In preparation for Monday's Point of Inquiry--which is on nuclear power--I've been learning more about this issue. As a result, while I don't agree with Helen Caldicott, I do feel George Monbiot is being a tad too strident, and probably should have used more hedging. Basically, there's a reason why death estimates for Chernobyl vary widely. I find the explanation here, from Lisbeth Gronlund of the Union of Concerned Scientists, really helpful. The trick is that although the risk diminishes greatly as the amount of exposure decreases, there's assumed to be no absolutely safe dose of radiation. This creates a situation in which, with Chernobyl, you have vast populations exposed to a tiny but non-zero dose. If you then do the math you get a large number of cancers, some of which will be deadly--but it is not like you will ever be able to point to who the victims were. This does not provide a justification for Caldicott's nearly 1 million deaths--but Gronlund finds that "70,000 and 35,000 are reasonable estimates of the number of excess cancers and cancer deaths attributable to the accident." Read more here.