The Radon programme in the Czech Republic has a relatively long and rich history. Procedures, which enable to evaluate the risk of radon penetration from the ground, to protect new buildings, to find existing buildings with elevated indoor radon levels and to realize remedial measures in such buildings, have been developed, published and tested.

In a majority of cases, the whole system brings good results and leads to a decrease of indoor radon concentrations. But sometimes it may fail, or it may bring a poor effect only due to human errors, or due to other psychological, or sociological reasons.

Example A: Human behavior affecting measurement results

The indoor radon concentration significantly changes in time and it may be strongly influenced by inhabitant’s behavior.

Integral methods are mostly used for indoor radon concentration measurements. Moreover, integral detectors are located and collected by non-specialists very often.

For all these reasons, the measurement of indoor radon concentration may be affected by the owner of the house, or by people who live in the house: knowingly, or unknowingly. A wide spectrum of cases is observed in practice:

• an unsuitable location of integral detectors - integral detectors located in rooms that are declared as habitable rooms (for example as living rooms), but that are used for other purposes (as storerooms);
• extraordinary conditions during the exposure of integral detectors, for example a long-term reconstruction of floors in the house

… the measurement was influenced unknowingly;

• people want „to avoid any problems“ and they increase the ventilation of rooms, where the detectors are located;
• people want to get financial support from the government for a realization of remedial measures in the house and they reduce the ventilation;
• people like „experiments“ and they place several detectors together in the same room to check if the laboratory works well, or not;
• people want „to safe money“ and they switch-off the sub-slab ventilation system.

… the measurement was influenced knowingly.

Notes: the above mentioned problems may appear in different part of the process: during the search for existing houses with elevated indoor radon levels as well as during the testing of the effectiveness of remedial measures.

Moreover, the information on the fact that the measurement has been affected is almost always lost. The only way how to get such information is to return to the house, to make a detailed investigation and to speak to people.

Example B: Conflict between individual and „all-society“ points of view

Radon programme is directed by central (national, state, governmental) institutions with the goal to decrease a collective dose. But the real target of any action is always an individual.

In some individual cases, a detriment connected with radon measurement and with realization of remedial measures (stress, discomfort) may be greater than a positive effect connected with lower indoor radon concentrations. This can be sometimes observed when old people live in an old building.