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BOOKLET to Provide Basic Information Regarding Health Effects of Radiation (3rd edition)

Natural Radioactive Materials in the Body and Foods

Natural Radioactive Materials in the Body and Foods_Figure

Potassium is an element necessary for life and is contained in most foods. Because 0.01% of potassium is radioactive, most foods contain radioactive potassium. Radioactive potassium emits β-particles and γ-rays, causing internal exposure from food intake (p.74 of Vol. 1, "Visualized Radiation"). The internal potassium concentration is held constant, so exposure doses from potassium in foods depend on individuals' physiques and are considered unaffected by diet (p.8 of Vol. 1, "Naturally Occurring or Artificial").

The values for dry foods in the list are those analyzed in their product states, which include the effects of concentration increases due to drying. For example, if the weight decreases to one-tenth through drying, concentration increases by ten times.

  • Included in this reference material on March 31, 2013
  • Updated on February 28, 2018
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