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NCI Dictionary of Cancer Terms

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NCI Dictionary of Cancer Terms



ionizing radiation  listen  (I-uh-NY-zing RAY-dee-AY-shun)

  A type of radiation made (or given off ) by x-ray procedures, radioactive substances, rays that enter the Earth's atmosphere from outer space, and other sources. At high doses, ionizing radiation increases chemical activity inside cells and can lead to health risks, including cancer.