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Last Updated

03 Nov 2002

Source:  Baltimore Sun, November 3, 2002.

Anthrax powder from attacks could have been made simply

Single maker a possibility, scientists now theorize

By Scott Shane, Sun Staff

The anthrax powder in the poisoned letters that killed five people last year could have been prepared using tabletop equipment costing a few thousand dollars, according to two scientists with knowledge of the FBI's yearlong investigation.

While experts consulted by the FBI believed early in the investigation that the anthrax might contain silica or other sophisticated additives to make it float more easily in the air, the consensus now is that no additives are present and that the anthrax was probably made using a relatively simple process, the scientists say.

"There's really nothing all that special about it," said one of the scientists, who spoke on the condition that they not be identified. "There are many ways to do it."

The conclusion that manufacturing the powder would not require spray-dryers costing tens of thousands of dollars or other elaborate machinery points away from the possibility that the anthrax was made by a state bioweapons program such as Iraq's. It suggests that the powder could have been prepared by a single person with the right knowledge in a relatively simple clandestine lab.

The FBI appears to have focused on that theory for months, questioning dozens of scientists with ties to the U.S. biodefense program. But with no arrest in sight, some conservative critics have suggested that the bureau should reconsider the possibility that the powder might have been made in Iraq or by a foreign scientist working for al-Qaida.

Such criticism grew louder late last summer after a former Army bioterrorism expert, Dr. Steven J. Hatfill, accused the FBI and media of destroying his career and reputation by targeting him in the investigation. He has adamantly denied any connection to the attacks.

The powder in the letters addressed to Senate Majority Leader Tom Daschle and Sen. Patrick J. Leahy was made of virtually pure anthrax spores, the tough, dormant form of the Bacillus anthracis bacteria, scientists say. The powder contained about 1 trillion spores per gram, close to the theoretical limit of purity.

But one of the scientists who described the powder to The Sun said that such purity can be achieved using relatively simple methods, such as repeatedly spinning the anthrax mixture in a centrifuge and washing out non-spore materials.

While anthrax produced by Army weapons makers in the old U.S. offensive biological warfare program had a lower purity, that was because of techniques they used for efficient, large-scale production, the scientist said. The bioweapons makers of the 1950s and '60s could have made trillion-spore-per-gram anthrax easily on a smaller, laboratory scale, the scientist said.

In order to get a better idea of what equipment and methods were used by the mail attacker, the FBI has asked scientists to try to "replicate" the mailed anthrax using different production techniques, FBI Director Robert S. Mueller told reporters Friday.

The work will be performed at the Army's Dugway Proving Ground in Utah, where scientists have made tiny quantities of dangerous anthrax powder for many years to test detection equipment and decontamination procedures for U.S. troops.

One official said scientists conducting the current anthrax-making experiments at Dugway for the FBI are working with the Ames strain of anthrax used in the mail attacks. At least half a dozen different powders are to be made, the official said.

Matthew S. Meselson, a Harvard University biologist who has examined electron microscope photographs of the mailed anthrax for the FBI, said the powder appeared to be pure spores, but did contain some clumps, probably because of exposure to humidity. State biowarfare programs have used additives to reduce clumping and make the spores more deadly.

Meselson said the confusion over the possibility of a silica additive may have risen because X-ray studies of the powder detected the element silicon, one component of silica. But he said silicon is naturally present in anthrax, noting a 1980 Journal of Bacteriology paper that found an "unexpectedly high concentration of silicon" in anthrax spores.

Mueller said Friday that the FBI still believes in its profile of the anthrax attacker as a loner with some scientific training and access to Ames anthrax, a strain identified by the Army's biodefense lab at Fort Detrick in 1981 but distributed since then to at least two dozen other labs.

But he denied that the FBI has been limited by any single theory. "We have never ruled out any scenario, and to the extent that there are leads that come up, whether it be to individuals or methods of manufacturing or what have you, we pursue them," Mueller said.

"Am I satisfied? No, because we don't have the person or persons responsible identified and charges being brought against them," Mueller said.

"Are we making progress? Yes. And we continue to make progress," he said.

Because notes in some of the letters revealed that the powder was anthrax and urged the recipient to take penicillin - a warning that reduced the likely death toll - some analysts have suggested foreign terrorists are not the most likely perpetrators.

Instead, the analysts say, the attacker might be an American trying to alert the nation to the threat of bioterrorism.