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How Can Exposure Occur?


  • People are exposed to small amounts of radiation every day, both from naturally occurring sources (such as elements in the soil or cosmic rays from the sun), and man-made sources. Man-made sources include some electronic equipment (such as microwave ovens and television sets), medical sources (such as x-rays, certain diagnostic tests, and treatments), and from nuclear weapons testing.
  • The amount of radiation from natural or man-made sources to which people are exposed is usually small; a radiation emergency (such as a nuclear power plant accident or a terrorist event) could expose people to small or large doses of radiation, depending on the situation.
  • Scientists estimate that the average person in the United States receives a dose of about one-third of a rem per year. About 80% of human exposure comes from natural sources and the remaining 20% comes from man-made radiation sources – mainly medical x-rays.
  • Contamination refers to particles of radioactive material that are deposited anywhere that they are not supposed to be, such as on an object or on a person’s skin.
  • Internal contamination refers to radioactive material that is taken into the body through breathing, eating, or drinking.
  • Exposure occurs when radiation energy penetrates the body.


Created at 7/8/2014 4:48 PM by Webmaster
Last modified at 7/8/2014 4:48 PM by Webmaster