Monday, October 29, 2007

Three Things, Including Isotopes

1. Happy birthday to my poor, neglected blog. It's one. I think it may be teething.

2. In honor of which (okay, not really) I am giving away a hat and scarf; see below. [Update: Taken by an intrepid reader.]

3. In keeping with The Internet Is Made of Clogged Tubes, we have a dispatch from the 'Chairman of Science and Technology Subcommittee on Investigations and Oversight', i.e. one Brad Miller.

Fearmongering the Nuclear Way

Recently on NPR:
The U.S. has a shortage of laboratories to test the thousands of people who might be exposed to radiation if a "dirty bomb" detonated in a major city, according to a recent congressional investigation... Should this happen in real life, the nation would not be able to quickly conduct tests for these people, because there are few labs capable of doing so in the country; and the tests available only address six of the 13 radiological isotopes that would likely be used in a dirty bomb.
Sounds alarming, doesn’t it? You could be contaminated with radiation! And it would take years to get tested! Oh no!

First of all, the government in the person of Brad Miller is being moronic. This problem has been studied in exhausting detail already, by the government, the WHO, the military, Brookhaven, and so on.

The government runs a whole testing facility to simulate ‘dirty’ bombs. It’s called Sandia. Last year, they published a paper entitled “Emergency Response Guidance for the First 48 hours after the outdoor detonation of an explosive radiological dispersal device.’ (Health Physics, April 2006 90:4, Musolino and Harper.)

Quick! A bomb just went off in Downtown Your City. By extraordinary chance, your Geiger counter was pointed out the window and it's screaming. What do you do? You get the hell away from the explosion, that’s what you do. Do you need to be tested immediately for radiation in your blood, as only a few labs can do? No. You need a building to not fall on you.

As emergency responders who suspect a dirty bomb, this is what you do: evacuate the area, set up a perimeter outside the dangerously radioactive area, and make sure you’re upwind. If a large number of people have been exposed- say the experts- they’re going to evacuate themselves anyways, so set up some roadblocks to direct traffic away from the bad bits.

For most people outside the ‘high zone’, nearest the explosion, assume they didn’t get a dangerous acute exposure. Tell them to go home, put their clothes in a bag, and take a shower.

If you have a radiation monitor, set it up somewhere safe. Put people through it if you suspect they were close to the center. If you miss some people- and you will- you can contact them later. Assume that if someone inhaled a lot, their skin will be very hot too, and so you don't need blood tests to estimate exposure. Take the people who have very high radiation readings and decontaminate them. Give them the most common and least harmful prophylactic treatments (Prussian Blue, DPTA) while someone's figuring out what was in the bomb. If anyone’s sick, burnt, or whatever, decontam them, take another radiation reading, and send them to the hospital before they stop breathing, in which case total exposure will be entirely moot.

Why did they test the polonium-exposed people in London? Two reasons. One, alpha emitters are very hard to detect at low amounts because they are easily stopped by skin, etc. Beta (electron) emitters like Sr and Cs are more amenable to whole-body counting [pdf]. Two, the treatment for Po exposure is Dimercaprol, a very nasty compound. You would probably want to know the exact exposure of someone before unnecessarily adminstering it.

Why would contaminated people even need a blood or urine test? According to the military analysis, 'to evaluate whether an exposure has occurred, and if so, its seriousness. ' In other words, to figure out what the exposure was. But for many heavy metals, including uranium, 'about 90% is excreted in urine by the kidneys within a few days.'

So how do you treat radiation exposure? You don't. There are exactly two treatment regimens for radiation exposure: chelators soon after to internally decontam, and palliative care to treat symptoms.* The FDA recommends guessing what isotope is most likely and beginning treatment right away, 'to significantly increase the probability of successful internal decontamination.' As for internal damage, it's done. A precise knowledge of how much damage there is will only tell patients what symptoms they might expect; it will never fix the problems. (Notice that the upshot of the London testing was 'Your lifetime risk of cancer is slightly higher. Cheers.')

For this we should spend millions of dollars on specialized labs? In North Carolina, no doubt.

*There is a third treatment, currently experimental, to boost bone marrow activity.