Geological controls on radon potential in England

Radon exposure is a chronic and serious geohazard but with the correct knowledge of its distribution provided by an accurate radon potential map, this risk to human health can be reduced through well directed radon testing programmes and building control regulations. don potential map presented here, produced by mapping radon concentrations in homes, grouped by underlying geology, provides the most detailed and accurate assessment of radon in England. k and superficial geology associated with the most radon prone areas are investigated using the joint HPA-BGS radon potential dataset, geological information and, where available, soil geochemistry, airborne radiometric or laboratory analysis. f the geological units associated with high radon potential are well known, such as the granite intrusions in south west England, the Carboniferous limestones of Derbyshire and the Jurassic ironstones in Northamptonshire. This study provides a more comprehensive description of the main bedrock geological units associated with intermediate to high radon potential in England including: granites and associated uranium mineralisation in south west England; Devonian, Carboniferous, Permian and Jurassic limestones and dolomites; Devonian, Carboniferous, Jurassic and Cretaceous sandstones; Silurian, Devonian, Lower Carboniferous and Jurassic mudstones; Jurassic ironstones; and some Triassic breccias and conglomerates. Uranium in soil is elevated over many known radon-prone areas but also reflects the accumulation of U in organic-rich soil and peat. Near surface weathering, bedrock fracturing and former working of the ironstones in the English Midlands are all implicated in increased radon potential on these geological units.