Radon concentrations in schools of the Neapolitan area

A radon survey was carried out in 30 schools located in the metropolitan area around Naples, Italy. Radon concentration was measured using the SSNTD (Solid State Nuclear Track Detectors) method with LR115 detectors. Time integrated measurements covered two consecutive 6-month periods at different locations inside the school buildings: classrooms, laboratories and offices. Data distribution is well fitted by a log-normal curve. The arithmetic mean annual radon concentration is 144 Bq m-3, the geometric mean is 86 Bq m-3; the standard deviations are respectively 7 Bq m-3 and 3. The fractions of rooms where radon concentrations exceed the reference levels of 200, 400 and 500 Bq m-3 are 21.3%, 7.6% and 4.5% respectively. The results show that radon concentration in scientific laboratories and in offices is higher than in classrooms