Radon diagnosis procedures focused on dwellings with ineffective measures against radon.

An efficiency analysis of remedial measures launching in the Czech Republic before 2004 revealed that in 52% of houses the remediation was not successful. An example of the house with an ineffective mitigation is described in order to present radon diagnosis procedures focused on the identification of critical factors responsible for the remedial mitigations insufficiency. A description of additional measures application is presented and results of the final efficiency evaluation are discussed.