The indoor concentration of radon daughters in three different areas of the U.K.

The concentrations of radon daughters were measured in 86 rooms in three different areas in U.K.: Birmingham, Aberdeen and mainland Orkneys. The geometrical means of the concentrations in these areas were found to be 2.0, 6.7, and 2.5 mWL, respectively. In many cases, the ground beneath the houses was an important source of radon; where there was good sub-floor ventilation, the ground contribution was not important.