Dr. Tsubokura's Radiation Lecture Vol.51
Author: Masaharu Tsubokura
Editors: Akihiko Ozaki M.D., Yuki Senoo
101. The level of radiation exposure in Fukushima too low to increase cancer risk
Radiation exists in our surrounding environment; all of us have been exposed to radiation to some extent in our everyday lives. The impact of radiation on health is determined by the extent of the exposure dose, not by whether one has experienced exposure in the past.
In that case, what extent of radiation exposure is deemed dangerous? The result of the health survey conducted after the atomic bombings of Hiroshima and Nagasaki provides us the best answer to this question: of course, nuclear weapons must never be used again.
This survey was launched by the Atomic Bomb Casualty Commission (ABCC) under the federal government of the United States and the Radiation Effects Research Foundation under the Japanese government in 1950. Since then, these entities have continuously investigated long-term radiation-related health effects. This survey covers 120 thousand residents and data such as the distance from the epicenter, radiation exposure doses, cancer incidence, and cause of death.
The findings we obtained upon the sacrifice of millions of people in Hiroshima and Nagasaki shows that after the nuclear power plant accident in Fukushima, the residents experienced a much lower level of radiation exposure compared to the dose that increases cancer incidence (approximately 100-200 millisieverts).
102. There is no “good” or “bad” radiation
The impact of radiation on health is determined by the extent of the exposure dose, not by whether one has experienced exposure in the past. In that case, what extent of radiation exposure is deemed dangerous? Numerous investigations have been conducted to find answers to this question.
The radiation-related health effects assessment conducted after the atomic bombings in Hiroshima and Nagasaki is one famous example, but there are many other studies as well. For example, there are studies on 1) medical radiation and health risks related to radiation exposure from diagnostic radiology examinations and treatments; 2) natural background radiation that exists in the environment; 3) occupational radiation exposure and radiation in workplaces such as nuclear power plants and other nuclear facilities.
The results of these investigations have been repeatedly compared to establish whether there is any contradiction, and through these processes, the relationship between the level of radiation exposure and health effects has been revealed. Researchers were able to compile data from various types of investigations because the impact of radiation on health is determined by the extent of the exposure dose; the reason for exposure is irrelevant. The impact of radiation on cells in our bodies does not differentiate between natural or artificial radiation and between internal or external exposure. Scientifically speaking, there is no good or bad radiation.
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The Japanese version of the manuscript was originally published in Fukushima Minyu, a local newspaper in Fukushima prefecture, Japan, on December 11st and 18th 2016 was reproduced for MRIC Global under the author's permission.