The incidence and origin of radon and its decay products in buildings.

The largest contribution to population exposure from natural radiation arises from the inhalation of the decay products of radon in indoor air. In most instances the dominant source of radon within buildings is the subjacent ground. However, building materials do contribute to the radon concentration in indoor air, and in some circumstances may provide the major source. Thisreport reviews some of the literature on radon emanation from soils and building materials world-wide. Details are given of measurements of radon emanation from common UK building materials, together with results of measurements of radon concentration in indoor air in sedimentary areas and in areas of enhanced uranium mineralisation.