Forget the Cold War propaganda – David Bird took a serious look at the worst part of nuclear weapons, the slow, painful death from radiation to answer the question: Yes, but what about the cockroaches?

David Bird

Growing up in the Cold War we knew that any day could end with our utter destruction and the loss of everything we hold dear. The only survivors? Those lowly cockroaches we so despise. As images go, it brought home the wastefulness of our prevailing strategy, Mutually Assured Destruction - but was it true? Would the little garbage eaters really survive when we couldn’t?

Neither of us would survive the fireball at the center of the explosion, but most of the victims of a nuclear bomb wouldn’t be at the center anyway. They would die painfully over the next several days, poisoned by the radioactive fallout. Actual experience in these matters is blessedly little. Only two bombs have ever been used against humans and then no one thought to consider the cockroaches of Hiroshima and Nagasaki. So we have to take stock of what we know about the effects of radiation and, while we know quite a bit, it is surprising how little has made its way out of academic circles and into public discussion.

One problem compounding discussion is the terminology. Information is given in rads and grays, in roentgens and coulombs. Rads and roentgens are older terminology that has been replaced by grays and coulombs. For this article it is rads and grays that are important. They are measurements of doses of absorbed radiation, but they aren’t equivalent units of measurement. Four hundred rads, for example, is not the same as four hundred grays. The Powers That Be are both calling for the consistent use of the new system and allowing the older, more familiar, terms to continue. For my purposes I am sticking to sources that use rads. There are simply more of them. A second problem is that the amount of radiation necessary to kill someone isn’t consistent from one person to the next. Four hundred rads are enough to kill someone, but people have survived up to a thousand rads. The length and extent of exposure are both important factors in calculating a lethal dosage. Consequently, these numbers should be understood as averages, or as the typical amount necessary, and not as an absolute threshold.

Radiation is dangerous because it breaks down the transmission of DNA from cell to cell and in doing so prevents proper cell regeneration. That’s simplistic, yes, but it’s the basic problem in a nutshell. Our cells are regenerating all the time and so a dose of radiation can have a serious and immediate impact on our health and safety. But this isn’t true of all animals. Animals with exoskeletons grow in stages. They shed, of molt, their exterior casing when they are ready for another growth period. This is the primary reason why cockroaches stand a better chance of surviving a nuclear attack than we do. Cockroaches can survive up to 6400 rads of radiation. When compared that to the 400 to 1000 rads that would kill one of us, it would appear that cockroaches start with a definite advantage.

But how many rads would a nuclear explosion unleash? Hiroshima was approximately 1200. Enough to kill us, but not enough to kill a cockroach. On paper, anyway. Actually, almost half the population of Hiroshima was neither injured nor killed by the bomb. Many factors besides raw power, go into the effectiveness of any weapon, including a nuclear one. The higher the altitude at which it explodes, for example, the wider the range of the damage it will inflict. And since the Second World War the bombs have become a lot more powerful. The bomb dropped on Hiroshima had the equivalent destructive force as 15 kilotons of TNT. The most powerful nuclear weapon tested was the Soviet Tsar Bomba, which had a force of 50,000 kilotons of TNT. Enough to kill us and the cockroaches.

But most bombs, while still far more powerful than Hiroshima, aren’t up to that Soviet record. Various scenarios have shown that their effects, while catastrophic, would not destroy all human life. If a 150 kiloton bomb were, for example, to explode in Manhattan1 (noon at the foot of the Empire State building) 75,000 people would instantly die. Most of the people within a mile of the explosion would be killed and no one would escape injury. But broaden the radius to four miles and less than half the population would be killed or injured. But this is the immediate impact of the explosion. If a nuclear war was fought and multiple cities were destroyed, the nation’s – indeed, the international – infrastructure would be destroyed. Imagine Katrina on a global scale, with no one outside the disaster zone to help. Starvation and disease would kill many, many survivors. And if it were to happen in winter, the cold would compound the problem even further.

And the cockroaches? Given their greater resistance to radiation, their survival rate should be higher, but one question that no one has addressed is: how well would the cockroach population survive the general destruction of its primary food source: us. Like rats and gulls, the cockroach has been a beneficiary of our extraordinary ability to produce far more than we need. We build up mountains of waste. The cockroach is a hardy creature. It can live a month without its head. But the destruction of our infrastructure will mean the destruction of its infrastructure as well. Now, there are 4500 kinds of cockroaches and they have been around 300 million years. The decimation of our numbers won’t mean their destruction, but it’s unlikely that they will flourish. They will survive in great numbers, greater numbers than ourselves, but the likelihood that they would supplant us is largely a rhetorical device. There are actually many insects that are far more resistant to radiation than the cockroach. The fruit fly is ten times more resistant. But the image of fruit flies circling irradiated bananas doesn’t instil the same sense of waste and disgust as a world dominated by the cockroach. And that really was the point of this cold war metaphor. Sure we have the power to destroy everything, but what is the value of a ‘power’ that reduces everything to garbage?

1 For more on the New York scenario, see here:
http://www.atomicarchive.com/Example/index.shtml

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