Exposure Dose from Natural and Artificial Radiation
We are exposed to radiation in our daily lives without realizing it.
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.63 of Vol. 1, "Comparison of Exposure Doses per Year").
The percentage of medical exposure from radiological examinations is known to be high in Japan. This is considered due to the fact 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.
- Included in this reference material on March 31, 2013
- Updated on March 31, 2015