Radon in schools of Montenegro

During the school year, radon (222Rn) was continuously measured with passive detectors in all public schools in Montenegro-345 primary and 47 secondary schools. Measurements were taken in all ground-floor classrooms and offices (2336 rooms in total), as well as in 182 first-floor rooms across 91 schools. On the first floor, the arithmetic mean (AM) of radon concentrations was 100 Bq/m3, and the median (MED) was 65 Bq/m3, with only five schools having rooms where radon levels exceeded 300 Bq/m3. On the ground floor of all 392 schools, the AM was 276 Bq/m3, and the MED was 146 Bq/m3. In 188 schools, some rooms had radon levels above 300 Bq/m3, and in 43 schools, certain rooms exceeded 1000 Bq/m3. An assessment of the effective annual doses from radon inhalation for pupils was also conducted. On average, the dose was 0.66 mSv per school year, although in some classrooms it reached up to 11 mSv.