Assessment of Annual Effective Dose Due to the Indoor Radon Exposure in Districts Bagh and Kahuta of the Azad Kashmir, Pakistan

摘要

In continuation to our earlier studies concerning generation of the baseline indoor radon data, an indoor radon measurement survey was carried out in the districts Bagh and Kahuta, state of the Azad Jammu and Kashmir. In this context, 150 houses were selected in the aforesaid districts and CN-85-based box-type radon detectors installed in bedroom and living room of each house. The detectors were exposed to indoor radon for 3 months. After etching CN-85 detectors in 6 M NaOH at 70℃ for 3 h, the observed track densities were related to the indoor radon concentration using calibration factor of 0.0092 tracks cm~(-2) h~(-1) per Bq·m~(-3). The measured indoor radon concentration ranged from 56 to 124 Bq·m~(-3) and 61 to 106Bq·m~(-3) in the studied areas of districts Bagh and Kahuta, respectively. The mean annual effec- tive dose ranged from 1.42±0.15 to 3.12±0.10mSv·y~(-1) with an average of 2.16±0.13mSv·y~(-1) in the district Bagh and 1.54±0.14to 2.68±0.12 mSv·y~(-1) with an average of 2.17 ± 0.13 mSv·y~(-1) in the district Kahuta. These values are within the safe limits recommended by the World Heath Organization.