Radiation hazards and lifetime risk assessment related to indoor and outdoor air inhalation using a passive detection technique

In this work, a passive detection technique is utilized to analyze radon, Rn-222, concentration levels in indoor and outdoor air after implanting 126 (CR-39) detectors for 130 days during the winter season in Irbid governorate, the second largest governorate in Jordan. Also, the spatial variations of the outdoor Rn-222 concentrations in the air were interpolated and mapped using ArcGIS. Kriging method has been found the finest, among other geostatistical methods, for generating outdoor Rn-222 concentration spatial interpolations with the least uncertainty and highest smoothness. The outdoor radon concentrations have ranged from 9 to 72 Bq m(-3), while the indoors' have started as low as 17 and up to 102 Bq m(-3). There was no clear realizable correlation among the identified indoor and outdoor air radon concentration levels. However, the calculated health risk indicators associated with radon inhalation show that around 11 residents in every 1000 could have an increased risk of lung cancer developing due to relatively higher radon gas exposure levels. These findings are important when applying radon policies both at the local and at the national levels, in terms of changing the air ventilation practices and for identifying areas of priority for further study, zoning, and land-use decision.