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

Exposure Dose from Natural and Artificial Radiation

Exposure Dose from Natural and Artificial Radiation_Figure

Radiation exists around us and we are exposed to it in our daily lives without realizing. It is impossible to completely avoid radiation exposure in our daily lives.

External exposure to natural radiation from outer space and the ground, and internal exposure to naturally occurring radioactive materials, such as those in foods and radon in the air, amount to a global average of 2.4 mSv and a Japanese average of 2.1 mSv annually (p.65 of Vol. 1, "Comparison of Exposure Doses per Year").

The percentage of medical exposure from radiological examinations is known to be high in Japan. The annual average medical exposure in Japan is estimated to be 2.6 mSv. This is considered due to the fact that an environment to ensure easy access to healthcare has been developed under the universal health insurance system and that CT scans, which involve high-dose exposure per examination, are quite common and upper gastro intestinal (UGI) examination is generally utilized for stomach cancer screening in Japan. In 2015, the diagnostic reference levels for medical exposure were established (revised in 2020), and efforts for optimizing medical exposure are now being made (p.76 of Vol. 1, "Radiation Doses from Medical Diagnosis").

  • Included in this reference material on March 31, 2013
  • Updated on March 31, 2022
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