OVER the last fortnight I have made a deeply troubling discovery. The anti-nuclear movement to which I once belonged has misled the world about the impacts of radiation on human health. The claims we have made are ungrounded in science, unsupportable when challenged, and wildly wrong. We have done other people, and ourselves, a terrible disservice.

I began to see the extent of the problem after a debate last week with Helen Caldicott. Dr Caldicott is the world’s foremost anti-nuclear campaigner. She has received 21 honorary degrees and scores of awards, and was nominated for a Nobel peace prize. Like other greens, I was in awe of her. In the debate she made some striking statements about the dangers of radiation. So I did what anyone faced with questionable scientific claims should do: I asked for the sources. Caldicott’s response has profoundly shaken me.

First she sent me nine documents: newspaper articles, press releases and an advertisement. None were scientific publications; none contained sources for the claims she had made. But one of the press releases referred to a report by the US National Academy of Sciences, which she urged me to read. I have now done so — all 423 pages. It supports none of the statements I questioned; in fact it strongly contradicts her claims about the health effects of radiation.

I pressed her further and she gave me a series of answers that made my heart sink — in most cases they referred to publications which had little or no scientific standing, which did not support her claims or which contradicted them. (I have posted our correspondence, and my sources, on my website: www.monbiot.com) I have just read her book Nuclear Power Is Not the Answer. The scarcity of references to scientific papers and the abundance of unsourced claims it contains amaze me.

For the last 25 years anti-nuclear campaigners have been racking up the figures for deaths and diseases caused by the Chernobyl disaster, and parading deformed babies like a mediaeval circus. They now claim 985,000 people have been killed by Chernobyl. These claims are false.

Here is what the UN Scientific Committee on the Effects of Atomic Radiation (Unscear) says about the impacts of Chernobyl.

Of the workers who tried to contain the emergency at Chernobyl, 134 suffered acute radiation syndrome; 28 died soon afterwards. Nineteen others died later, but generally not from diseases associated with radiation.

— The Guardian, London