The variations of radon and its short-term decay products in living rooms

In order to estimate precisely the amount of radon in the living rooms the research on its volumetric activity in the individual houses was carried out. The average values of the volumetric activity in the 1-2 floor individual houses reach about 50 Bq/m(3). The comparison with the other countries indicates that such average values of the volumetric activity of radon in the living rooms aren't big. There was estimated the volumetric activity dependence 3 on the building floor where the measurements were taken. The values vary from 100 Bq/m(3) (in the cellar) to 40 Bq/m(3) (in the 2 floor). This shows that the soil under the building is the main source of radon. The usage of ventilation is evaluated by created model which calculates the amount of short - terrn decay products of radon in the accommodations. There was estimated that ventilation is one of the most effective means to reduce the amount of the decay products of radon.