Assessment of radon levels in indoor workplaces in Tunisia and associated radiological risks

This study aimed to assess indoor radon levels within different workplaces in Tunisia, including universities, schools, spa centres, and phosphate fertiliser factories. A total of 110 locations within these workplaces were monitored using solid-state nuclear track detectors (LR 115). The obtained results indicated that the geometric mean (GM) values of indoor radon concentrations measured at these locations were 24.6 Bq m-3 for universities, 31.3 Bq m-3 for schools, 72.2 Bq m-3 for spa centres, and 70.0 Bq m-3 for phosphate fertiliser factories. Overall, the GM of indoor radon concentrations measured in the four studied workplaces remained below standard values. Statistical analysis using the two-sample Student t-test revealed significant differences between the workplaces. The calculated annual effective doses due to radon inhalation were found to have GM values of 0.2 mSv y-1 for universities, 0.2 mSv y-1 for schools, 0.5 mSv y-1 for spa centres, and 0.4 mSv y-1 for phosphate fertiliser factories. These values are comparable to worldwide average values. Other risk parameters, such as lung cancer risk and lung cancer cases were also determined and reported in this study. While this study did not investigate the factors influencing radon concentrations, its primary advantage lies in being the first comparative study monitoring various workplaces in Tunisia, covering both underground and above-ground settings.