RADON RISK ASSESSMENT IN SLOVAK KINDERGARTENS AND BASIC SCHOOLS

The results are presented of long-term measurements obtained during th e radon survey in the schools of the Slovak Republic. Measurements of equilibrium equivalent radon concentrations (EER) were performed in 64 5 buildings. It was found that the action level of EER was exceeded in 16 schools. Consequently short-term radon measurements were institute d in a kindergarten in Roznava-Cucma, where the highest level of EER w as measured. The analysis of the results contains the comparison of th e long- and short-term measurements, the influence of the spring and s ummertime, the daily radon variations and the radon source localisatio n. From the results obtained the annual effective doses from radon exp osure, estimated for pupils and teachers in the kindergarten, were 7 m Sv and 10.5 mSv, respectively. It is concluded that the real values of annual effective doses, estimated for pupils and teachers in schools are about 5 times lower than doses estimated from the results of integ ral long-term measurements due to the ventilation regime.