Indoor radon concentration measurement in the dwellings of district Poonch (Azad Kashmir), Pakistan

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 degrees 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.