Thursday, December 04, 2003

Still tracking anthrax

Responding to last night's post about the anthrax case, Tristero writes in to observe:
Towards the middle/end of the article, the author notes a lot of disputes over the notion that the anthrax was particularly "well-made." Frankly, the new theory could be merely political change of focus rather than new scientific evidence.

There is simply no way to tell what theory's more likely without reading the Science report carefully and I suspect, even then, the chemistry issues are so complex that only an expert in the field would be able to assess the evidence:

Matsumoto writes that U.S. intelligence officials briefing experts from other NATO countries told them that the anthrax powder contained polymerized glass, which "leaves a thin glassy coating that helps bind the silica to particle surfaces."

But as the Science article notes, other scientists advising the FBI have concluded that the anthrax powder contained no additives. In a briefing on Capitol Hill late last year, Matsumoto writes, FBI scientist Dwight Adams suggested that the element silicon was naturally present in the spores and that no silica was added.

A similar dispute continues over experiments at the Army's Dugway Proving Ground to try to reproduce the powder in the letters using various kinds of equipment. The goal was to "reverse-engineer" the mailed anthrax to try to figure out how it was made.

Government sources familiar with the work told The Sun in April that the Dugway researchers felt they had succeeded in reproducing the powder and concluded that it was made with relatively inexpensive equipment and limited expertise.

Others familiar with the work, including former United Nations bioweapons inspector Richard O. Spertzel, said the powder made at Dugway did not float as freely as the powder mailed to the senators.

Whether changing scientific conclusions have reduced the FBI's focus on Hatfill is uncertain. Any change of strategy might have resulted from the arrival of a new assistant FBI director in charge of the Washington field office, which is running the anthrax investigation.

My friend Paul deArmond also writes in to observe, along the same lines:
Read carefully, the muddle on particle size and additives still exists:

* The particle size distribution of the Senate letters is still murky. I frankly don't believe the Frist report of "1.5 to 3.0 uM" because it's too narrow and too small (essentially no clumps bigger than four spores.) The Alibek report of 1-100 uM is fuzzy because Alibek says he only saw a very small number of electron photomicrographs (could have been cherry-picked to mislead).

* The issue of additives is still up in the air. There are conflicting sources, but the weight of evidence is on the side of there being some additive.

Long story short, the quality of the anthrax is more likely due to the knowledge and experience of who made it. There is no evidence of any super-duper exotic equipment needed.

The Science article is problematic because it states conflicting evidence but doesn't resolve the issues. The particle size problem is black, or white, no wait it's black. Same deal with the additives. There was a letter to the NYT and WP from Alibek and Meselson saying they had seen electron photomicrographs of the Senate sample that showed no "fumed silica." This wasn't mentioned in the article (maybe because Alibek and Meselson have credibility problems -- Meselson was wrong about the Sverdlosk incident and later got it right) but it deserved mention. So the Science
article has some problems of emphasis.

There has long been very substantial evidence that the early and late mailings were physically very different. I'm now leaning towards two batches because of the dog that didn't bark in the night -- no controversy over additives in early mailings.

Now here's the zinger. Assuming there were two different processes used to prepare the final product, were they both from the same fermentation run? Scott Shane suggested to me in a phone conversation that the second batch was re-centrifuged and reduced to dry powder from what was left over from the first mailings. There is no certainty that this happened like this, but Scott seemed to suggest that it was likely. Why, I don't know and he wouldn't say. If so, the attacker had access to a lab (centrifuge, dryer, bio-containment and all that stuff) DURING October 2001.

This lab would not have to be very big. I figure that 4' x 4' x 8' would be sufficient to contain all the equipment based on the descriptions of various processes. Scott has repeatedly referred to the existance of a "tabletop" weaponization process.

One of things that is unfortunate about the Science article is that it gave away far too much technical details. Not enough that anyone would be able to reconstruct the process on the public information, but enough that it might give a little help to somebody who was already a long ways down the road.

I'll keep posting on the case as news emerges, or as my superb letter-writers keep sending me material.

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