As soil and building materials contain these natural radionuclides, the dose we received therefore depends on the geological composition of the place we live and the building materials we use.

• 地壳土壤及建筑材料内,都含有这些天然的放射性核素,因此我们吸收到的天然辐射剂量与所在地区的土质成份有关,亦与我们居所的建筑物料有关。