Some of America's top biological warfare scientists are edging closer to a conclusion they've resisted since receiving word of the first anthrax infection in Florida — that the recent germ attacks involved an expertise only a government could provide.
Richard Spertzel, who directed the U.N. Special Commission biological weapons inspectors in Iraq, says a second confirmed case of pulmonary anthrax in Florida has deepened his suspicion that the attacks had the support of a foreign government. According to this view, agents of a state-run biowarfare program, or rogue scientists from a nation with a biological arsenal, may have provided the perpetrators with advice, and possibly with the agent itself.
One indicator, Spertzel says, is particle size. Inducing pulmonary, or inhaled, anthrax requires 8,000 to 10,000 spores embedded in particles between one to five microns in diameter. That amount would fit on the period at the end of this sentence.
If the particles are smaller than one micron, they are exhaled. Larger than five microns, and chances are the particles will lodge in the nose, or be caught in cilia that line the trachea. These are very narrow parameters.
Although spores of these precise dimensions do occur in nature, the chances of digging them up from soil, their natural habitat, are slim. The chances of inhaling them while walking in the woods are not only slim; they're unheard of.
So a would-be anthrax terrorist wouldn't prospect for these spores; he'd grow them. The next step is making an aerosol. That's the hard part.
A Select Club
Bill Patrick, a scientist who used to make anthrax weapons for the United States, patented a secret process that involved freeze-drying the spores, milling the resulting anthrax "cake" to yield particles of the proper diameter, then coating them with a special mixture to dampen electrostatic charges that cause clumping. Patrick calls this making the particles "slippery."
It's these particles that "deliver" the spores. A good anthrax "munition" requires more know-how than he says he'd expect to find in a laboratory run by al Qaeda, Osama bin Laden's network, which U.S. officials believe was behind the Sept. 11 hijacking attacks.
The Russians have this know-how. So do the Iraqis, among others. But it's a rather select club.
This is one reason why former UNSCOM chief Richard Butler has echoed Spertzel's apprehension about reports from the Czech government that hijacker Mohamed Atta met with an Iraqi agent in Prague months before the Sept. 11 attacks.
Did the Iraqi provide Atta, the Egyptian pilot considered a linchpin in the World Trade Center attacks, with anthrax? "It's not yet concluded," says Butler, who says the United States is trying to answer this question with the help of the Egyptian government.
Investigators also have yet to point a finger at any one person or entity in the anthrax probe.
"While organized terrorism has not been ruled out," FBI Director Robert Mueller said today, "so far we have found no direct link to organized terrorism."
Looking at the Specs
In the effort to identify where the agents found in Florida, New York and Washington came from, forensic scientists stand to learn more from the particles' "manufacturing specs" than they would from the spores' DNA signature.
For decades, microbiologists have exchanged anthrax strains for research with few restrictions, even the most virulent isolates. Unless its a rare strain, Spertzel says the spores used in the attacks could have come from anywhere.
The "Ames" strain has been the focus of much speculation in the press, as law enforcement sources say it was the source of the Florida exposures. But it isn't that rare. The strain was extracted from a dead cow in Ames, Iowa, in the 1950s, then sent to the U.S. Army Medical Research Institute of Infectious Diseases around 1980 for research.
British and American scientists discovered that Ames was one of the strains that defeated the licensed U.S. and British anthrax vaccines. Quite simply, it killed vaccinated guinea pigs. (Before you get too scared, antibiotics successfully kill the Ames strain). One can find Ames "reference strains" in laboratories around the world.
But if the agents used in the attack are found to contain the telltale presence of certain compounds used in a professional drying process, this could be a very revealing clue. For instance, the presence of aluminum clay, an anti-clumping agent employed in an air-drying process for anthrax, would point to professionals rather than amateurs, and narrow the field of possible suppliers.
It's clear the Florida cases involved a less elegant preparation with spores of an inconsistent size. Still, someone succeeded in manufacturing tens of thousands of particles, or more, to the required size to infect two victims with pulmonary anthrax. That took more than a mortar and pestle.