Abstract
The present study deals with measurement of indoor radon concentrations in dwellings of the district Poonch of the state of Azad Jammu and Kashmir, Pakistan. In this context, CR-39-based box-type radon detectors were installed in drawing rooms and bedrooms of 80 selected houses and were exposed to indoor radon for 3 months. After exposure, the CR-39 detectors were etched for 9 h in 6 mol NaOH at 70°C and the observed track densities were related to radon concentrations. Measured indoor radon concentrations in the studied area ranged from 27 ± 6 to 169 ± 4, 29 ± 6 to 196 ± 4 and 31 ± 5 to 142 ± 2 Bq m−3 in the drawing rooms and 74 ± 5 to 172 ± 3, 32 ± 6 to 191 ± 4 and 27 ± 5 to 155 ± 2 Bq m−3 in bedrooms of the Abbaspur, Hajira and Rawalakot regions of the district Poonch, respectively; whereas weighted average radon concentration ranged from 93 ± 6 to 159 ± 4, 33 ± 5 to 118 ± 3 and 31 ± 6 to 155 ± 5 Bq m−3 in the dwellings of Abbaspur, Hajira and Rawalakot, respectively. Estimated doses due to the indoor radon ranged from 2.35 ± 0.15 to 4.00 ± 0.10, 0.83 ± 0.08 to 2.98 ± 0.08 and 0.78 ± 0.15 to 3.91 ± 0.13 mSv y−1 for Abbaspur, Rawalakot and Hajira, respectively. Comparing the current indoor radon results with those of the Health Protection Agency UK and US EPA (i.e. 200 and 148 Bq m−3) limits, majority of the houses surveyed in the present study are within the safe limits.