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Japanese population dose from natural radiation
Yasutaka Omori1, Masahiro Hosoda, Fumiaki Takahashi
1Ad hoc Committee of Japanese Population Dose Estimation of Japan Health Physics Society, Yoshimatsu Buid. 3F, 3-7-2 Shimbashi, Minato-ku, Tokyo 105-0004, Japan. Department of Radiation Physics and Chemistry, School of Medicine, Fukushima Medical University, 1 Hikarigaoka, Fukushima 960-1295, Japan.
Summary
The total annual effective radiation dose from natural sources in Japan is 2.2 mSv, comparable to the global average. This review covers cosmic rays, terrestrial radiation, inhalation, and ingestion for the Japanese population.
Area of Science:
- Environmental Science
- Radiological Protection
- Public Health
Background:
- Natural radiation sources contribute significantly to the overall radiation dose received by the public.
- Accurate assessment of natural radiation doses is crucial for understanding potential health risks and informing radiation protection policies.
- Previous assessments in Japan varied due to different methodologies in nationwide surveys.
Purpose of the Study:
- To review and consolidate current knowledge on radiation doses from natural sources in Japan.
- To provide an updated estimation of the annual effective dose for the Japanese population from various natural radiation pathways.
- To compare the estimated Japanese population dose with the global average.
Main Methods:
- Compilation and analysis of data from the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) and the Nuclear Safety Research Association.
- Evaluation of annual effective dose from cosmic-ray exposure.
- Utilizing nationwide survey data from the National Institute of Radiological Sciences for terrestrial radiation.
- Employing Japan Chemical Analysis Center (JCAC) data for radon and thoron inhalation doses.
- Analysis of JCAC survey data on foodstuffs for committed effective dose from dietary intake.
Main Results:
- The annual effective dose from cosmic-ray exposure is 0.29 mSv.
- The mean annual effective dose from external terrestrial radiation is 0.33 mSv.
- The estimated annual effective dose from radon and thoron inhalation is 0.59 mSv.
- The committed effective dose from dietary intake of radionuclides is 0.99 mSv.
- The total annual effective dose from natural radiation for the Japanese population is 2.2 mSv.
Conclusions:
- The total annual effective dose from natural radiation in Japan (2.2 mSv) is similar to the global average (2.4 mSv).
- This comprehensive review provides an updated baseline for natural radiation exposure in Japan.
- Findings underscore the importance of continued monitoring and assessment of natural radiation sources.
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