Are there serious long-term effects of the bombing of Hiroshima and Nagasaki?
In August 1945, when World War II was about to end, the United States dropped on the Japanese cities of Hiroshima and Nagasaki two atomic bombs -one with uranium and another with plutonium - that caused more than 200,000 deaths and the complete devastation of all nearby village.
The long-term effects of exposure to radiation increased cancer rates among survivors. However, according to a study published in the journal Genetics, the public perception of the health consequences such as cancer and malformations at birth- is exaggerated compared with reality.
"Most people, including many scientists, have the impression that all the survivors have poor health and face very high rates of cancer or genetic mutation," said Bertrand Jordan, author of the study and molecular biologist at Aix-Marseille University in France.
The study takes into account more than 60 years of medical research on survivors of Hiroshima and Nagasaki and their following generations. "There is a huge difference between belief and what actually dictate the studies," says the researcher.
The attacks had immediate consequences. The explosive charge generated a firestorm that poisoned with acute radiation approximately 166,000 people in Hiroshima and 80,000 in Nagasaki.
About half of those who survived became part of follow-up studies of their health, which began in 1947 and still continues at the Foundation for Research on the Effects of Radiation, with funding from the governments of Japan and the USA. The project has followed approximately 100,000 survivors, 77,000 of their children, and more than 20,000 people that were not exposed to radiation.
This data set has been and is useful for quantifying the health risks resulting from exposure to a radiation source and to set the distance and the maximum acceptable exposure for workers in the nuclear industry.
According to the research, although it has been shown that exposure to radiation increases the risk of cancer, especially in young women, life expectancy of survivors dropped only by afew months compared to those who had not been exposed.
In fact, most of the survivors failed to develop oncological diseases. According to the results, the incidence of solid tumors between 1958 and 1998 in survivors was 10% higher, corresponding to 848 cases among the 44,635 survivors under study.
People exposed to a dose of radiation above gray - levels approximately 1,000 times higher than current safety limits for the general public - had a risk of 44% higher to develop cancer during the same period (1958- 1998). These doses, according to the report, reduced the average lifespan by about 1.3 years.
Although we have not found differences in the health of children of the survivors, Jordan suggests that the effects may come someday afloat, perhaps through more detailed sequencing of their genomes.
Jordan attributed the difference between the actual results and public perception to a variety of factors, among which is the historical context.
"People fear more the new and unknown dangers that those that are familiar," says Jordan. "For example, we tend to underestimate the danger of coal, both in people who extracts it as in those who breathe it every day because air pollution, "says the researcher.