Radio, T.V., microwave, visible light, u.v. Al stops 5.3 Mev 's from Po. Hence natural radioactivities are normally of little concern unless the parent nucleus has been inhaled or ingested in the body.
Radiation dose is the radiant energy absorbed per unit mass.
Brick and stone houses often have larger backgrounds. A single dental x-ray may involve 7 mSv to the skin. Exposures from nuclear power generating stations are nearly zero. For perspective on radiation exposure, Prof. Cameron of the UW Medical Physics Dept. suggests translating doses into a natural unit, the BERT defined as the B ackground E quivalent R adiation T ime. If a house has high radon levels, then the radon ingress usually is from air infiltration from soil beneath the house.