X-rays, Gamma Rays, and Cancer Risk

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How are people exposed to x-rays and gamma rays?

People may be exposed to this type of radiation from 3 main sources:

  • Natural background radiation comes from cosmic rays from our solar system and radioactive elements normally present in the soil. This is the major contributor to worldwide radiation exposure.
  • Medical radiation is used for x-rays, CT scans, and other tests, as well as for radiation therapy. Radiation therapy is used to treat some types of cancer and involves dosages many thousand times higher than those used in diagnostic x-rays.
  • Non-medical, man-made radiation is used in small amounts in food irradiation, airport security scanners, and some consumer products. Exposure to man-made radiation can happen in certain workplaces, or in communities as a result of above ground nuclear weapons testing and nuclear accidents.

Last Medical Review: 02/24/2015
Last Revised: 02/24/2015