The presence of high concentrations of radioactive gas Radon-222 in residential and production premises exerts negative influence on the health state of the population and boosts the risk of coming into existence of respiratory system cancer. In this research, the analysis of main factors that exert influence on the content of Radon in premises of Rivne city is presented and the set of measures that minimize negative consequences of Radon influence on the health of the population both in the premises that are exploited and in the ones that are on the design stage is offered. We divide the city into the regions with different levels of radon danger that depend on the values of Radon volume activity (VA) in premises and the density of Radon flux (DRF) from the soil. The city territory was divided into 12 proving grounds and 48 sub regions for this purpose. Measuring VA in premises was performed in the time frame from 2013 to 2017 with the reliance on the express method and the Radon radiometer “Alpharad plus”. In total 600 premises were investigated. 185 of them are located under the ground level. 215 of them are only partially under the ground level. 200 of them are located on the first floor. VA of Radon-222, DRF from the ground, Radon concentration in the ground gas and water were determined experimentally. Risks of acquiring lung cancer on the part of the population of Rivne city were calculated. It is determined that the values of Radon VA in the premises under investigation range from 25 Bq/m3 to 1000 Bq/m3, the values of DRF from the soil range from 16 to 173 mBq/(m2 × s). Since the construction standard of the Radon flux from the ground is set at the level of 80 mBq/( m2 × s); 34%, 44%, and 22% of city premises have respectively low, medium, and high levels of safety. The results of this research imply that the regional and state programs of creating standards and collecting data for the analysis of the state of radioactive safety and for making practical decisions regarding measures that subdue risks due to population exposure to natural irradiation should be developed.