Did the subway sarin incident go to plan?

May 16, 2007 12:54 PM

SarinGasFilter: in the Aum Shinrikyo sarin gas attack on the Tokyo subway in 1995, 5 team members released a total of 5.5 litres of liquid sarin at 5 different locations. According to this Wikipedia article, "a single drop of sarin the size of the head of a pin can kill an adult," yet the total deaths = 12. Were Aum Shinrikyo aware that their sarin was spectacularly bad/ impure/ degraded, or were they aiming for significantly more fatalities?
posted by The_Partridge_Family to grab bag (9 comments total)

The problem with these kinds of weapons is that you really need to know how to develop the aerosol for them to properly disspate in the air and get into the lungs of your target. I remember reading how this cult just did not have the technical training to deliver the poison properly. In fact, gas weapons are difficult for government swith almost unlimited money and brainpower.

How many people you can kill per drop is a goofy metric. It assumes perfect penetration which is impossible in the field. Thats like saying a box of 100 bullets could kill 100 people, but in the military the death per bullet is extremely low.

Lastly, I'm not sure if they were shooting for a large amount of kills. This is terrorism and its effective with a handful of deaths.

That said, this article is informative

The Tokyo gas attackers settled on a simple delivery system. The gas is volatile. They packaged their product in a plastic bag, wrapped it in newspaper, put it at the exit to a subway carriage, and when the carriage came to a stop, stabbed the bag with the inevitable umbrella, and ran out to a waiting car or taxi. Three Underground lines were almost simultaneously attacked in this way; Murakami distinguishes seven different sites on these lines. It's believed that a total of ten men made the primary deliveries.

Sarin is deadly, but its real-life potency is often overstated (as in the first translator's footnote to this book): it is pure sarin that is so lethal and it is not very easy to make it pure. The Tokyo gas attack relied on a fairly impure product. Sarin is almost odourless, but this stuff seems to have smelled like paint thinner. The number of people killed was quite small, a total of 12. Many, many more passengers suffered from complex after-effects. An early official summary stated that 3796 people were affected. The more commonly cited number today is about five thousand. A recent study found that around 30 per cent of these people are still affected, many of them by post-traumatic stress disorder.

posted by damn dirty ape at 1:06 PM on May 16, 2007

a single drop of sarin the size of the head of a pin can kill an adult

Probably under ideal circumstances, which the subway attack definitely was not. The deployment method was very primitive (compared to something like a airburst attack), and the victims had access to first-world medical care.

The external link to the Register article at the bottom of the page illustrates some of the difficulties in procuring and deploying nerve gas.
posted by meowzilla at 1:09 PM on May 16, 2007

This doesn't answer your question but here is an extensive article on the rise and fall of the Aum Shinrikyo cult including their previous attacks. The attack is described on this page.
posted by euphorb at 1:19 PM on May 16, 2007

As referenced in the above article, check out Haruki Murakami's Underground, which details that many of the sarin packages were not fully pierced with the umbrella tips as the perpetrators exited the trains.
posted by avocet at 1:33 PM on May 16, 2007

the victims had access to first-world medical care.

Interesting to note: Murakami's book Underground actually talks about how bad medical attention was at first. It was as though no one would believe the victim's claims of feeling sick. There were other problems with first responders, too, as I recall.
posted by malaprohibita at 1:39 PM on May 16, 2007

And a gallon of water can drown a hundred people. But getting them to inhale it is the hard part.

Their serin was apparently just fine. They chose an ineffective delivery method. I couldn't find the relevant stats in my quick skim, but I believe there were more fatalities from the train cars where the plastic bag was more liberally punctured.

At any rate a very very small percentage of it became airborne, which is where it needs to be to kill.
posted by Ookseer at 2:11 PM on May 16, 2007

As an aside, what I find interesting about the whole sarin gas attack is not how many people actually died, but how many people thought they were exposed. The hospitals were overwhelmed with hundreds of people who thought they might have been exposed but were actually perfectly healthy. If they were aiming for large scale fatalities, they failed. However, if they were aiming to terrorize and cause mass panic, they suceeded.
posted by GlowWyrm at 3:10 PM on May 16, 2007

Judging from their other attempted attacks, they were definitely after mass casualties. In one of them they rigged a spray nozzle to the roof of a station wagon & drove around Tokyo spraying (thankfully inert) Anthrax into the air. In some ways they were amazingly effective but others shockingly inept. They bought HIND helicopters from Russian generals, had them disassembled & shipped to Japan then found out they didn't know how to put them back together.
posted by scalefree at 5:47 PM on May 16, 2007

I believe (I think from Underground) that the sarin was dissolved in acetonitrile. I also vaguely remember that it wasn't all that concentrated.

As people above have said, a major reason the casualties were so low is that the sarin was not effectively dispersed in the air. Part of the problem may have been that the attackers were afraid of killing themselves - it would be hard to effectively disperse sarin in a subway car without getting enough on you to kill you.
posted by pombe at 8:57 PM on May 16, 2007