 0.740, respectively. The value of Eff and ELC have been found to vary from 1.420 to 4.918 mSv/y with an overall average value 3.354mSv/y, and 852 to 2951 with an overall average value 2013, respectively. For thoron gas only, the results showed that the thoron activity concentration varied from 15.05 to 172.40 Bq/m3 with an overall average 76.48 Bq/m3, and 0.021to 0.240for WLM with an overall average 0.106, respectively. The values of Eff and ELC have been found to vary from 0.256 to 2.94 mSv/y with an overall average1.30 mSv/y and from 57 to 652 with an overall average of 298, respectively. The concentration of radon progeny varied from 59.44 to 301.39 Bq/m3 with an overall average 157.62 Bq/m3. The results illustrated that there is a large variation in the values of the measured concentrations. This is due to the wide variation in the construction of the houses in Al-Madaan city. However, all investigated locations have radon concentration below the action level (200-300Bq/m3)that recommended byICRP. Therefore, there is no health hazard of radon in the region of Al-Madaan city where measurements have been performed.