A new study revealed that the public perception about the long-term health effect of the detonation of atomic bombs in Hiroshima and Nagasaki are highly exaggerated.

"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," said Bertrand Jordan, an author and a molecular biologist at UMR 7268 ADéS, Aix-Marseille Université/EFS/CNRS, in France, in a statement. "There's an enormous gap between that belief and what has actually been found by researchers."

The study, published in the journal Genetics, showed that the average lifespan of the survivors of both bombings was reduced by only a few months, despite the increased risk of cancer due to radiation exposure, compared to those who were not exposed to radiation.

For the study, the researchers summarizes 60 years worth of data 100,000 survivors, 77,000 of their children, plus 20,000 people who were not exposed to radiation.

It is widely accepted that radiation exposure increases the risk of cancer. However, the researchers observed that the relative risk increased according to how close the person was to the detonation site, their age and sex.

Younger people and women have a greater life time risk. Additionally, people who were exposed to a higher radiation dose of 1 Gray (approximately 1000 times higher than current safety limits for the general public) have 44 percent increased risk of developing cancer.

Although the incidence of solid cancers between 1958 and 1998 among the survivors were 10% higher, a relatively high dose of radiation exposure only reduced the average lifespan of survivors by 1.3 years.

So far, no differences in health and mutation rates were detected among the children of the survivors. However, the researchers warned that subtle effects might one day become evident.

Even if the children of the survivors do in fact have to face additional health risk, the researchers believe that those risks will be very small.