June 13, 2002



The Federation of American Scientists has set out to establish itself as the experts on these "dirty bombs." Their line is that the bombs are unlikely to cause damage, but even a small 10 lb explosive with a couple missing medical gauges strapped on could deny the United States its landmarks, even its cities, for decades. What they expect to achieve by this is a good question, but their approach seems alarmist.

Read through their report here. Sounds scary doesn't it? According to FAS, a one-foot tube or irradiation-plant cobalt blown up in Manhattan would force a permanent evacuation:

It would be decades before the city was inhabitable again, and demolition [of Manhattan! -ed.] might be necessary.

Which would all be impressive, until you work out the math. Citing the EPA Linear No Threshold model of cancer causation by radiation, they come up with vast swathes of urban America devastated by a suitcase bomb. But it's just not so. Here's the problem. The LNT model assumes that the relationship between cancer and radiation is, as the title implies, linear. Your risk of dying of cancer, it assumes, is 4 per 10,000 per rem (a unit of radiation) received. The average American lifetime radiation dose is about 27 rems, more or less. That means that, of the approximately 20 out of every 100 Americans who die of cancer, less than 5 per cent of those cancers was due to just natural radiation (the others being due to smoking, chemicals, spontaneous mutation, etc.). If you get one more rem than the next guy during your life, your personal chance of dying of cancer theoretically goes from x per cent to (x+0.0004)%.

(None of this is proven, of course. Scientists have never been able to determine any effects on an individual who received less than an additional 5 rems on top of normal background. It's even possible additional exposures of less than 5 rems may have some beneficial effects. The model is derived by taking the more or less linear relationship between radiation and death that one sees at 20 rems additional dose or more (ie, as seen in Hiroshima survivors), and extrapolating for microdoses. But never mind that for now.)

Each of those FAS maps shows three ovals, showing the increased rate of death due to cancer, equating to 1 in 100 extra cancer deaths, 1 in 1,000, and 1 in 10,000. They don't apparently account for any attempts at remediation (ie, sandblasting buildings, removing soil, etc.) and appear to be calculated on whole lifetime risk (ie, if you lived within that given circle one's whole life). Based on the LNT model, we can calculate they equate to 0.5 rem, 0.05 rem, and 0.005 rem per annum additional radiation exposure. (In the first one, for instance, the largest circle, encompassing the entire U.S. Capitol area, would be the 0.005 rem per annum circle.)

Here are those numbers, thrown into a little context:

Outer circle +0.005 rem/year
Living in a brick house +0.007 rem/year
EPA standards for Yucca Mtn +0.015 rem/year
Living in Denver +0.025 rem/year
Middle circle +0.05 rem/year
Maximum allowed normal workplace exposure +0.1 rem/year
Living on Bikini Atoll +0.3 rem/year
Inner circle +0.5 rem/year
Maximum nuclear worker workplace exposure +2 rem/year (Canadian); +5 rem/year (American)

Now, I know we're all scared of radiation around here, but if in the FAS's worst possible scenario, where Manhattan is irradiated, even without remediation of any kind, the city ends up only as radioactive as Bikini today (where you are allowed to live now, you just can't eat any food that's grown there), I'd suggest the demolition of the city may not be necessary (you could even be allowed to work, but not live downtown, wear radiation badges etc., and do other things to limit your exposure, which would be hell, but not the end of New York as we know it.) As for their two less-than-worst scenarios (ie the more likely ones), as one can see the 0.5 rem/year oval (to my mind, the only one that really would force significant dislocation) is less than a city block. If your terrorist places his explosive carefully, he could deny the American public access to about one major landmark with each of these smaller-type bombs that he has, which only require fairly small and common radioactive sources -- the kind he could get from breaking into hospitals, etc. -- but that's about it. But forcing the mass evacuation of city cores would require more significant quantities of radioactive material. That suggests that we don't need to panic just yet about the sort of minor radiation sources found in medicine, oil drilling, etc., so much as the significantly larger ones found in food irradiation and the nuclear industries. Indeed, a strategy of increased security on this relatively small number of domestic points of theft, combined with radiation security on border entry points, could be sufficient to avoid catastrophic results from "dirty bombs."

(One should add at this point that there is no way of knowing whether any given fatal cancer was caused by radiation, or by any number of other causes. Other than the LNT model, there is not even any evidence that x per cent of human deaths are due to natural background radiation... a number that would at worst only double even among any population that chose to live, eat, sleep and die in a thoroughly Irradiated Manhattan. Among the at least 20 times as many non-radiation-induced cancers in that population, those deaths would still be just statistical noise.)

NB: Yes, you read right. If you live in brick houses your entire life, due to the increase in natural background radiation your chance of dying of cancer increases by about 0.015 per cent over what it would be otherwise, according to the LNT model. Feel free to amend your homebuying choices accordingly.

NB#2: It bears repeating here that, as one can deduce from above, the risk of a radiological weapon (assuming you're not in the immediate, flying debris blast area) is slow-acting. There will no doubt be radiological weapon threats in our lifetime, both true and hoax. The real lesson these numbers tell is that, unlike say, an anthrax attack, you don't need to panic, or push the old lady down the stairs to evacuate the downtown when you hear about one on the radio. Your chance of survival is probably improved by taking a couple hours or days to put your affairs in order before trying to leave any lightly contaminated area in such an instance. So take it easy, listen to what the cops tell you, and don't start running down the street screaming, for pete's sake. If there was a radiological weapon threat in Toronto right now, I'd still take the subway home... and sleep in my bed tonight, too.

Posted by BruceR at 03:40 PM



My recent close involvement with Warblogger Watch has its upsides, like an introduction to some writers I haven't read before, such as John and Antonio. They have a nice essay on jingoism here, which I'd love to agree with if it wasn't for their complete dismissal of the "useless death" of World War One:

[A war] fought over nothing important in particular and which wiped out a whole generation of the best, fittest European young men...

Now, I've read and appreciated revisionists like Niall Ferguson, too, but I still have to say that, by the point at which Britain (and Canada) had to choose whether to get involved in the widening war, it wasn't being fought over "nothing important" any longer. Germany HAD invaded a neutral Belgium. Britain had promised Belgium it would intercede. If resisting the subjugation of neutrals and honoring one's treaty commitments are to be seen as "nothing important," then there is very little reason any country should ever go to war... as the bad guys in the international system would then effectively have complete carte blanche (If you want to question whether Russia should have activated the grand alliances and thrown the world into war by intervening in yet another Austro-Serbian border spat, well, that's a whole other argument, though.)

I would add that the implicit assumption that all the (presumably Western Allied) combatants in the Second War fought with a sense of righteous purpose, and that their counterparts in the First fought with nothing but a sense of futility (the reasoning behind the writers' dismissal of novels about the Second World War like Catch-22 as being inferior to Remarque et al,) is not based in good history. See again Ferguson, and his collection of accounts of soldiers writing from the Flanders trenches who were actually enjoying themselves immensely.

If nothing else, one would expect the writers, who go on to praise the current conflict for our lack of impact on Afghan civilians, would recognize that in that particular respect, the First World War (with reasonably fixed battlelines and safe rear areas) was far superior to the total war of the Second.

Posted by BruceR at 10:52 AM



TNR's got the goods. At some point, Americans are going to wake up and realize that their government has created a New Bastille, rounding and locking up increasing numbers of alleged terrorists for indefinite confinement without charge or trial. (Trouble is, they can't really reverse course on Padilla now without raising questions about the even larger injustice of Guantanamo. So they probably won't.)

UPDATE: The Post does an even better job:

The question is not whether the government can detain an enemy combatant bent on doing America great harm but whether it can designate anyone it chooses as such a person without meaningful review... the government refused to let [second American Taliban Yaser] Hamdi meet with a federal public defender interested in representing him. And when that lawyer sought to file a case on his behalf anyway, the government then contended in a Kafkaesque twist that, having had no prior relationship with Mr. Hamdi, the lawyer could not do so.

The idea of indefinite detentions of Americans who have not been convicted of any crime is alarming under any circumstances. Without the meaningful supervision of the courts, it is a dangerous overreach of presidential power. If such a thing were happening in any other country, Americans would know exactly what to call it.

Posted by BruceR at 10:11 AM