2018 No https://pubmed.ncbi.nlm.nih.gov/29897581/ Zhukovsky Africa Asia Europe North America Experimental Students Radon Preliminary assessment of the worldwide population weighted characteristics of radon concentration in children’s institutions is: arithmetic mean = 59 and geometric mean = 36 Bq/m3. Higher indoor radon concentrations in children’s institutions in comparison with the dwellings can be explained by characteristics of ventilation, attendance regime and construction features. Special protocol of measurements in the kindergartens and schools is required.