The Denver Dose

“In hindsight, it is hard to resist the conclusion that the policies enacted in the wake of the disaster in Japan—particularly the long-term evacuation of large areas and the virtual termination of the Japanese nuclear power industry—were expressions of panic.”

The tens of thousands dead from the earthquake and tsunami go unnoticed while radiation fears continue to get headlines. Richard Muller describes the Panic Over Fukushima.

“The most thoughtful high-number estimate of deaths that will be caused by the Fukushima disaster comes from Richard Garwin, a renowned nuclear expert. He has written that the best estimate for the number of deaths is about 1,500—well above my estimate but still only 10% of the immediate tsunami deaths. … he ignores the sort of argument that I have made about the Denver dose and includes in the calculation the numbers of deaths expected from tiny doses, assuming that even small exposures are proportionately dangerous. (This is an assumption that has also been adopted by the U.S. National Academy of Sciences.)”

The Denver Dose is the natural background radiation in Denver, Colorado. The background radiation depends upon altitude and the nature of the rocks in an area. Consideration of the radiation dosage that people get living in such areas to those in other areas is one of the factors in the debate about radiation hormesis. Current standards are based on the theory that risk is related to dose all the way down to zero. Background radiation considerations and other data indicate that low dosages may not present a risk or may even provide a benefit (which is what the hormesis theory is all about).

“The International Commission on Radiological Protection recommends evacuation of a locality whenever the excess radiation dose exceeds .1 rem per year. But that’s one-third of what I call the “Denver dose.” Applied strictly, the ICRP standard would seem to require the immediate evacuation of Denver. … There is a strong argument for ignoring radiation dangers below the level of the Denver dose. In doing so, we would be ignoring risks that are unobservable and which we routinely ignore (and properly so) in other circumstances.”

So Japan is shutting down its nuclear power industry because of fear of risks that are so small as to buried in the noise. The geological disaster caused 15,000 or more casualties while the nuclear plant problems might cause only 0.1% of that over the long term and in a way that will be difficult to tell from normal disease rates in the population. What is not considered in the comparison is just how many deaths might be caused by the shortage of electrical power as the nuclear plants are shut down. That risk, too, the risk from reduced power availability and consumption, is difficult to asses but a risk as real and as significant – or more significant – than the long term radiation exposures on the level one finds as normal background radiation in various parts of the planet.

Comments are closed.