The atomic bombings of Hiroshima and Nagasaki in 1945 exposed hundreds of thousands to intense heat and ionizing radiations. Long-term health studies of the survivors may provide insight into the radiation-related effects occurring in Japan now.
The latest issue of Disaster Medicine and Public Health Preparedness, published by the American Medical Association, shares lessons learned from following the survivors for 63 years.
A quick timeline:
- President Harry Truman approved the original directive to study the biological and medical effects of the atomic bomb on humans.
- In 1947, the Atomic Bomb Casualty Commission (ABCC) was created.
- The Life Span Study was instituted in 1955 to follow-up on mortality and cancer incidence of a sample of about 120,000 atomic bomb survivors and control subjects.
- The ABCC was restructured in 1975 to become the Radiation Effects Research Foundation (RERF) to continue research on the health the atomic bomb survivors and their children, with financial and scientific support from the Japanese and US governments.
According to the review article, approximately 40% of the atomic bomb survivors are alive today. This includes about 80% of those who were exposed before they were 20 years old – which carries a higher risk.
Among the atomic bomb survivors, researchers have found:
- Increased risk of leukemia.
- Gradual increase in solid cancers starting several years after bombings. Survivors received whole-body exposures from the penetrating radiation, leading to significant cancer risks in the oral cavity, esophagus, stomach, colon, liver, lung, skin, breast, ovary, urinary bladder, brain/central nervous system, and thyroid.
- Reduction in life span – due to solid cancer, leukemia, and noncancer diseases such as chronic hepatitis – anywhere from 2 months to 2.6 years depending on the radiation dose.
With respect to the search for radiation-induced mutations and risk to succeeding generations, the authors write, the goal is that future studies using newer DNA analyses will be able to detect an elevated mutation rate (if one exists) or confirm the low mutation rate they observed in the second generation.
These atomic lessons, they hope, can serve future generations who experience occupational, medical, or environmental radiation exposures.
Image: Hiroshima and Nagasaki after the bombings / E.B. Douple et al.