Friday, January 25, 2013

Are You Prepared for a Nuclear Detonation?

I'm not. And I doubt more than a handful of people in the US are. And I'm not sure whether that's a good thing or not. On the one hand, I don't want to be alarmist. On the other, If we as a nation value our nuclear weapons so highly that we won't get rid of them, can we reasonably expect that nobody will ever try to use them against us?

When the debate about the Seabrook nuclear power plant was happening, I was of an impressionable age. I lived in Amherst, New Hampshire, and Groton, Massachusetts, just across the border from one another. The gym at my school was labelled as a "fallout shelter" and looked like a bunker. I read a few books about the Manhattan Project and its terrible debut in Hiroshima. I was fascinated by the science and the scientists, and also by the majestic horror that they unleashed. I had dreams about running to that shelter and what might happen as we waited days and weeks for help to arrive.

Unlike people a few years older than me, I had never undergone a 'duck and cover' drill. By that point, they were mocked as silly - inducing unnecessary nightmares in our youth - not to mention useless in the face of a bomb capable of incinerating an entire city. I took some comfort in the fact that Fort Devens was in the next town over. In the event of an all-out exchange, I prayed we wouldn't have a chance of survival.

And yet, we as a nation still maintain an enormous arsenal of nuclear weapons, and devote considerable resources to them. Why? I'll leave that to others for the moment. A great discussion can be found on KQED's Forum here.

Although it has gone out of fashion to speculate about nuclear weapons use, I would argue that it is foolish to be as ill-prepared for it as we are. Unlike the nightmares of my youth, the prospect of an all-out exchange between the US and the Soviet Union has passed. The prospect of an all-out exchange between the US and any current nation is exceedingly remote.But with all the crazy people in this world, the more likely scenario is that someone, somewhere, will be able to put late-1930's technology together with evil intent to deliver a rudimentary nuclear weapon to our doorstep.

A Dirty Little Secret
Nuclear weapons are more survivable than we imagine. The 'duck and cover' drills of the 1950's and 1960's may have indeed been silly. But I suspect that the real reason they went out of fashion isn't because they were futile, or terrifying, but because continuing them made the idea of using nuclear weapons seem plausible. By preparing for nuclear war, we were countenancing the possibility that it might happen, and nobody wanted that. In that light, I want to be clear that claiming nuclear weapons are more survivable than we imagine should in no way make them easier to use.
In college, I read about an epidemiologic follow-up of survivors of the atomic bombings of Hiroshima and Nagasaki, to trace the longer term effects of nuclear weapons exposure (and from a more cynical perspective, to help set regulatory guidelines as to acceptable levels of x-ray exposures in the US). When I taught my epi classes at SFSU, I incorporated this article into teaching about cohort study design.
One thing that was shocking about this study was how many survivors there were. I don't in any way want to minimize the number of deaths, but it was shocking to me to learn that some people who were within 1 kilometer of the blast center survived, and relatively few people 10 kilometers away from the centers of the blasts were killed. Not only that, but the study treated these people beyond 10 kilometers as the 'unexposed cohort' - that the radiation dose one received from the initial blast at a distance of 10 kilometers was not much higher than background. Or in other words, if a Hiroshima-sized bomb went off over the Transamerica building in downtown San Francisco, we in our classroom at SFSU would be considered 'unexposed' in that study design.

Back during the debate about opening the Seabrook plant, there was a lot of scare-mongering using mushroom clouds to illustrate the risk of a nuclear meltdown. But a nuclear power plant can't explode, so I think that hyperbolic representation may have really undercut the cause. What nuclear weapons do share with nuclear power plants in terms of risk is fallout. That is, a nuclear power plant is not going to blow up and cause the explosive damage of a bomb, but both a bomb and a plant have the potential to release a lot of fine dust particles carrying radioactive elements over a relatively wide area. That's the scary part.

The hopeful part is that with a bit of preparation, you can offer yourself a great deal of protection from the fallout. First, close your windows and seal them up with plastic. I know, it sounds silly, but the biggest danger fallout presents is if you breathe it in or swallow it. Your skin is pretty good at dealing with two types of radiation (alpha and beta), but your lungs and stomach are very susceptible. That's because we are constantly bombarded with radiation from the sun, so we've evolved pretty good external defenses. The third type of radiation, gamma radiation, gets less harmful the farther you are away from it. As an analogy, if you hold a light bulb up to your face, it is blinding.  In the ceiling, it provides a nice glow, but the light from that bulb is practically useless if you are out in the driveway hunting for a dropped wallet.
So, making your home as air tight as possible makes it harder to breathe in or swallow fallout particles, and by keeping them outside the home, it keeps you farther from the gamma radiation.
Similarly, you want to stay in the middle of the house, away from ground level (where the fallout settles), but also not too near the roof (because it falls there too). And, if you can surround yourself with stuff, even better, because stuff absorbs radiation. Water is a great radiation-absorber, but books, even blankets, will help a little bit. You got a water bed? Awesome place to crash.
You may think that hunkering down in the center of your plastic-wrapped house, surrounded by buckets of water may not be the ideal way to spend the rest of your life, and you'd be right. But there is a saving grace - called "half-life". Radioactive atoms can release radiation at any moment, but on average, half of them will "go off" within a set amount of time. And because a lot of radioactive fallout elements have a short half-life, it is estimated that the danger of fall-out is reduced about 90% within 3 days, and well over 99% within 3 weeks. So, even after only three days of hunkering down, the risks from fallout are considerably lower.

The other thing you'll want to do is pray for rain. Rain is really effective at pulling any remaining fall-out out of the air (so it will be harder to breathe it in), and also does a decent job at washing the radioactive dust off your roof, off the sidewalk, and either into the sewer, or down into the ground a bit. And fallout in the ground is a lot less dangerous than fallout on the ground (imagine taking an x-ray with even a quarter-inch of soil between you and the camera). At that point, the major concern would be from radioactive elements (like iodine-131) that get absorbed from the ground into crops that you (or your cows) eat.

Hope that helps you sleep better tonight....