Search for Anthrax Additive Requires More Tests

W A S H I N G T O N, Nov. 1, 2001 -- A group of military scientists is feverishly examining the microscopic spores of anthrax sent to Sen. Tom Daschle for clues to a mystery that could have profound implications for the United States and its ongoing war on terror: Who made it?

Contained in the deadly sample that arrived in Daschle's office on Oct. 15 are additives used to make the normally inert bacteria a better killer, and exactly which additives they are could point investigators in the direction of the anthrax's source, and from there, perhaps, to who sent it.

Biological weapons experts say producing potent samples like the spores in the Daschle letter require advanced techniques that leave tell-tale markers to who made it — the known manufacturers of biological agents all have different ingredients and methods for creating their wares.

ABCNEWS reported last week that initial tests on the Daschle letter discovered the presence of one of those important additives, bentonite, an anti-clumping agent that makes the spores float through the air and into the lungs more easily, and which United Nations weapons inspectors have associated with Iraq.

This issue is critical. Making anthrax deadlier by mixing it with such additives is a trademark of sophisticated, well-funded, government programs, which could point to state-sponsorship of the mail attacks. Finding bentonite or silica, a similar additive, is one of the few solid leads investigators would have on the possible source of the contaminated letters that have been showing up in mailrooms from Florida to New York City.

But there is dispute over what the additives are. The White House and the head of the Army's biological laboratories in Ft. Detrick, Md., have denied bentonite was present, and said even if it was, it would not necessarily point to Iraq as the culprit.

They said investigators have not ruled out domestic or foreign sources, and, experts in the field note, the equipment used to treat anthrax with bentonite is available on the open market, which could lead investigators to a suspect in the United States.

But mineralogists suggest the matter of the bentonite may not be closed

Checking Ingredients

The government's top labs have run the Daschle anthrax sample through a series of tests. An electron microscope study found the Daschle spores looked "virtually identical" to those found in Iraq by U.N. weapons inspectors in 1994. But after subjecting it to a sophisticated X-ray test last week, the Army concluded it contained no bentonite, a clay comprised of several minerals, including aluminum.

For the Army, no aluminum equaled no bentonite.

"One of its principal ingredients is aluminum," said Maj. Gen. John Parker, overall commander of the military laboratories doing the analyses. "And I will say to you that we see no aluminum presence in the sample."

That assessment may prove correct, but not based solely on the absence of aluminum.

ABCNEWS has learned that at least two European chemical companies make a processed, aluminum-free bentonite. Mineralogist William Moll, who has mainly worked in private industry, says these synthetic bentonites are used as "free-flow agents" that give dry powders a "fluid" or "slippery" quality as the particles float through the air.

The existence of such bentonite means further tests are needed to rule out the presence of the troubling additive.

One of America's leading experts on mineral clays, Hayden Murray, a professor emeritus of geology at Indiana University, says a company based in Munich, Germany, removes aluminum from bentonite to create a finer, more refined additive than one could make from the bentonite deposits found in Iraq.

Murray says at least two American companies mine such high-quality bentonite, but the German company has a much larger customer base in the Middle East.

Last week, White House spokesman Ari Fleischer confirmed the Armed Forces Institute of Pathology found another additive — silica — in the Daschle anthrax. Like bentonite, silica is used in pharmaceutical powders all over the world and would make the anthrax float through the air more effectively.

When the United States was still in the biological weapons business back in the 1960s, U.S. scientists experimented with anthrax, silica and bentonite. The former Soviet Union also used silica in powders with anthrax.

Spray Dryers

In fact, federal officials say many countries have the materials, the technology, and the know-how to put pharmaceutical powders to deadly use. Yet as far as anyone knows, only the United States and the former Soviet Union have actually produced an anthrax weapon in powdered form.

But Iraq, for one, is believed to have been trying. In the 1980s, Baghdad purchased three spray dryers from a Danish company for research purposes. In 1988 and 1989, Iraqi officials asked the Danish company that manufactured the dryers to help identify companies that would sell silica, as well as two other drying agents, kaolin and maltodextrin.

Like many items employed in the production of germ weapons, the dryers and the chemicals were "dual use." Spray dryers, for instance, are commonly used to make powdered milk. U.N. weapons inspectors say the Iraqi dryers were eventually used to make biological weapons.

The FBI apparently has its own suspicions about the use of spray dryers in the germ attacks. When ABCNEWS phoned the company that sold Iraq the dryers, officials there said the FBI had called the previous day.

'Pure Spore' Clues

The concentration of spores in the Daschle sample is another potential clue scientists can use to find its source.

In creating a germ weapon, microbiologists must induce bacteria like anthrax into a spore state, a hardier form of the cells that protects them against extreme temperatures and other environmental stress.

Spores can be induced in various ways, but American scientists discovered one of the best techniques in the '70s, years after abandoning its offensive biological warfare program. Iraq improved on the U.S. method, creating a preparation that was almost 100 percent spores.

That fits Parker's description of what he saw when he looked at the Daschle sample. "I have looked at the specimen under the microscope, both the electron microscope and the scanning microscope, and I can say that the sample was pure spores," he said. Parker also said the spores were "uniform in size," and "highly concentrated."

In an amateur preparation, experts like former Soviet biological warfare scientist Ken Alibek would expect to see a mixture of anthrax organisms in different stages of development. "Like a mix of seeds and plants," says Alibek.

At times, the language of bacteriology sounds almost botanical. When an oval-shaped spore "germinates" it grows into a rod, which looks like a short pretzel stick. Microbiologists refer to this as the organism's "vegetative" state. Alibek would expect a "home-brewed" anthrax preparation to look like a hodgepodge of spores and vegetative cells.

'Ted Kaczynski With a Petri Dish'

But federal officials say even the level of purity in the Daschle sample is no proof that a foreign state is connected to the attacks. Instead, a theory favored by some federal investigators might be described as "Ted Kaczynski with a petri dish."

According to this view, "a disgruntled Ph.D." here in America could have launched this wave of bioterror with a "well-equipped laboratory" and a tiny speck of virulent anthrax, which is quite simple to nurture into large colonies. That is, if he get his hands on the right strain.

America's biowarfare scientists remain divided on this point. The trick is still making an effective powder, which requires more than an advanced degree in microbiology. Bill Patrick, former chief of "product development" at Fort Detrick in the waning days of the U.S. offensive biological weapons program, believes the small amount of anthrax recovered so far, apparently just 2 grams in the Daschle letter, points to "a small operation."

Patrick and another Fort Detrick veteran, Col. David Franz, both say they'd expect state-supported bioterrorists to use larger amounts of anthrax in more ambitious attacks. For Franz, the threshold of proof for state involvement is 50 kilograms, or 100 pounds of anthrax, an amount that could cause, under perfect conditions, Hiroshima-like casualties.

Former U.N. weapons inspector Richard Spertzel disputes this logic. He maintains that the use of a small amount of anthrax in these attacks does not prove the perpetrators only possessed a small amount. "Look at what they've accomplished with a few letters," says Spertzel. "They didn't need to use more."

Another dissenter from the prevailing conventional wisdom, Alan Zelicoff of Sandia National Laboratories, admits that a "disgruntled Ph.D." could get a hold of a virulent anthrax strain and culture it, but "he wouldn't know the aerosol physics to create the powder. This is a complex engineering problem," says Zelicoff.

Sources privy to the federal investigation say the tests on the Daschle sample are still under way. Even if these tests ultimately find bentonite, as well as silica, they will not prove Iraqi involvement. In the language of criminology, the manufacturing techniques, and the additives in the aerosol powders, may add up to a known modus operandi, but they are not "fingerprints."

Although Spertzel is convinced that the accumulating circumstantial evidence is "narrowing the field," he concedes that investigators may never know with certainty the identity of the terrorists behind the germ attacks.

"I don't think that we're going to see a smoking gun that's going to implicate this country, or that company," says Spertzel. "That's the hard thing to swallow with these anonymous attacks. You want to defend yourself, but from whom?"