2017 Yes https://pubmed.ncbi.nlm.nih.gov/27919569/ Žunić, Z. S Europe Observational Other Elementary (K-5) Radon Indoor radon Dwelling School Sokobanja – southern serbia Spatial mean long-term temporal mean Rn concentration in dwellings is somewhat lower than in schools in the same town, where the spatial means refer to areas that extend typically 1 km. The ratio dwelling/school equals about 0.8, with large uncertainty. For dwellings close to schools (hypothetically collocated, realistically less than about 50 m away) the ratio is still a bit smaller, about 0.7.