Radiation and Reason

If we believe the headlines, it almost seems as if Japan was rocked by nuclear explosions, not by an earthquake. But our fears of radiation are overblown. Correctly understood, the dangers from nuclear fission are limited and manageable. The debate must be dominated by scientific facts, not by irrational concerns.

Tens of thousands have died in the Japanese tsunami and the survivors are cold and hungry. Meanwhile, world opinion is enthralled by a radiation panic. Yet the fear that nuclear radiation evokes is misplaced. Although several nuclear reactors are in ruins, radiation fatal casualties are nil and likely to stay so. Nuclear technology cures countless cancer patients every day – a radiation dose given for radiotherapy in hospital is no different in principle to a dose received in the environment. What of Three Mile Island? There were no known deaths there. And Chernobyl? The latest UN report published on 28 February confirms the known death toll – 28 fatalities among emergency workers, plus 15 fatal cases of child thyroid cancer – which would have been avoided if iodine tablets had been given out (as now in Japan). And in each case the numbers are minute compared with the 3800 deaths at Bhopal.

Imagined dangers

Records suggest that nuclear radiation is much less dangerous than most people imagine. So, we should ask the question, actually how dangerous is it? In the Cold War era people were taught that nuclear radiation presented a quite exceptional danger and that to understand it you must access a no-go area open only to “experts”. To cope with the “friendly fire” of this nuclear propaganda ever tighter radiation regulations were enacted to keep exposures “As Low As Reasonably Achievable” in an attempt to reassure people. International safety regulations today, based on this ideal, are set at a rate 1 milli-sievert per year.

We do not consciously sense nuclear radiation, and that increases feelings of apprehension. But what was not known in the early days is that cells of our body replace and mend themselves in various ways to recover from the damage that radiation causes. These clever mechanisms kick in within hours of a radiation dose and have been studied in radiobiology experiments in test tubes and with small laboratory animals. Most of the workers at Chernobyl who received a single dose in excess of 4,000 milli-sievert died in a few weeks, but patients receiving a course of radiotherapy usually get a dose of more than 20,000 milli-sievert to vital healthy tissue close to the treated tumour. This tissue survives because the treatment is spread over many days during which cells have time for repair or replacement. In this way many patients get to enjoy further rewarding years of life, even after many vital organs have received the equivalent of more than 20,000 years’ dose at the above annual environmental safety limit – which makes this limit unreasonable.

As high as relatively safe

A sea-change is needed in our attitude to radiation, starting with education and public knowledge. Then fresh safety standards are needed, based, not on how radiation can be excluded from our lives, but on how much we can receive without harm – mindful of the other dangers that beset us. Perhaps the acronym should be AHARS, As High As Relatively Safe. Radioactive waste is nasty but the quantity is small and it should be re-processed. Anyway it is not the intractable problem that many suppose. Would I accept it if buried 100 metres under my house? Yes, why not?

Modern reactors are better designed than those at Fukushima; tomorrow’s may be better still but we should not wait. More generally we should stop running away from radiation.

Wade Allison’s current book is Radiation and Reason: The Impact of Science on a Culture of Fear.

Read more in this debate: Ralph Martin, Cornelius Adebahr.


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