Bush administration officials have acknowledged that the anthrax attacks were an important motivator in the U.S. decision to confront Iraq, and several senior administration officials say today that they still strongly suspect a foreign source -- perhaps Iraq -- even though no one has publicly said so.That Iraq had the wherewithal to make the anthrax letters does not mean it is the guilty party. Still, the FBI's early dismissal of the possibility may have prematurely closed a legitimate line of inquiry.
"Iraq almost certainly had their anthrax spores in a powdered form," Spertzel said. "They had used silica gel to aid in dispersibility of [wheat] smut spores, and also indicated they were looking at it as a carrier for aflatoxin," a carcinogen.
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Several sources agreed that the most likely way to build the coated spores would be to use the fine glass particles, known generically as "fumed silica" or "solid smoke," and mix them with the spores in a spray dryer. "I know of no other technique that might give you that finished product," Spertzel said.
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"This concept of using something that would serve as a dessicant and a carrier at the same time is new," said Harvard University chemical engineer David Edwards. "It's a diabolically brilliant idea."
Fumed silica has myriad uses, mostly as a thickening agent in products including ceramics, house paint, toothpaste and cosmetics. It is not widely known as an aerosol additive.
"If you're going to put it into the lung, there has to be a mechanism to clear it, otherwise you just fill up somebody's lung with silica after repeated dosings," said Dalby, of the Aerosol Lab. The anthrax mailer, he noted, obviously wasn't worried about giving his victims silicosis.
Some fumed silicas are extremely difficult to make, but at least two -- Aerosil and Cab-O-Sil -- are readily available and sold commercially in bulk. Either product, in theory, could be used to coat anthrax spores. Aerosil is based in Germany and Cab-O-Sil, in Boston. Both firms have offices around the world.
Ken Alibek, a former deputy director of the Soviet bioweapons program now running an Alexandria biotechnology firm, said the Soviets used Aerosil in agent powders, and a classified Defense Department memo in 1991 said Iraq had "imported approximately 100 MT [metric tons] of Aerosil during the last 8-9 years." Spertzel said the United Nations reported in the 1990s that Iraq had 10 metric tons of Cab-O-Sil, probably destined for its chemical weapons program.
Beggin' your pardon, but this is absolutely critical information. The article deserves all the prominence it can get.
Yipes... this is the 'magic additive' that threw so many people off? Jeez, I use this stuff as an additive in museum exhibit resins... people are surprised it could be used in the anthrax powdering process?