Risk Assessment of Radon Exposure Inside Residential Dwellings in Safi City, Morocco

A radon study was conducted in 50 residences in Safi city, Morocco, using LR-115 detectors. The annual effective dose and Excess Lifetime Cancer Risk were also estimated. The measured radon concentrations ranged between the Lower Limit of Detection (LLD) and 132 Bq.m-3 with an arithmetic mean of 53 Bq.m-3 and a geometric mean of 41 Bq.m-3 (2.32). The results indicated that 58% of the obtained values exceeded the worldwide average value (39 Bq.m-3). In addition, the results revealed significant impacts of floor level and region on indoor radon levels. Inhabitants of the surveyed houses were found to receive a mean annual effective dose of 1.5 +/- 0.1 mSv.y-1, corresponding to an Excess Lifetime Cancer Risk of 0.6%. Importantly, all annual effective dose values were below the recommended action level by the ICRP (3-10 mSv.y-1). Using the Ordinary Kriging method implemented in the QGIS software, an indoor radon map was created based on the collected data. The findings in this study serve as baseline values for future studies concerning radon concentrations and their fluctuations.