NATURAL RADIOACTIVITY DUE TO RADON IN DWELLINGS OF KARBALA CITY, IRAQ

In the present work a set of indoor radon levels were measured carried out in different dwellings in Karbala city of Karbala governorate in middle of Iraq. Radon concentrations were determined by using time-integrated passive radon dosimeters( closed and open)containing (CR-39) solid state nuclear track detectors. Measurements were carried out during the three months (November and December of 2015 and Januaryof 2016). The results show that, the radon concentrations varied from(32.21-139.01)Bq/m3 with an average value (62.07)Bq/m3, and(36.70-243.97)Bq/m3 with an average value(93.36)Bq/m3 for closed and open dosimeters respectively, which are less than the lower limit of recommended range (200-300 Bq/m3) (ICRP, 2009). . The values of the indoor annual effective dose vary from(0.02-2.76)mSv/y with an average value(0.68)mSv/y and (0.02-7.49)mSv/y with an average value(1.43)mSv/y for closed and open dosimeters respectively, which are less than the lower limit of the recommended range (3-10 mSv/y) (ICRP, 1993). The values of equilibrium factor vary from(0.008-0.94) with an average value(0.18) Which is less than the value adopted by the(UNSCEAR, 2000).