We are constantly exposed to a variety of natural and artificial sources of radiation. In fact, natural sources account for 86 per cent of all our radiation exposure. Artificial sources make up the other 14% and come mainly from the beneficial use of radiation in medicine. Radiation doses from other man-made or artificial sources such as the Sellafield reprocessing plant, the Chernobyl accident, occupational exposure, etc., account for less than 1 per cent of our total exposure.
