A scientific and responsible view of a nuclear threat in war

In the past few days irresponsible stories about nuclear radiation risks in the Ukraine-Russia War have appeared in the media, despite being firmly rebuked. In times of war misinformation can be dangerous and the subject deserves a wider discussion. It is a long time since the world received serious threats that included the words “nuclear” and “radiation”. How much weight should we attach to them? The science has changed since the Cold War, even though much of the same rhetoric is trotted out. Today the threat of a nuclear blast remains as serious as before, but we can be more relaxed about radiation. The simple facts of how life has evolved to survive nuclear radiation should increase our fortitude when threatened.

For more than 70 years nations have learnt to flinch and look away, confident that a rational enemy would do likewise. Mutually Assured Destruction, as the argument is named, was intended to provide a relatively stable solution. But Vladimir Putin seems undeterred by the possibility of self-destruction. It is time to face some simple questions about the danger of nuclear weapons – questions for which far better answers are available today than was the case decades ago. Then, the fear of nuclear explosions was the effective weapon. But what about the effect of an explosion that actually happens? It has two parts – first the blast and fire, and then the radiation and its consequences.

The energy is huge, a million times that of a similar weight of high explosive, and the blast and firestorm created are destructive over several square miles. Great as it is, this impact is immediate and local. It is over quickly and does not spread any further.

But it is the radiation that causes exceptional concern –long lasting and spreading worldwide, unlike the blast and fire. Despite being supported at the time by Albert Einstein, Bertrand Russell, Linus Pauling and other Nobel Laureates, the anti-nuclear protestors of the 20th Century were wrong about radiation. They did not have the evidence that we do today.

When Linus Pauling who wrote to President Kennedy in 1962, warning him against nuclear tests that “would seriously damage over 20 million unborn children”. He was concerned that radiation might cause inheritable biological defects in humans – and many others were equally concerned. But today we have the evidence from half a century of medical records for the hundred thousand survivors of the bombing of Hiroshima and Nagasaki and their descendants. With the support also of many decades of medical research this evidence confirms that such inheritable damage to humans does not occur. This is widely accepted.

Another concern has been cancer, although it is now known that radiation is a rather ineffective carcinogen. For instance, the number of survivors of the bombing who died of cancer, including leukaemia, over the following 50 years as a result of radiation was less than half a percent of those who died in the initial blast and fire. Evidently the blast and fire are hundreds of times more significant.

Why were intelligent people so concerned about radiation in the 1950s?

The advent of nuclear weapons should be seen in perspective. In military or political affairs, a modest change in resources can make the difference between victory and defeat. But nuclear energy offered a step change by a factor of a million – enough to bowl over normal political judgement. That is perhaps why, for decades after World War II, neither many of the scientists involved nor the public at large trusted national leaders to handle such power responsibly. In many countries around the world for many years domestic law and order was regularly challenged by vociferous anti-nuclear demonstrations driven by genuine fear and distrust. The authorities, unsure how to respond, banded together and sought to absolve themselves, taking refuge behind international standards set up for the purpose. These included bans on using or testing nuclear weapons, and recommended strict safety regulations set to precautionary levels, several hundred to a thousand times tighter than justifiable on any medical evidence of harm. Overseen by an international web of experts under the aegis of the United Nations, these were to maintain public reassurance – but such misjudged measures also excited unnecessary concerns.

Life on Earth has evolved in an environment where radiation is always present. It learnt long ago to cope with small and moderate exposures – otherwise we should not be here today. The effects of radiation do not accumulate, and radioactivity once dispersed is harmless, even if still measurable. So, a radioactive cloud following a nuclear explosion quickly fades in importance. Concern should be reserved for the blast and fire – and the bellicose policy that led to it.

The fear of radiation and the imposition of precautionary safety regulations have had serious consequences that continue to frustrate a beneficial future for humanity. In particular, the choice of primary energy to power society lies between:

sources refreshed daily by sunshine that proved too unreliable before the Industrial Revolution;
fossil fuels, found to be reliable with 1000 times more energy, but now seen as having an unacceptable effect on the environment;
nuclear energy, found to be reliable with a million times more energy again, negligible environmental impact and a better safety record.

But for the fear of nuclear and its radiation, the choice could have been settled for civil nuclear decades ago, as indeed it was in France. However, the fear of nuclear persists. The absence of any radiation casualties at the nuclear accident at Fukushima in 2011 seems to go unremarked, although the psychological, social and environmental damage caused by ignorance and media hysteria was severe. Further ill-advised decisions on energy policy then followed in Germany and elsewhere.

Fortunately for personal health, the extensive use of radiation in clinical medicine is accepted, as it has been since the work of Marie Curie. The world would be safer and more prosperous if there were a similar relaxed acceptance of radiation and nuclear technology in the public environment. This simple message is illustrated by a recent video of the wildlife in the evacuation zone at Chernobyl. Life there is flourishing, better for the absence of humans and despite the radioactivity.

While it is sensible to be deeply concerned by the blast and fire of a nuclear weapon, we need have no extra apprehension for the radiation. Media hysteria should be avoided, and we should learn the right level of respect for radiation, as we do for fire. Both are elements of the natural world that should be explained and discussed openly.

8 March 2022

Wade Allison
Emeritus Professor of Physics
Keble College, Oxford University
wade.allison@physics.ox.ac.uk