By the fall of 2002, the awe-inspiring anthrax of the previous spring had morphed into something decidedly less fearsome. According to sources on Capitol Hill, FBI scientists now reported that there was “no additive” in the Senate anthrax at all. Alibek said he examined electron micrographs of the anthrax spores sent to Senator Daschle and saw no silica. “But I couldn’t be absolutely sure,” Alibek says, “because I only saw three to five of these electron micrographs.” Even the astonishingly uniform particle size of 1.5 to 3 micrometers, mentioned in 2001 by Senator Bill Frist (R–TN), now included whopping 100-micrometer agglomerates, according to the new FBI description recounted by Capitol Hill aides. The reversal was so extreme that the former chief biological weapons inspector for the United Nations Special Commission, Richard Spertzel, found it hard to accept. “No silica, big particles, manual milling,” he says: “That’s what they’re saying now, and that radically contradicts everything we were told during the first year of this investigation.”
Military scientists did not back off their findings. The August/October 2002 newsletter from the Armed Forces Institute of Pathology (AFIP) reported that a mass spectrometry analysis found silica in the powder sent to Senator Daschle (The AFIP Letter, August/October 2002, p. 6). “This was a key component,” said the institute’s deputy director, Florabel Mullick, in the AFIP newsletter. “Silica prevents the anthrax from aggregating, making it easier to aerosolize,” she added. Frank Johnson, chief of AFIP’s Chemical Pathology Division, corroborated this in an interview. “There was silica there,” said Johnson, “there was no mistaking it.” Maj. Gen. John S. Parker, commander of the U.S. Army Medical Research and Materiel Command at the time of the attacks, says he saw AFIP’s lab reports. “There was a huge silicon spike” consistent with the presence of silica, he says. “It peaked near the top of the screen.”
Other agencies support this view today. For example, John Cicmanec, a scientist with the U.S. Environmental Protection Agency, says the Department of Homeland Security confirmed to EPA that the perpetrators did, in fact, use silica to weaponize the Senate anthrax spores. According to an abstract that Cicmanec will present at the annual meeting of the Society for Risk Analysis next month, this weaponized form of anthrax is more than 500 times more lethal than untreated spores.
The contradictory military data compelled the FBI to do some explaining. Sources on Capitol Hill say that in an FBI background briefing given in late 2002, Dwight Adams, one of the FBI’s topranking scientists, suggested that the silica discovered in the Senate anthrax was, in fact, silicon that occurred naturally in the organism’s subsurface spore coats. To support his thesis, Adams cited a 1980 paper published by the Journal of Bacteriology—a paper that Matthew Meselson, a molecular biologist at Harvard University, says he sent to the FBI. The authors reported that they found silicon, the element, in the spore coats of a bacterium called B. cereus, a close cousin of anthrax.
In the 23 years since the Journal of Bacteriology published these data, however, no other laboratory has published a report on significant amounts of silicon in the B. cereus spore coat, and many bacteriologists familiar with these data consider them an anomaly. Even the authors suggested the finding might have been due to “contamination.”
In December 2002, the FBI decided to test whether a high-grade anthrax powder resembling the one mailed to the Senate could be made on a small budget, and without silica. To do this job, the bureau called upon Army scientists at Dugway Proving Ground, a desolate Army test range in southwestern Utah. By February 2003, the scientists at Dugway had finished their work. According to military sources with firsthand knowledge of this effort, the resulting powder “flew like penguins.” The experiment had failed. (Penguins can’t fly.)
Military sources say that Dugway washed and centrifuged the material four times to create a pure spore preparation, then dried it by solvent extraction and azeotropic distillation —a process developed by the U.S. Chemical Corps at Fort Detrick in the late 1950s. It is not a simple method, but someone familiar with it might be able to jury-rig a lab to get the job done. As recently as 1996, Bill Patrick says he taught scientists at Dugway how to do this.
The FBI-Dugway effort produced a coarse powder. The spores—some dried under an infrared lamp and the others airdried —stuck together in little cakes, according to military sources, and then were sieved through “a fine steel mesh.” The resulting powder was placed into test tubes. When FBI officials arrived at Dugway to examine the results, a Dugway scientist shook one of the tubes. Unlike the electrostatically charged Senate anthrax spores that floated freely, the Dugway spores fell to the bottom of the test tube and stayed there. “That tells you the particles were too big,” says Spertzel. “It confirms what I’ve been saying all along: To make a good powder, you need an additive.”
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Today, there is no firm evidence to link Iraq—or any other government—to the anthrax attacks. But some weapons experts such as Spertzel are still inclined to look for a sponsor with deep pockets, and they say Hussein’s regime cannot be ruled out. Spertzel’s main point, however, is that only a state-run facility or a corporation has the resources to make an anthrax powder as good as the one mailed to the Senate.
