Dr. Tsubokura's Radiation Lecture Vol.149

Author: Masaharu Tsubokura M.D., PhD.

Editors: Akihiko Ozaki M.D.,PhD., Yuki Senoo MUDr.

297. No association between parental radiation exposure and children’s health

September 27, 2020

　An investigation of atomic bomb survivors in Hiroshima and Nagasaki demonstrated no detectable genetic effects, such as increased risk of cancer and other diseases, among the survivors' offspring (the second generation exposed to radiation). This article discusses the relation between parental radiation exposure and the health of their children in detail.

　First, I would like to explain the cancer risk among the offspring of the parents exposed to radiation. As various factors can contribute to cancer development, some offspring of atomic-bomb survivors died of cancer. However, according to a survey of approximately 40,000 offspring of atomic bomb survivors collected since 1958, there was no observable relationship between parental radiation exposure and cancer incidence among their children. In other words, analysis of the survey results revealed that the offspring of people who were exposed to high doses of radiation did not have a higher risk of developing cancer compared to the offspring of people who were not exposed to high doses of radiation.

　Second, I would like to discuss lifestyle-related diseases among the second generation of atomic-bomb survivors. This survey collected data from approximately 12,000 offspring of atomic-bomb survivors over five years, beginning in 2002. Similar to the survey regarding the cancer risk, the survey showed no association between parental radiation exposure and the incidence of lifestyle-related diseases in their children.

　The level of radiation contamination caused by the 2011 Fukushima Daiichi Nuclear Power Plant accident was several orders of magnitudes lower than that caused by the atomic bombing of Hiroshima and Nagasaki. Thus, the results obtained from the survey mentioned above provide strong evidence that radiation contamination caused by the accident did not reach high enough levels to cause concern about genetic effects.

298. Childhood cancer treatment has no genetic effect

October 04, 2020

　To date, several types of cancer are known to occur in childhood, such as leukemia, neural cancer (cancers of nerve cells), and germ-cell cancers (cancers emerging from the cells that later differentiate into eggs or sperm). Some of these cancers also occur in adults, but rarely.

　Although such childhood cancers are often difficult to detect, they share certain characteristics; they respond well to chemotherapy and radiotherapy, often better than adult cancers. With their cooperation, research was conducted to assess the incidence of chromosomal abnormalities, genetic disease, and congenital malformation among the children of survivors of childhood cancer who received radiotherapy.

A study conducted in the U.S. and Canada compared the incidence of chromosomal abnormalities, genetic disease, and congenital malformation in the offspring of the survivors of childhood cancer and their siblings. According to this study, there were no observable differences in genetic health risks between the two groups.

　Although only a small part of the body is exposed to radiation during radiotherapy, the level of radiation exposure caused by the 2011 Fukushima Daiichi Nuclear Power Plant accident was several orders of magnitudes lower than that used in radiotherapy. Thus, the results obtained from the study conducted on the offspring of childhood cancer survivors also provide strong evidence that radiation contamination caused by the accident did not reach high enough levels to cause concern about genetic effects.

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The Japanese version of the manuscript was originally published in Fukushima Minyu, a local newspaper in Fukushima prefecture, Japan, on 27th September and 4th October 2020 were reproduced for MRIC Global under the author's permission.