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Anthrax: Scientists Criticize FBI’s Theory on Lone Culprit in Attacks Some experts have said the spores used in last fall’s anthrax attacks required technical knowledge and production capabilities beyond that of a lone individual, contrary to the FBI’s views, the Washington Post reported today (see GSN, Oct. 23). Instead of pursuing a “lone individual” theory, investigators might want to examine if state-sponsored terrorism played some role in the attacks, or if the person responsible obtained the spores from a foreign biological defense program, experts said. “In my opinion, there are maybe four or five people in the whole country who might be able to make this stuff, and I’m one of them,” said Richard Spertzel, chief biological inspector for the U.N. Special Commission from 1994 to 1998. “And even with a good lab and staff to help run it, it might take me a year to come up with a product as good.” An FBI profile released last November described the person believed to be responsible as a “lone individual” with “some” scientific knowledge who could have made the spores in a primitive laboratory for as little as $2,500 (see GSN, Aug. 15). The FBI also said there appeared to be no “direct or clear link” between the attacks and foreign terrorism. That profile, however, clashed with what was known about the complexity of the spores used in the attacks, according to experts. The profile was issued three weeks after U.S. Army scientists examined spores taken from a tainted letter sent to U.S. Senate Majority Leader Tom Daschle (D-S.D.). The scientists found that the spores were processed to a size of 1 trillion per gram — 50 times finer than the spores made through the now-closed U.S. biological weapons program and 10 times finer than known Soviet-made anthrax, the Post reported (see GSN, June 13). “Just collecting this stuff is a trick,” said Steven Lancos, executive vice president of Niro Inc., a leading manufacturer of spray dryers, viewed by several sources as the likeliest tool needed to weaponize anthrax. “Even on a small scale, you still need containment. If you’re going to do it right, it could cost millions of dollars.” Silica The FBI had initially ruled out the possibility that Iraq might have been behind the anthrax attacks because the spores used were coated in silica to aid in their dispersion, rather than mineral bentonite, believed to have been used in Iraq’s anthrax weaponization program. That belief, however, appears to be based on a single sample taken by U.N. authorities in the mid-1990s, according to the Post. As early as 1989, the U.S. Defense Intelligence Agency reported that Iraq was acquiring silica to use in chemical weapons and in 1998, Iraq informed the United Nations that it had conducted an artillery test of a live biological agent that used silica as a dispersant, the Post reported (see GSN, April 24). “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, he said. The silica-coated spores used in the attacks were probably produced through mixing fine glass particles, known as “fumed silica,” with the spores in a spray dryer. “I know of no other technique that might give you that finished product,” Spertzel said. Fumed silica particles are tiny and will stick to larger particles, such as an anthrax spore. Fumed silica particles also absorb moisture and can acquire an electric charge, both of which keep the particles from clumping together and aid in their dispersion, according to the Post. “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.” While some fumed silicas are difficult to produce, two brands — Aerosil and Cab-O-Sil — are internationally available for purchase in bulk, according to the Post. The Soviet Union used Aerosil in producing biological agents, said Ken Alibek, former deputy director of the Soviet biological weapons program. A 1991 Pentagon memo said Iraq had “imported approximately 100 MT (metric tons) of Aerosil during the last 8-9 years.” The United Nations also reported in the 1990s that Iraq possessed about 10 metric tons of Cab-O-Sil, Spertzel said. Equipment The anthrax production would also require expensive and specialized equipment — several hundred thousand dollars worth, according to experts. Niro’s least expensive spray dryer costs about $50,000. An electron microscope, needed to examine the results of the production process, also costs hundreds of thousands of dollars, the Post reported. The United Nations discovered three Niro spray dryers in Iraq during inspections conducted in the 1990s, according to the Post. Two of the spray dryers were destroyed and the third was sterilized before it could be inspected, Spertzel said. Whoever produced the anthrax spores used in the attack would “need some experience” with aerosols and “would have to have a lot of anthrax, so you could practice,” Edwards said. “You’d have to do a lot of trial and error to get the particles you wanted.” All together, “you would need (a) chemist who is familiar with colloidal [fumed] silica, and a material science person to put it all together, and then some mechanical engineers to make this work . . . probably some containment people, if you don't want to kill anybody,” Lancos said. “You need half a dozen, I think, really smart people”(Gugliotta/Matsumoto, Washington Post, Oct. 28). For further information, see: CDC Frequently Asked Questions About Anthrax Journal of the American Medical Association Background on Anthrax GSN Anthrax Attack Chronology (Dec. 12, 2001)
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