Notes: According to p. 39 of the Radiation Safety Norms, during designing the residential and public buildings it should be envisaged that the summary of the annual average equilibrium activity concentration due to 222Rn and 220Rn daughter isotope (222Rn + 4.6 220Rn) shall not exceed 100 Bq/m3. According to p. 216 of Radiation Safety Rules, during site selection of building the residential constructions and housing and communal constructions the preference shall be given to those sites where the natural gamma radiation rate doesn’t exceed 0,3 µSv/hour, and the radon flux density on the ground surface is 80 mBq/m2/s. The territories allocated for building of residential construction where the radon flux density exceeds 80 mBq/m2/s, the construction design shall incorporate the system for protection against radon (moonlit concrete pad, special isolations of basement and other). 