Mitigation of ineffective measures against radon.

Reasons of low effectiveness of radon remedial measures have been studied on several unsuccessfully remediated houses. Based on the thorough analysis, factors responsible for failures are clarified. The possibilities of how to improve the effectiveness of installed measures are also discussed. Experience in this field is documented by several examples of additionally mitigated houses. After application of additional measures, indoor radon concentration in the studied houses decreased in average 5.3 times. Costs for additional mitigation were at least four times cheaper compared with costs required for installation of original measures.