To protect the population from radon Environmental Protection Agency stated, in accordance with recommendations of the Inter - National Radiological Protection - ICRP , that "action level", ie the maximum permitted concentration of radon in residential, would be 200 Bq / cu. When the annual average concentration of radon in the room, accustomed to living conditions, exceeds the level of action, has to perform Lhktnto. to the concentration of radon in the room represented the annual average, can be compared with the level of action, have to try it for at least 3 months (in practice between 3 - 6 Months ) normal living conditions.
Radon concentration in depends, inter alia, the following factors:
- Ground: the concentration of radium, radon emissions from the ground, air pressure, temperature and humidity.
- Atmosphere: air movements, air pressure, temperature, humidity and weather.
- Additional building: construction material and construction method, the thickness of the floor or walls of detached homes.
- Ground openings: plumbing, gas, sewer, electricity, fractures or cracks in the floor.
- The level structure: basement, floor single-family homes, top floor.
- Sealing of the building: Sealing windows and doors, vents.
- Ventilation habits: frequency of opening and closing of doors and windows, ventilation system operation.
- Construction Materials: Hakshltzih rate (amount of radon emitted per unit area in unit time) from the walls, floor and ceiling, thick walls.