Path: utzoo!utgpu!watserv1!watmath!att!cbnews!military From: ames!ames!claris!portal!cup.portal.com!mmm@uunet.UU.NET Newsgroups: sci.military Subject: Nerve Gas Message-ID: <1990Aug18.182811.24916@cbnews.att.com> Date: 18 Aug 90 18:28:11 GMT Sender: military@cbnews.att.com (William B. Thacker) Organization: AT&T Bell Laboratories Lines: 49 Approved: military@att.att.com From: An earlier posting was mostly correct about how nerve gas works, but could use a little elaboration. Acetylcholine is used in some nerve-nerve synapses however its main feature w.r.t. nerve gas is that it is the signal used in neuromuscular junctions. The earlier poster was quite correct that the mechanism of death is asphyxiation. Acetylcholine is the "on" signal. Lacking a continuous assertion of the on signal, an enzyme called acetylcholinesterase cleaves this molecule into choline and acetic acid, which are re-absorbed by the nerve ending. Hardware types can think of acetylcholinesterase as "passive pull-down" of the on-signal. The experience of being hit with an acetylcholinesterase inhibitor is quite painful. Most skeletal muscles are paired, i.e. for each muscle there is an opposing muscle. When both muscles contract, you get muscle tearing and perhaps even bones breaking. (Well, if you inject this stuff into a frog, you get bones breaking -- but a frog has thin bones; I don't about humans; I've never injected a human :-) However, nerve agents are regarded (by those familiar with their effects) as very humane weapons. For a given degree of incapacitation, nerve agents cause far fewer deaths than conventional weapons. Among the wounded, a far greater number make a complete recovery. And, among people who survive a nerve gas attack, very few retain any memory of the experience. (This brings up an interesting ethical question -- does suffering really occur if the sufferer doesn't remember it?) Contrast this with conventional munitions. To be effective, they must expose the victim to an extreme concussion, or a severe wound. Either event is much more likely to cause death or permanent disability. Nuclear weapons are even worse -- a dose of prompt neutrons sufficient to incapacitate is lethal. A good book on the subject is TOMORROW'S WEAPONS. I forget the other details, like the author's name. It was published about 20 years ago. The author was the former head of DoD's chemical weapons program, so the book is heavily slanted toward that subject. BTW, common organophosphorus insecticides are just like nerve gas, except they have bulky side groups attached to reduce their toxicity toward higher animals. Insects perform a lot of their respiration through their skin (exoskeleton, actually), so these bulky molecules retain their pesticidal properties. Now if a person were to take some common insecticide like --------- and perform a -------------- reaction, to remove the side groups, you might get something interesting. Perfect for the amateur terrorist who buys all of his supplies at the local Safeway :-)