The last surviving double hibakusha has died. Tsutomu Yamaguchi, who had the incredible fortune of surviving both atomic bombings in Japan, has succumbed at age 93 to stomach cancer, after leading an otherwise healthy life since he was in Hiroshima on August 6, 1945, and Nagasaki three days later. His story, and those of all the survivors, known in Japan as hibakusha, teach us many things. One of them is that ionizing radiation from nuclear energy is indeed a carcinogen. But it’s not nearly as potent a threat as many people believe. Another lesson is that our fear of nuclear radiation may actually be making things more dangerous, not less.
The atomic bombings of Hiroshima and Nagasaki created a horrible human experiment from which we have learned just what this type of radiation can do to human health. Nearly 90,000 hibakusha have been followed by epidemiologists for nearly 65 years. Scientists compared them to a non-exposed Japanese population, to see what the radiation exposure did. The current estimate is that 572 hibakusha have died prematurely from radiation-induced cancer. To many, that is a surprisingly small number.
Research by the international Radiation Effects Research Foundation (RERF) http://www.rerf.or.jp/ also found that the developing children of pregnant hibakusha women suffered horrible birth defects. But, awful as those impacts are, that’s about it. Studies by RERF and many others have found little other long-term health damage, even among the 54,000 hibakusha who were close to the explosions and were exposed to extraordinarily high levels of all sorts of radiation. (Ionizing radiation comes in various sorts of radioactive bits and energy waves, each of which has a different penetrating power and thus, danger.) Not even genetic damage. “Thus far, no evidence of increased genetic effects has been found,” the RERF scientists say.
The World Health Organization estimates of the health effects from Chernobyl rest on what those atomic blasts in 1945 taught us. Based on a meta analysis of the epidemiological research done post-Chernobyl, the WHO says that of several hundred thousand people exposed to potentially dangerous levels of ionizing radiation, over the entire lifetime of that population, roughly 4,000 might die prematurely from cancer caused by the radiation. http://www.who.int/mediacentre/news/releases/2005/pr38/en/index.html
Again, tragic. But again, a smaller number than many people assume.
But there are other reasons why nuclear radiation is scary. It’s invisible, which makes us feel like we can’t protect ourselves, and a lack of control contributes to fear. It causes cancer, a particularly painful end result, and the more pain and suffering something causes the more afraid of it we are likely to be. It’s human-made, and that makes it scarier than natural radiation risks, like the sun (which kills an estimated 8,500 Americans per year from skin cancer. www.cancer.org/downloads/STT/500809web.pdf).
Atomic bombings, and events like Chernobyl, are large scale and sudden, and catastrophic events tend to freak us out more than chronic killers, like skin cancer, or the air pollution from burning fossil fuels, estimated to cause tens of thousands of deaths each year in the U.S., 3 million globally according to the WHO.) The huge amount of attention these catastrophic events receive - rightfully - tends to burn the fear deep into our memories, raising our sensitivity to any similar risks when they come along.
Risk is subjective, a matter of both the facts and our feelings. Despite the evidence from the hibakusha and Chernobyl, nuclear energy scares many people, who resist it as one of the solutions to climate change, or a low emission way to reduce local air pollution. Their questions - “What about another Chernobyl or Three Mile Island,” “What about terrorist attacks on nuclear plants near big cities,” “What about the waste?” are all fair concerns that must be addressed. But, as we have learned from the experience of Mr. Yamaguchi and his fellow hibakusha, we should also honestly look to what science can tell us about this risk, or any risk, and keep the actual level of danger in mind as we weigh what to be afraid of and just how afraid we need to be. Otherwise the choices we make, both as individuals and as a society, may feel good, but may actually make things worse, not better.