Workplaces built on highly permeable soils, where radon measurement in the workplace is required
The most significant source of radon in indoor air in workplaces is the soil beneath the building. Buildings are often depressurised, so replacement air may absorb directly from the soil into the building through gaps in the foundation. If the soil beneath the building is highly permeable to air, radon will transport effectively in the soil.
Gravel and sand are the most permeable soils. Workplaces located on sand ridges and gravel areas can be identified by looking at the landscape around the workplace. In cases of doubt, it is advisable to use the GTK map data which can be used to check whether the workplace is located in such an area.