On March 11 of 2011, the most powerful earthquake known to have hit Japan struck near the east coast of Honshu. The earthquake generated a tsunami that reached a height of more than 130 feet. Just last month, the Japanese National Police agency reported that there were at least 15,870 people who died, an additional 6,114 who were injured, and 2,814 who are still missing as a result.1 Obviously, it was a disaster of truly stunning proportions.
One of the many things that happened as a consequence of the disaster is that some of the reactors at the Fukushima Daiichi Nuclear Power Plant went into meltdown, and radioactive substances were leaked into the ocean and released into the air. People in a 12-mile radius around the power plant were evacuated so that they would not be exposed to too much radiation. As a result of the meltdown, there is increasing political pressure for Japan to end its reliance on nuclear power. According to the Christian Science Monitor, Prime Minister Yoshihiko’s party has recommended that Japan phase out all nuclear power by the year 2030.
Back when the nuclear disaster was in the news, I commented on it (here and here). Since then, I have been following the scientific literature to see what those who have been monitoring the situation are saying regarding its long-term effects. Recently, a study and some commentary on the study were published in the journal Energy & Environmental Science, and they are surprising, to say the least.
Let’s start with the study. John E. Ten Hoeve (a meteorologist) and Dr. Mark Z. Jacobson (an environmental engineer) looked at the latest figures regarding the identity and quantity of the radioactive material that was released. They then used those data in a global atmospheric model to produce an estimated map of the increased radiation exposure experienced around the world as a result of the meltdown. They compared their map to measurements of the actual exposure in several regions of Japan, and while there were some inconsistencies, I was surprised by the general amount of agreement between their map and the actual measurements. It’s not clear how accurate their map is the farther it gets from Japan, but for Japan itself, it seems that their map is a good guide for estimating the radiation exposure that resulted from the meltdown.
They then used that map in yet another model to predict the long-term health consequences that will result from the meltdown. Their study indicates that the meltdown will probably cause 15-1,100 additional deaths due to cancer. Their best estimate of the actual number of additional deaths is 130. In addition, they estimate that there will be 24-1,800 additional cases of cancer. Their best estimate of the actual number is 180.2 While their estimates cover the entire world, the vast majority of the additional cancer deaths and cancer cases will be in Japan.
Now of course, there are all sorts of reasons to be skeptical of these estimates. After all, they are based on two separate models, and only one of those models has been even marginally confirmed by actual data. Indeed, the estimated ranges of additional cancer deaths and additional cancer cases are so broad specifically because of the uncertainties in the models. However, for the sake of argument, let’s take their maximum numbers: 1,100 additional deaths and 1,800 additional cases of cancer worldwide. Those numbers sound really large, but they pale in comparison to the 15,870 who died and the 6,114 who were injured as a direct result of the earthquake and tsunami.
Here’s another way to look at the numbers. According to the authors:
Nearly 600 deaths were already certified as “disaster-related” by the 13 municipalities affected by the crisis at Fukushima. These deaths were caused indirectly by fatigue or aggravation of chronic illness due to the disaster, many of which can be attributed to the mandatory evacuation following the accident.
So even if the maximum number of additional deaths estimated by the study is correct, it might not even be twice the number of deaths that were caused by the evacuation!
Does this mean that the meltdown experienced at the Fukushima Daiichi Nuclear Power Plant was trivial? Of course not! Even if the study’s minimum numbers are correct, the resulting additional cancer deaths and cancer cases are still too many. Any numbers above zero would be too many. However, if Japan is going to craft a sane energy policy, these numbers have to be put in perspective. Indeed, that’s what Nobel Prize-winning physicist Dr. Burton Richter did in an opinion piece published in the same journal. He states:3
What struck me ﬁrst on reading the Ten Hoeve-Jacobson paper was how small the consequences of the radiation release from the Fukushima reactor accident are projected to be compared to the devastation wrought by the giant earthquake and tsunami.
He then did some calculations to estimate the number of hours of human life lost due to electrical power generation. According to his calculations, every terawatt hour of electrical power generated by a coal-burning plant causes a loss of 138 years of human life due to the pollutants that are released. Gas-burning power plants produce only 42 years of human life lost for every terawatt hour of electrical power generated, and nuclear power plants produce only 30 years of human life lost. Since Japan currently consumes about 280 terawatt hours of energy each year:
The obvious conclusion is that nuclear power is better for your health than other choices, a conclusion that may come as a surprise to many.
Of course, not everyone agrees with Dr. Richter. In fact, in a reply to his opinion piece, the authors of the study say that neither coal nor gas power plants are reasonable for Japan, and to put the matter into proper perspective, Dr. Richter should have considered alternative energy sources such as solar power and wind power. In addition, they say that to properly calculate such things, you also need to compare the deaths and illnesses associated with collecting the fuel and disposing of the byproducts. In the end, then, they were not very impressed by Dr. Richter’s analysis.4
Regardless of who is right on this point, I think that the study by Ten Hoeve and Dr. Jacobson tells us that the disaster associated with the Fukushima Daiichi Nuclear Power Plant will not have the long-term consequences that many feared. Even if their estimations are way off base, consider a point they bring up near the end of their study:
…total I-131 and Cs-137 radiation released from Fukushima is roughly an order of magnitude lower than the total radiation released from Chernobyl. In comparison, the total amount of I-131 and Cs-137 released from the Three Mile Island accident was 1/100,000 and 1/100,000,000,000 that of Fukushima, respectively, suggesting a total excess cancer burden of near zero associated with the Three Mile Island accident.
So if nothing else, we know that the Fukushima Daiichi Nuclear Power Plant disaster was not the worst in history. In fact, while it was significantly more disastrous than the Three Mile Island incident in the U.S., it was nearly ten times less disastrous than Chernobyl! Hopefully, this kind of perspective will be used by those who are making energy policy decisions in Japan and around the world.
3. Burton Richter, “Opinion on Worldwide health effects of the Fukushima Daiichi nuclear accident,” Energy & Environmental Science 5:8758-8759, 2012
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4. John E. Ten Hoeve and Mark Z. Jacobson, “Reply to the Opinion on Worldwide health effects of the Fukushima Daiichi nuclear accident,” Energy & Environmental Science 5:8760, 2012
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