GUEST WORDS--When we think about nuclear energy, what usually comes to mind are its worst consequences. The disastrous accidents of Chernobyl and Fukushima—as well as the atomic bombings of Hiroshima and Nagasaki—loom large in the debate over whether we should rely more heavily on nuclear power as part of a shift toward a low-carbon energy economy. But do these terrible events loom too large? In a recent piece in Genetics, biologist Bertrand Jordan, of Aix-Marseille University in France, argues that most of us have an exaggerated view of the dangers of radioactivity, and that this is distorting the debate over nuclear power as a viable clean energy option.
Jordan bases his argument on the results of long-term studies of Japanese atomic bombing survivors.
The atomic bombings of Hiroshima and Nagasaki were terrible human tragedies, but they were well-measured ones. In the weeks and years after the bombings, American and Japanese scientists assessed not only the physical injuries of the bombing victims, but also their level of exposure to radiation emitted by the bombs. These initial assessments grew into the world’s most important study of the health risks of radioactivity. Atomic bombing survivors of all ages and sexes, including some still in the womb, were exposed to different doses of radiation. Nearly 100,000 of them have been tracked over the subsequent six decades.
This large study, a joint United States-Japanese effort called the Life Span Study, has also followed 77,000 children born to bombing survivors, and it continues to this day. Results from this study are the primary basis for essentially all government regulations and guidelines on safe exposure to radiation, from limits on medical x-rays and CT scans to recommendations for airline flight crews, who, working at high altitudes, are exposed to more cosmic ray radiation from space.
What do the results of the Life Span Study show? Jordan argues that, as terrible as the atomic bombings were, there is “a very striking discrepancy between the facts and general beliefs” about the long-term effects of radiation on the bombing victims. Because we associate radiation with the awful power of nuclear weaponry (which threatened world destruction for half a century), or with disasters like Chernobyl, we tend to think that radiation is more harmful than it actually is. But if we look at the data of the Life Span Study, Jordan says, we find instead “measurable but limited detrimental health effects in survivors, and no detectable genetic effects in their offspring.”
Jordan first points to cancer rates among survivors, which are indeed elevated, but still relatively low. Cancer is one of the most feared effects of radiation: At a low to moderate dose, you can’t see or feel radiation, yet that can be enough to cause mutations that produce a deadly cancer decades later. But only a minority of atomic bomb survivors ever developed cancer — even among those who were exposed to higher levels of radiation. For example, among one set of about 45,000 survivors, there was a 10 percent increase in solid cancers (such as breast or stomach cancer) compared to an unexposed population. This equates to roughly 850 cases (out of 45,000 people) that can be attributed to atomic bomb radiation — tragic, to be sure, but, according to Jordan, much less common than most people would expect.
Furthermore, radiation had little impact on the life expectancy of survivors. At moderately high doses, the Life Span Study found a roughly one year reduction in life expectancy. At lower doses, this reduction was less than two months. This, Jordan notes, is much less than the effect of a major social disruption, like the one that took place in Russia after the end of the Cold War, where life expectancy decreased by five years between 1990 and 1994.
Finally, radiation from the atomic bombs does not appear to have affected the next generation. Harmful mutations caused by radiation can sometimes be passed on from parents to children, which means that, in theory, the effects of the bombs’ radiation could persist across a generation. But Jordan notes that, among the children of atomic bombing survivors, there is “no detectable radiation-related pathology.” Jordan acknowledges the important caveat that some of these children are still relatively young (in their 40s and 50s), and thus an increased risk of cancer among them may not be evident for another few decades.
Given these relatively small effects, Jordan argues that the “contradiction between the perceived (imagined) long-term health effects of the Hiroshima/Nagasaki bombs and the actual data [is] extremely striking.” He believes that the issue of nuclear energy is much like the issues of climate change or the safety of genetically modified foods, where public misunderstanding gets in the way of good policy solutions. It is therefore “important to try to clear up these questions, and to disseminate widely the scientific data when [it exists], in order to allow for a balanced debate and more rational decisions.”
Are our fears of radiation really preventing us from rationally considering an effective, no-emissions source of energy as part of our plans to curb greenhouse gases?
Probably not. It’s true that, if you survive an atomic bombing, you are still unlikely to develop cancer and your children will probably not be afflicted by genetic diseases. And major nuclear accidents are not common — there have only been five in the past 69 years. That’s certainly a much better track record than coal-fired plants, whose emissions affect the health of thousands of people in the U.S. every year.
Yet even rare nuclear accidents affect the lives of hundreds of thousands to millions of people. The reactor meltdown at the the Fukushima Daiichi nuclear power plant in 2011 ultimately led to the evacuation of about 170,000 people. Although nearby residents were exposed to only low levels of radiation, the accident caused an enormous disruption that measurably harmed residents’ mental health.
The explosion of the Chernobyl reactor in 1986 was even worse. The World Health Organization estimates that five million people currently live in areas contaminated with radioactive materials blown across Belarus, Russia, and Ukraine, after the explosion of the Chernobyl nuclear reactor. WHO researchers estimate that this single accident will ultimately cause up to 4,000 deaths, largely from cancers that develop decades later. And so, even if, as Jordan argues, the health risks of radiation aren’t quite as bad as most of us believe, the dangers of a nuclear accident are still considerable.
When you consider these very real dangers alongside other major issues associated with nuclear power — disposal of extremely hazardous waste, security from terrorist threats, and the generally unfavorable economics of nuclear power — it’s clear that nuclear energy faces bigger problems than our irrational fears.
(Mike White is Assistant Professor of Genetics at Washington University in St. Louis and is a contributing writer at Pacific Standard magazine … where this piece was first posted.)