Radiation risks Long-term health effects of atomic bombs dropped on Japan not as dire as perceived

Published 16 August 2016

The detonation of atomic bombs over the Japanese cities of Hiroshima and Nagasaki in August 1945 resulted in horrific casualties and devastation. The public perception of the long-term effects of radiation exposure, however, is, in fact, greatly exaggerated. New studies, summarizes over sixty years of medical research on the Hiroshima/Nagasaki survivors and their children, have clearly demonstrated that radiation exposure increases cancer risk, but also show that the average lifespan of survivors was reduced by only a few months compared to those not exposed to radiation. No health effects of any sort have so far been detected in children of the survivors.

The detonation of atomic bombs over the Japanese cities of Hiroshima and Nagasaki in August 1945 resulted in horrific casualties and devastation. The long-term effects of radiation exposure also increased cancer rates in the survivors. But public perception of the rates of cancer and birth defects among survivors and their children is in fact greatly exaggerated when compared to the reality revealed by comprehensive follow-up studies. The reasons for this mismatch and its implications are discussed in a Perspectives review of the Hiroshima/Nagasaki survivor studies published in the August issue of the journal Genetics, a publication of the Genetics Society of America.

Most people, including many scientists, are under the impression that the survivors faced debilitating health effects and very high rates of cancer, and that their children had high rates of genetic disease,” says Bertrand Jordan, an author and a molecular biologist at UMR 7268 ADÉS, Aix-Marseille Université/EFS/CNRS, in France. “There’s an enormous gap between that belief and what has actually been found by researchers.”

Dr. Jordan’s article contains no new data, but summarizes over sixty years of medical research on the Hiroshima/Nagasaki survivors and their children and discusses reasons for the persistent misconceptions. GSA notes that the studies have clearly demonstrated that radiation exposure increases cancer risk, but also show that the average lifespan of survivors was reduced by only a few months compared to those not exposed to radiation. No health effects of any sort have so far been detected in children of the survivors.

Approximately 200,000 people died in the bombings and their immediate aftermath, mainly from the explosive blast, the firestorm it sparked, and from acute radiation poisoning. Around half of the those who survived subsequently took part in studies tracking their health over their entire lifespan. These studies began in 1947 and are now conducted by a dedicated agency, the Radiation Effects Research Foundation (RERF), with funding from the Japanese and U.S. governments. The project has followed approximately 100,000 survivors, 77,000 of their children, plus 20,000 people who were not exposed to radiation.