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Chem/Bio Warfare

Chemical Warfare, Part One: Introduction

I don’t often deal with politics and world events on this site (much less than I thought I might when I started it.) There are usually plenty of other worthy writers out there who are saying just what I would, so I’ve settled on science (and the business of science) as my ecological niche in the Blogosphere. But these days, current events may be crossing paths again with chemistry, so I thought I’d use my scientific background to cover a topic that I fervently hope will end up being of no interest at all: chemical warfare.

There’s a reasonable chance that an invasion of Iraq would trigger use of Saddam Hussein’s remaining chemical weapons stores (either against US troops, or on a missile lobbed into Israel, as in the Gulf War.) The Iraqis themselves have credited their chemical warfare capacity with giving them an edge against the much larger Iranian forces in the 1980s, and Hussein has (infamously) used what appears to have been the nerve agent VX against his own Kurdish population.

On the home front, there are terrorist possibilities as well, both with industrial chemicals as well as with more specific war gases. I’ll take on the subject in several postings over the next few days (with my more traditional blog material showing up in between, as time permits.)

To begin with, it’s important to realize that chemical munitions, nasty as they are, do not have the same destructive potential as atomic or nuclear explosives. As readers will see, releasing a van full of (say) benzyl bromide would be a tremendous irritant. A vanload of mustard gas would be far worse than that. A similar quantity of nerve gas would, of course, be an atrocity.

But keep in mind that a fission (or worse, a fusion) weapon could be contained in the same van, and would be many orders of magnitude more terrible in every way. Fortunately, they’re also many orders of magnitude harder to acquire. Much depends on keeping that difficulty as high as possible.

Chemical weapons are, then, more likely to actually be encountered, and they’re plenty bad enough. The ideal chemical agent would be totally incapacitating or lethal, hard to detect, extremely potent, and easy to deliver and disperse. Since the advent of modern chemical warfare in the First World War, those qualities have largely led to the use of toxic gases or their corresponding liquids. The delivery problems of solid agents have kept them from being as fully developed.

Different compounds meet these criteria to different extents. A much wider variety of agents were tried out during the First World War than is generally realized, almost 40 different compounds. (See this excerpt from a 1926 US government report for a comprehensive list and a lot more detail than I have space to go into.) That list was a real surprise, personally, since I realized that I have a number of these things in my lab. I have to say, I’d never thought about loading them up and throwing them at someone – which is probably the same thought many chemists had during the war. Several of the things on the list are still relevant to today’s situation.

Others aren’t. Many substances from that era are little more than irritating tear gases. I’ve been exposed to some of them myself in my chemical career, most memorably a face full of benzyl bromide fumes in graduate school. It wasn’t truly incapacitating – I still had plenty of capacity to lurch around the lab toward the eye wash fountain, cursing and banging into things. Such compounds would be of little use against anyone properly equipped, and would do little lasting harm even to unprepared civilians.

Some of the other World War I irritants were had a delayed onset, designed to make later gas-mask wearing very uncomfortable. By which time, the plan was, more lethal agents would be in the area, exposing troops who otherwise would have been better protected. This sort of thing is still a potential military problem, but there’s still no point in enemy use of such compounds against civilians who won’t have masks to start with.

No, for both battlefield use and in terrorism, the lethal agents are the ones to worry about. I’ll be covering these in some detail over the next few posts – how they’re obtained, how likely they are to be encountered, and how they’re dealt with.