2.7 mSv
UK average
annual radiation dose

What is a millisievert?
For ionising radiation (X-rays, gamma-rays, electrons, neutrons etc.) the quantity of absorbed energy is called a "dose" and is measured in sieverts (Sv). A sievert is a very large and extremely unusual dose so more often we talk about thousandths of a sievert - a millisievert.

Ionising radiation can be found in soils, in our air and water, and in us. Because it occurs in our natural environment, we encounter it every day through the food we eat, the water we drink, and the air we breathe. It is also in building materials and items we commonly use. The UK Health Security Agency and its predecessor organisations have calculated the exposure of the UK population from naturally occurring and artificial sources of ionising radiation periodically since 1974.

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Contributions to the average dose in the UK

Comparison of doses from sources of exposure