Measurement and comparison of indoor radon levels in new and old buildings in the city of Muzaffarabad (Azad Kashmir), Pakistan. A pilot study

Indoor radon concentrations have been measured in a limited number of dwellings in the state capital of Azad Jammu and Kashimir, Muzaffarabad city after the devastating earthquake of 2005. Radon detectors (CN-85 based box-type) were placed in the drawing rooms, bedrooms and kitchens of 35 houses, selected on the basis of their location and design as well as willingness and cooperation of householders from mid May to mid July 2007. The average radon concentrations were found to vary from 24 to 518 Bq m-3, 41 to 380 Bq m-3 and 32 to 467 Bq m-3 in the bedrooms, drawing rooms and kitchens, respectively. The weighted average radon concentration in older houses was found to vary from 51 to 334 Bq m-3 and for newly constructed houses a considerable decrease in measured values (ranging from 14 to 102 Bq m-3) have been found. As Pakistan does not currently have a national reference (or action level) for radon in homes, therefore the present data has been compared with the data reported for other countries. Some of the houses studied were found to have higher radon concentrations. These higher values of indoor radon levels may be due to the poor ventilation and influence of the earthquake in creating new fissures and therefore new pathways for radon to enter into the buildings. (author)