Dr. Tsubokura's Radiation Lecture Vol.111
Author: Masaharu Tsubokura PhD.
Editors: Akihiko Ozaki M.D.,PhD., Yuki Senoo
221. Radiation exposure in preceding generations has not caused any harms to their descendants.
There have been persistent public concerns that additional radiation exposure caused by the 2011 Fukushima Daiichi nuclear accident will inflict adverse health effects on our future generations. However, considering the current circumstances, radiation exposure caused by the Fukushima Daiichi nuclear accident is unlikely to cause any genetic health effects among the next generations.
Some people might say that radiation damage on germ cells, such as sperm cells and oocytes, may cause adverse genetic effects in children of those who received radiation exposure. Here, I would like to explain why there is no need to be concerned about effects of radiation on future generations.
One explanation is that there were no hereditary effects of radiation exposure among the offspring of atomic bomb survivors in Hiroshima and Nagasaki.
Since the end of World War Ⅱ, investigations on the aftereffect of radiation on over 70,000 newborns have been continuouslyconducted in Hiroshima and Nagasaki. The results of the long-term investigations have presented no difference in the incidence of birth defects, chromosomal abnormalities or mutations, hereditary diseases in the pre- and post-natal periods, or early neonatal deaths in newborns whose parents received high-dose radiation exposure and newborns whose parents who did not.
The estimated average dose of radiation exposure that parents and thus their germ cells received in the atomic bombings was several hundred millisieverts, which is an order of magnitude higher than the radiation exposure level caused by the Fukushima Daiichi nuclear accident. Even after the atomic bombings of Hiroshima and Nagasaki, where radiation exposure occurred that was higher by an order of magnitude, there were no genetic effects of radiation observed on children. This evidence provides one reason why there is no need to worry about genetic effects caused by the Fukushima Daiichi nuclear accident. .
222. For the same dose, radiation delivered over a long time has a lower health risk than that delivered over a short period.
There have been persistent public concerns that additional radiation exposure caused by the 2011 Fukushima Daiichi nuclear accident will cause adverse health effects to our future generations. However, considering the current circumstances, such exposure is unlikely to cause any genetic health effects among the next generations.
The previous article explained how past research demonstrated no significant genetic effect of radiation observed in the children of atomic bomb survivors in Hiroshima and Nagasaki, even though their parents received radiation exposure higher than that of Fukushima Daiichi nuclear accident victims by an order of magnitude.
Additionally, in cases in which the same total dose of radiation is received, the health impact of radiation exposure is much less harmful when it happens over a long period than when it happens over a short one. This effect holds because when a person receives a small dose of radiation for a long time, the body is able to recover from the damage caused by radiation. This effect might be made more clear by mentally replacing radiation with alcohol: drinking a lot of alcohol in one go is more dangerous than taking sips for a long time that come out to the same amount.
At the time of the atomic bombings in Hiroshima and Nagasaki, people were exposed to an extremely high radiation dose within an instant of each explosion. On the other hand, this was not the case with the Fukushima Daiichi nuclear accident. In Fukushima, the level o