One thing is very obvious from Fukushima. The evacuations have killed more people than the radiation ever will. Recent scary articles notwithstanding, the number of cancers that will result from Fukushima-emitted radiation will be so few that they will not be detectable. That has not stopped some people from using computer models to predict radiation deaths half-way around the world and 50 years into the future.
The latest fear-mongering to surface around Fukushima was cited in
This is all about statistics. They use a statistical model of radiation effects, a statistical model of atmospheric effects, and a statistical model of dispersion to show that there is a statistically insignificant effect. Of course, the authors, Hoeve and Jacobson, don’t put it that way. They state that this number is non-trivial. But the number of cancers that would occur in the present 127 million Japanese population over their lives in the absence of Fukushima radiation is about (BEIR VII):
52,000,000 ± 50,000.
Assuming their calculations are correct, and their assertion that they all occur in Japan is correct, then in the presence of Fukushima radiation this number becomes:
52,000,130 ± 50,000.
This difference is less than trivial, it is statistically zero.
This fear-mongering comes down yet again to the Linear No-Threshold dose hypothesis, or LNT. As has been discussed before, LNT supposes that all radiation is deadly and that there is no dose below which harmful effects will not occur (BEIR VII) . While LNT has been hotly debated for over 50 years, everyone in the field agrees that the effects of low-dose radiation are so small that it cannot be seen in the overall population. The International Commission on Radiological Protection (ICRP), long a promulgator of LNT, finally admitted in its Publication 103 (2007) that “Collective effective dose is not intended as a tool for epidemiological risk assessment, and it is inappropriate to use it in risk projections.” But this is just what ideologues like Jacobson keep doing.
Of real importance is that the evacuation killed more people than the radiation ever will, even using Hoeve and Jacobson’s numbers. According to the The Daily Yomiuri, at least 573 people have died during the evacuation of the area around the Fukushima plants. And since many were evacuated from areas that were not contaminated enough to cause any health issues, this continued fear-mongering borders on being criminal. It distracts from the real suffering caused by the tsunami and the fear from the meltdown. Yes, there are contaminated areas that have to be cleaned up. Yes, Tepco and the Japanese government failed to heed the serious critiques and suggestions that the world nuclear community has been telling them for many years. But residents were evacuated immediately, and they were told not to eat anything from the region for the few months afterwards while I-131 died away, averting the real danger to children that was the biggest problem from Chernobyl. As Hoeve and Jacobson show, the doses to the public from Cs-137 have been too low to cause significant, or even measurable, harm.
Finally, I object to the disingenuous choice of units. One of the biggest weapons in the mis-information arsenal is the unit. Hoeve and Jacobson use units of microBq/m3 in air. Micro – as in one-millionth of a Bq (itself 1/37 billionth of a Curie). This is odd since the EPA (EPA zonemap) shows that background radiation in indoor air in the U.S. is about 150 Bq/m3, or 150,000,000 microBq/m3 in Hoeve and Jacobson's scary large number units. The lowest background air levels on Earth, over the oceans, are 3,000,000 microBq/m3. Their whole world map should be red with these levels of naturally-occuring radiation. Instead, most of the radioactivity numbers they put in their graphs are much less than background. Even their scary red parts are barely up to background. And variations in background radiation across the Earth do not track with cancer (see graph for U.S.). So what is the point of this article? That statistics are fun and can be used to scare people? That we should be very, very afraid of the air we breathe because it could cause a theoretical effect we can’t even measure 50 years from now? That you now have an excuse to admit you never liked sushi?