I note a recent article in Opinion Online by Dr Helen Caldicott was linked to in the Is Our Future Nuclear? comments thread, and this subsequently generated a fair amount of heated discussion. The focal claim from Caldicott in this piece is that it is dangerous to live near to nuclear power plants (NPP), because they supposedly increase rates of leukemia.
My basic response to such a claim is quite simple, and I think useful, because it cuts through the somewhat arcane and context-laden epidemiological arguments. It’s this: The additional radiation exposure of those living in the vicinity of NPP is ~0.0002 millisieverts (mSv), versus a background level of 2 to 4 mSv (depending on where you live) — the latter due to everything from cosmic rays, to ground-derived radon emissions, to eating bananas (this last one gives you more radiation than the NPP). So that’s 1/15,000 of your total yearly dosage coming from the ambient levels produced by nuclear power (in the US). Living near a coal-fired power station would give you 100 to 300 times more radiation exposure, and even that is trivial and not the reason coal burning is damaging to your health.
So, here is an apparently straightforward intellectual challenge. Can proponents of such an argument as Caldicott’s explain how something which adds 0.007% to an existing effect (background radiation) is somehow critically important, when adding 100 to 300% (or more) to an effect by simply moving from a house built on sedimentary rocks to one built atop granite, or moving from the state of New York to Colorado, is irrelevant? More here. Remember, radiation is radiation (principally alpha particles [helium nuclei], beta particles [high-speed electrons], x-rays, gamma rays [high-energy electromagnetic radiation] and neutrons), whether it comes from exploding stars, naturally decaying heavy metal atoms, CAT scanners, fission reactors, bananas, granite boulders, whatever. There is no unique ‘signature’ to the radiation from NPP.
Indeed, the Caldicott argument reminds me of the one used by proponents of the theory that it’s the sun causing recent global warming. As I’ve pointed out here, for a solar explanation to work, you not only have to explain why a climate forcing agent would be exerting a directional effect on the climate system when it itself is NOT changing — you also have to explain how that stationary agent is also able to negate another climate forcing agent that IS changing. It’s basically the same deal with the claimed link between NPP and radiation — what’s ‘special’ about its radiation from the background, and how is its effect amplified when that of other sources is not? I’ve never yet seen an answer (even an unsatisfactory one!) — to either of the above critiques, grounded in Socratic logic as they are.
But getting back to some of the statistical detail, if you want to understand more about the epidemiology of radiation exposure, I find it hard to go past recommending the huge body of work on this subject compiled by Prof Bernard Cohen, who summarised it extremely well here: “How dangerous is radiation?”, “Risks of nuclear energy in perspective” and “Plutonium toxicity“. The other recent review you should definitely read is “Radiation: Facts, fallacies and phobias” by Prof David Wigg, a clinical radiobiologist at the University of Adelaide. This is a 5-page review article published in 2007 in the peer-reviewed journal Australasian Radiology, but it is available free online (see link) and was written quite deliberately for a general audience. Here is the abstract:
There is frequent debate in the media and the scientific published reports about the use of radiation for diagnosis and treatment, the benefits and risks of the nuclear industry, uranium mining and the storage of radioactive wastes. Driving this debate is increasing concern about reliance on fossil fuels for power generation for which alternatives are required. Unfortunately, there is generally a poor understanding of the relevant basic sciences compounded by widespread irrational fear of irradiation (radiation phobia). Radioactivity, with special reference to uranium and plutonium is simply described. How radiation affects tissues and the potential hazards to individuals and populations are explained. The origins of radiation phobia and its harmful consequences are examined. Whether we like it or not, Australia is heavily involved in the uranium industry by virtue of having one-third of the world’s known reserves, exports of which are worth approximately $470m annually. As this paper has been written as simply as possible, it may also be of interest to readers who may have had little scientific training. It may be downloaded from the web using references provided in this article. It is concluded that ignorance and fear are major impediments to rational debate on radiation issues.
And his conclusion:
Over the last 100 years or so, the growth in understanding of radiobiology, radiation physics and many scientific disciplines associated with the nature and effects of radiation have been profound and continues to proceed rapidly. One example is the demonstration of the relatively harmless effects at low doses, doses that are most likely to be of interest to the general population and radiation workers. Failure to adapt to this knowledge by institutions, including the media, has led to many unfortunate consequences, one of which is widespread radiation phobia and its effects.
Yet Helen Caldicott continues to perpetuate long-discredited myths, despite knowing full well that her extreme views are contrary to all relevant evidence. A good summary of her recalcitrance on the matters of science and evidence is provided here, in a series of exchanges — again, this is well worth reading. The conclusion from Dr Michael Baker was particularly apt:
Her book, Nuclear Madness, is so full of half truths and blatant lies that it is hard for a scientist to read. You will note that her references include very few peer reviewed scientific papers and when they do they frequently do not support her conclusions. I believe that she hopes the reader will not take the time or have the resources to look up the scientific papers. I would conclude by encouraging the people that read her book and papers to do just that.
Gee, now, what does that remind me of?