Radiation is, and always has been, a natural part of our environment. Consequently, a range of different sources – both natural and man-made – contribute to our exposure to ionizing radiation in daily life.
Naturally occurring radiation is found in the food we eat, the water we drink and the construction materials used in our buildings, while terrestrial radiation also comes from soils enriched in naturally occurring uranium and natural forms of energy.
Ever since radiation was discovered, people have benefited from its use in medicine and industry. Today, man-made sources of radiation globally account for about 21% of our total exposure.