What impact does heavy rainfall or frost have on soil permeability near a house?

Heavy rainfall or frost can significantly affect soil permeability, which in turn impacts how gases, including radon, enter homes. When soil becomes saturated with water due to heavy rainfall, or when the ground is frozen during frost conditions, the soil's ability to allow air—and thus gases—to move through it decreases. This reduced permeability means that radon, which typically enters homes through cracks and openings in the foundation, is less able to migrate from the soil into the home.

In the context of radon measurement, it is important to recognize that while moisture or frost may limit the entry of soil gas, radon levels can fluctuate when conditions change. However, during the conditions specified—heavy rain and frost—there is a temporary reduction in soil gas entry, including radon.

Understanding this relationship between soil conditions and radon entry is crucial for accurate radon measurement and mitigation strategies. This comprehension helps ensure proper evaluation of radon risks in homes, particularly following significant weather events or seasonal changes.