Indoor radon measurements and annual effective dose estimation in different university workplaces in Urbino (Central Italy)

Background and aim. Radiation is a natural part of the environment, and radon gas is a critical source of exposure due to its abundance and mobility. Indeed, radon can reach and accumulate in confined living and working places. Inhalation of radon and its decay progenies is a significant risk factor for human health. This investigation aims to measure the annual average of radon concentration in in different workplaces of Urbino University. Methods. The study was carried out for two consecutive semesters in 48 workplaces using CR-39-type detectors. Results. The data revealed a mean value of radon concentration of 113.10 Bq/m3, higher than the national average value of 70 Bq/m3 but below the 300 Bq/m3 threshold indicated by Directive 96/29 EURATOM 2013. In the locals with higher radon levels (>300 Bq/m3), the effective dose estimation showed values below the limit of 6 mSv (from 3.27 to 5.12 mSv), except for one workplace identified as a technical room (no frequented by personnel). Discussion. Overall, in this investigation, 85.4% of the examined premises were below the reference level for indoor radon concentration (300 Bq/m3), while14.6% showed radon concentration higher than 300 Bq/m3 but in areas little or no frequented by staff at all, such as technical rooms (21.4%) and archives (20%), or libraries (37.5%) respectively. Conclusions. Our results confirm the presence of indoor radon in underground workplaces of Urbino University below the national reference level for indoor radon concentration in the air. In cases where radon values exceed this limit, the necessary interventions will be carried out, as well as new measurements to verify the effectiveness of the applied radiation protection procedures.