July 03, 2007

This was a fairly irresponsible article

The latest CP 'dirty bomb' scare story isn't just bad because the original study it's based on is not linked to by either the newspaper or the DRDC's own website, allowing people to make up their own minds from the source.

It's not just irresponsible because the report seems basically a rehash of the Federation of American Scientists' previous effort in this genre.

The real problem is that in covering a report that will undoubtedly have said that the disruption and injury will be the real cause of damage, it does nothing to alleviate that same panic. Journalism as a public service, my ass.

Case in point: A dirty bomb would result in "mass anxiety [despite no direct fatalities], a rush on Toronto's medical facilities [by people who don't need help] and an economic toll [for cleanup and lost work] of up to $23.5 billion.... The nightmarish scenario..." Um, hey, look, a costly cleanup and a bunch of hysterics hassling emergency staff is a bad thing, sure, but "nightmarish?"

Case in point: "Mere placement not explosion of a backpack containing 1,000 curies of radioactive cobalt-60 in packed B.C. Place Stadium during a four-hour sporting event would claim about 85 lives and result in economic costs of up to $8 billion."

Leave aside that a human exposed to that quantity of unshielded cobalt-60 has a 100% chance of dying immediately after 20 mins exposure, and that the shielding for a typical cobalt source of this size sufficient to carry it around weighs about 500 lb., making this really a suicide attack of a different variety. The actual calculation here is that 60,000 people fit in BC Place. Of these people, approximately 12,000 will die of cancer at some point in their lives. If the attack were carried out as described, that lifetime risk, assuming everyone was equally irradiated, would mean 12,085 eventually would: in all likelihood statistically undiscernible. Yes, it would be very bad to be sitting in the same row with the slowly dying backpack-guy, just as it would be if he had a backpack full of high explosive instead. That could have been pointed out.

The scary radioactive-green circles in the Google Earth screenshots that accompany the article are probably less scary than you'd think, too. They're gradated in "0.1, 0.01, 0.03 and 0.015," which, assuming it's similar to the previous FAS report, is probably the percentage increases in cancer deaths, lifetime. So if you're in the outer, 0.015 band, and you live there your entire life, your death from cancer risk will increase from roughly 20 percent to... 20.015 per cent. Or, put another way, if 20,000 people lived in that band, rather than 4,000 of them dying from cancer, 4,003 would... assuming their permanent residence in the circle area. (That's just an assumption: there is no actual legend on any picture of the graph I've seen yet. It could also be rems per year, which would change the numbers above, slightly. If 0.015, etc. are the measure of something else, I'll be happy to recalculate the above. The point is, in an article where the quoted experts are all saying the real risk to life is pretty overblown, the art provided is dangerously alarmist itself, and having no explanatory legend doesn't help.)

Another fact that might have been mentioned is that the sources in the study are really quite large: at 10g (1,000 Ci) of cesium-137 or 20g (1,000 Ci) of cobalt-60, you're really talking blood or food irradiation sources. For the record, the U.S. Nuclear Regulatory Commission handles about 300 missing radioactive material reports a year. However, between 1996 and 2001, those 1,000-plus reports totalled up to 11.2 Ci from all sources missing in the States. Which is also why I'm somewhat skeptical that the 2003 Red Deer theft the CP story refers to being actually of a "gauge" that contained anywhere near the 20 curies of stolen Am-241 that the DRDC study's least dangerous scenario postulates. Most of the americium/cesium sources found in industrial gauges are in the 50 millicurie range: you'd need about 400 of them to equal 20 Ci. (By comparison, your average smoke detector has about 1 microcurie of Americium, or one 50,000-th of the source in a standard moisture/density gauge, or one twenty-millionth of the curies in the DRDC's lesser-danger scenario.) A 20 Ci source would be found in something like a well-logging tool, a class of equipment which is fairly tightly monitored in North America (for sure, if stricter measures are required to secure these sorts of big sources found in mining, hospitals, and food irradiation facilities from theft, go for it, by all means, but that's not an unsolvable problem).

The threat with "dirty bombs" was always not the fatalities, but the panic combined with the long-term denial of a major cultural landmark per bomb. Per dollar or per gram, there are deadlier things for terrorists to use. Fair enough, radiation detectors, calibrated to a fairly high gain to avoid false positives, are not a bad thing to have at major tourist locations, sporting events, etc. But articles like this would really be much more responsible if they encouraged people NOT to drive out of town immediately, or flood the hospitals, and you can't say this one does that.

UPDATE: The CP team expands on their earlier article. If the Red Deer theft they refer to again was, in fact, a well-logging tool, not a "gauge" as the writers incorrectly refer to it, that could well make it the most significant theft of radioactive material in all of North America in the last decade; it's hard to think of anything else even close. How nice of the RCMP to get around to mentioning it to us four years later. Of the remaining "76 radioactive devices" mentioned in the article, it would be really interesting to know how many were gamma emitters in the 20-curie-plus range (the lower limit of usefulness for a serious dirty bomb). My guess is that at most there was just that one.

As far as leaving a "silent bomb" (unshielded gamma source) in "a park", the Chechens tried that in Russia in 1995... although in fact they never removed it from its shielding, thereby undoubtedly saving the bombers' lives. The problem is that no one will ever know it's there unless you tell them in a press release (or keel over while planting it, I suppose), as the effect of the radiation on death rates would be so minuscule and long-term. For much less effort, you can just plant nothing, send the release and still get a comparable amount of panic. There is a marginal threat of "silent bombs" against major landmarks and other enclosed high-density locales such as airports and airplanes, but our parks are pretty safe that way.

Posted by BruceR at 03:04 PM

Depends on what your definition of 'same' is

From old colleague Doug Saunders, writing for the Globe and Mail:

"Investigators say the car bombs, using cylinders of compressed propane or oxygen and large quantities of gasoline and shrapnel-producing nails, are the same as Iraqi bombs such as one that killed 87 people in Baghdad two weeks ago."

In a similar high-quality analogy, the recent English car 'bombs' were also the same as the donut I had for breakfast this morning, in that neither contained any actual explosive.

"But the apparently bumbling nature of the attacks has given little comfort to security officials. Instead, it has roused a deeper fear:"

That my neurosurgeon may, too be a bumbling moron literally too stupid to set himself on fire? No, sadly not.

Posted by BruceR at 11:26 AM