Radiation is a natural phenomenon and it can’t be avoided. It is always present in the form of background radiation.
Natural sources of background radiation include:
- Rocks – some contain radioactive material
- Building materials
- Cosmic rays
- Radon – a gas released from radioactive materials in the ground. Radon is itself radioactive.
Human activities – nuclear tests, nuclear accidents – also contribute to background radiation.
Some places are more radioactive than others due to underlying geology. You also get a larger dose of radiation if you travel on a plane rather than remain at ground level. Medical procedures such as X-rays and CT scans give you a small dose of ionising radiation but MRI scans do not.
The average dose received from natural sources by a person living in the UK in one year is 2.2 mSv.
