INFLUENCE OF BUILDING FEATURES ON RADON ACCUMULATION IN KINDERGARTENS OF THE SVERDLOVSK REGION

Objective: To study the levels of radon accumulation in kindergartens in Sverdlovsk Region and to deter­mine the relationship between radon concentration, and building characteristics. To perform a detailed anal­ysis of radon entry and accumulation in the kindergarten, in which radon concentration exceeds the safety standards.

Materials and methods: Track detectors REI-4 on the base of LR-115 film were used. Detectors were installed in playrooms and bedrooms for day nap. In each kindergarten, at least 3 rooms were examined. The measurements were carried out twice a year, during the warm and cold seasons. The duration of exposure of the detectors was 2–3 months in each season. The AlphaGUARD radon monitor was installed in the kinder­garten with a high level of radon concentration.

Results: It is shown that the distribution of radon concentration in the kindergartens of the Sverdlovsk region can be described by a lognormal distribution with an average value of 60 Bq/m3, a geometric mean of 44 Bq/m³ and a standard geometric deviation of 2.23. A statistically significant differ­ence was found between the mean values of radon concentration in subgroups of buildings constructed at different periods. For the kindergartens constructed in 1950–1969, the average radon concentration was 85 Bq/m³, for buildings built in 1970–1989 – 54 Bq/m³. When comparing subgroups of rooms with different types of windows (all buildings, ground floors) it was found that in rooms with PVC windows, radon concentration is almost twice as high then in rooms with wooden windows. For the kindergarten, in which the annual radon concentration in the playroom was 620 Bq/m³, it was shown, that if the proper ventilation regime of this room is observed, the average radon concentration during the presence of children does not exceed 120 Bq/m³.

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