Radon Exposure Assessment for Sewerage System’s Workers in Naples, South Italy

An indoor radon survey has been carried out in 17 workplaces of sewerage system of Naples city using E-Perm detectors in long-term configuration. The main objective was to assess the mean effective dose for workers. The measured indoor radon concentration ranged from 1714 to 3789 Bq m−3 in the rooms located on second level underground, from 138 to 5772 Bq m−3 in the rooms on first level underground and from 53 to 913 Bq m−3 in the ground floor. The mean annual effective doses in the ground floor, first and second level underground were found to be 0.85 mSv, 0.29 mSv and 0.43 mSv, respectively. These values are less than the lower limit of International Commission on Radiological Protection (ICRP) recommended action levels of 3–10 mSv y−1.