1) OVER THE PAST SIX MONTHS, have federal authorities altered their working theory of last fall’s anthrax murders? No, not much. On November 9 last year, even before the anthrax outbreak’s fifth and final fatality had been recorded, the FBI called a press conference to unveil its “linguistic and behavioral assessment” of “the person” purportedly responsible. It was “highly probable, bordering on certainty,” the Bureau announced, that a single “adult male” had prepared and mailed all the contaminated letters at issue. This man “probably has a scientific background,” “may work in a laboratory,” and is familiar with the area around Trenton, New Jersey–where the envelopes were postmarked. He suffers a pronounced psycho-social deformity: “He lacks the personal skills necessary to confront others” and “if he is involved in a personal relationship, it will likely be of a self-serving nature.” Moreover, crucially, the suspect appears to be an American. “We’re certainly looking in that direction right now, as far as someone being domestic,” said James R. Fitzgerald, head of the FBI’s Behavioral Analysis Unit. By the end of November, after an unopened anthrax letter addressed to Sen. Patrick Leahy was found in sequestered congressional mail, investigators were telling reporters on background that they might well be dealing with someone who has a particular animus against Democrats. His politics aside, the man’s citizenship, at least, achieved a measure of official status by mid-December, when homeland security chief Tom Ridge, seconded by White House spokesman Ari Fleischer, acknowledged that where once “some of us” had been “thinking more in terms of foreign sources,” now “a lot of the information and a lot of the things they’ve been able to detect from the investigation and follow-up leads . . . they’re looking more inward to a domestic source.” On January 29, confirming its impression of the domestic source’s professional profile, the FBI sent a letter to all 40,000 members of the American Society for Microbiology which informed those scientists that it is “likely one or more of you know this individual.” On February 26, the New York Times reported that what had once been a “pretty tight list” of investigative subjects in the world of microbiology–perhaps 100 U.S. laboratories and their employees–had been whittled down to a group of 35 to 50 “researchers or technicians” and then narrowed still further to maybe 18 or 20 people with the means and potential motive to send deadly bacteria through the mail. Two weeks ago, numerous published reports suggested that the FBI has recently lost a fair bit of confidence in the focus of its investigation; the universe of potential suspects, “law enforcement sources” now say, actually numbers in the “thousands.” Nevertheless, the government continues to expect that the one guilty man among those thousands will turn out to be an American biological researcher of some kind. 2) What makes them think he’s an American? The FBI has declined to explain its profiling rationale in any detail, and Tom Ridge’s references to “follow-up leads” and other “things they’ve been able to detect” remain ambiguous. But a woman named Barbara Hatch Rosenberg, whom the Bureau has consulted, and whose analysis of the case mirrors its own in certain key respects, has tirelessly publicized the results of some ambitious amateur detective work. Rosenberg is a research professor of environmental science at the State University of New York in Purchase. She also directs a working group on biological weapons verification for the Federation of American Scientists. And in a running “commentary” she has maintained on the federation’s Internet site (www.fas.org/bwc/news/anthraxreport.htm), Rosenberg argues that “multiple, blatant clues” left “seemingly on purpose” all make clear that “the perpetrator of the anthrax attacks is American.” First off, the letters in which his spores were wrapped warned recipients to take an antibiotic, establishing that he “did not aim to kill”–as would be the goal of a genuine al Qaeda operative–but sought simply “to create public fear.” Furthermore, according to Rosenberg, the spores themselves were prepared following the “optimal U.S. process” secretly perfected decades ago by Army biowarfare specialists at Ft. Detrick in Frederick, Maryland. “The anthrax in the letters,” Rosenberg flatly asserts, “was either made and weaponized in recent years in a U.S. government or contractor lab for biodefense purposes, or by the perpetrator on his own.” Either way, last fall’s bacteriological terrorism against the United States was undoubtedly “an inside job.” Given the understandably intense jealousy with which federal investigators have guarded whatever hard evidence they themselves have accumulated in the case, media attempts to substantiate the FBI’s conviction that a deranged current or former government scientist is behind the anthrax attacks have necessarily been based almost exclusively on the speculation of outside “experts.” And no such expert has been more widely or respectfully cited, at the highest reaches of American journalism, than Barbara Hatch Rosenberg. After all, notes the New Yorker, Rosenberg is “not chopped liver.” She is a “veteran molecular biologist” with a long-term professional interest in biological weapons–and “deeply concerned hazel eyes.” Which may be true. But it is also true that this veteran molecular biologist’s sensational pronouncements betray a surprisingly uncertain grasp of contemporary genetic research and clinical protocols concerning Bacillus anthracis. And a surprisingly limited familiarity with anthrax-related military and civil-defense projects around the world. And a surprisingly unscientific, even Oliver Stone-scale, incaution about the “facts” at her disposal. Rosenberg claims the FBI has known the anthrax mailer’s precise identity for months already, but has deliberately avoided arresting him–indeed, may never arrest him–because he “knows too much” that the United States “isn’t very anxious to publicize.” Specifically, according to an account the hazel-eyed professor offered on BBC Two’s flagship “Newsnight” telecast March 14, the suspect is a former federal bioweapons scientist now doing contract work for the CIA. Last fall, you see, the man’s Langley masters supposedly decided they’d like to field-test what would happen if billions of lethal anthrax spores were sent through the regular mail, and “it was left to him to decide exactly how to carry it out.” The loosely supervised madman then used his assignment to launch an attack on the media and Senate “for his own motives.” And, this truth being obviously too hot to handle, the FBI is now trying very hard not to discover it. What if “some kind of deal is made that the perpetrator just disappears from view,” Rosenberg worries aloud? She appears already to have taken proactive steps to thwart such a conspiracy. Over the past several months, using language lifted almost verbatim from Rosenberg’s website, ABC News and the Washington Times have both fingered the same unnamed “top scientist” as the FBI’s only (never-to-be-revealed) anthrax suspect. Except that the poor man turns out to be a former Ohio laboratory technician who has never done bacteriological research of any kind–and whose unfortunate history of alcoholism has lately reduced him to working in a Milwaukee-area bowling alley. Which bowling alley has no known ties to the CIA’s Directorate of Operations. Barbara Hatch Rosenberg’s theory is crackpot. 3) Well, wait a minute. Wasn’t the anthrax powder mailed last fall chemically identical to stuff produced in classified U.S. labs? That’s far from clear, and even if it were clear it probably wouldn’t help solve these crimes. In order to produce inhalation anthrax, bacterial spore-particles must be small enough–no more than a couple or three microns wide–to reach a victim’s lower respiratory mucosa. And for decades, until very recently, scientists believed that the mechanical milling required to produce such fine dust artificially would also produce a charge of static electricity sufficient to bind anthrax spores together into oversized, harmless clumps. To prevent this from happening–to keep the spores separate, “floaty,” and therefore deadly–bioweapons specialists in the United States and elsewhere went to considerable lengths to identify a chemical additive that would, like throwing a sheet of Bounce into your clothes dryer, remove the static. It has been widely reported, but never confirmed, that American scientists eventually settled on silica. It has been just as widely reported, and more or less confirmed, that the Soviet and Iraqi biowarfare programs each at some point used a substance called bentonite, instead. The Armed Forces Institute of Pathology has performed energy dispersive X-ray spectroscopy on anthrax powder recovered from at least two of last fall’s letters and has apparently discovered trace amounts of silica, but no sign of aluminum, an element basic to the best-known and most common form of bentonite (montmorillonite). Based on this result, government investigators have concluded, according to the Washington Post, that “it is unlikely that the spores were originally produced in the former Soviet Union or Iraq.” On the same basis, and getting similarly ahead of herself, Barbara Hatch Rosenberg has decided the spores were prepared by a rogue or sanctioned U.S. laboratory worker. But the fundamental chemistry involved here cannot sustain such certainty. Silica, or silicon dioxide, is simple quartz or sand, the most abundant solid material on earth. “Bentonite” is the generic term for a class of natural or processed clays derived from volcanic ash, all of which are themselves mineral compounds of silica–and not all of which necessarily contain aluminum. In other words: Trace amounts of silica in an anthrax powder are consistent with the presence of bentonite. And the absence of aluminum from that powder is not enough to exculpate any foreign germ-warfare factory thought to have used bentonite in the past. The FBI and Rosenberg seem also to have ignored what has been standard practice in U.S. biodefense, medical, and veterinary laboratories for most of the past thirty years: Work with virulent strains of anthracis in dried-spore, aerosolized form is virtually unheard of. Pentagon production of weapons-ready–and presumably silicate–anthrax powder was abandoned during the first Nixon administration. The U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID) at Fort Detrick, for example, doesn’t even own the requisite technology to manufacture dry aerosols; USAMRIID scientists, like their civilian counterparts, use only “wet” anthrax–which has usually been genetically altered or irradiated to render it non-toxic. There is one known exception to this rule. Four months ago the Army’s Dugway Proving Ground in Nevada confirmed that in recent years it has conducted occasional, limited experiments with fully pathogenic anthrax powders–reportedly to test prophylactic measures against a frightening, vaccine-resistant strain of the bacterium thought to have been cooked up by Russian geneticists during the early 1990s. Here’s the thing, though: The Army is mum on the question, but there is no reason to think that Dugway’s virulent aerosols (every speck of them fully accounted for, laboratory officials insist) were prepared with silica, according to the rumored 1960s recipe. The science of environmental engineering, which hardly existed in the 1960s, has lately revealed a great deal of new information about the dispersal patterns of anthracis and other airborne microbes. As a consequence, old assumptions about the effect of electricity on the aerosolization of bacterial pathogens–like those from a just-opened letter–have been revised: Lethal quantities of lethally small anthracis particles can and do spread over a large area, on normal indoor air currents and in very little time, whether or not they have been treated with an anti-static compound. So whoever was responsible for last fall’s bioterrorism wouldn’t have needed to add silica to his anthrax powder at all. But he–or she, or they–might have had use for it while manufacturing that powder to begin with. Before they were kicked out of Iraq for good, U.N. weapons inspectors concluded that Saddam’s military biologists were no longer relying on mechanical milling machines to render dried-out paste-colonies of anthracis bacteria into fine dust, but had instead refined a spray drying technique that produced the dust in a single step. And the suspected key ingredient in this Iraqi innovation, interestingly enough: pharmaceutical-grade silica, a common industrial drying agent. 4) But last fall’s anthrax was milled mechanically, so it can’t have come from Iraq, right? We don’t know that it was milled, really. Published reports conflict on this point, and those news accounts that do suggest the anthrax was milled invariably attribute the intelligence to federal investigators impressed by the super-granulated quality of the Leahy sample. In fact, evidently concerned that the Leahy letter might thus tend to confirm the Barbara Hatch Rosenberg conspiracy theory at its most rococo (i.e., that someone walked the anthrax straight out of a CIA lab), certain “government sources” have lately begun putting out word that the stuff was actually too good to be American. Two weeks ago, an item in Newsweek described a “secret new analysis” said to be circulating through high-level Washington, according to which analysis the Leahy letter’s powder was “ground to a microscopic fineness not achieved by U.S. biological weapons experts.” Researchers have found evidence of “intense milling,” Newsweek explained: individual, free-floating anthracis spores, something our own government’s scientists have “never seen” before. But that’s absurd. Individual, free-floating anthracis spores are what those scientists look at every day. And it’s hardly a secret. During a December 15 Centers for Disease Control-sponsored conference on post-exposure prevention of inhalation anthrax–you can find the transcript on CDC’s website–Dr. Louise Pitt of USAMRIID discussed in considerable detail how her colleagues at Ft. Detrick do their anthracis research. The spores, she said, “are diluted to the desired concentration in sterile distilled water, water for injection. Our aerosols are extremely well characterized and defined. The particle size of the aerosol has a mass-meeting-aerosol diameter between .8 and 1.4 microns. That means that the aerosols that we are generating are basically single-spore aerosols. There’s very, very little clumping of two spores. They are single-spore aerosols.” And remember, Ft. Detrick does not employ a mechanical milling process. Because, as it happens, people like Dr. Pitt have discovered much easier ways to make what our experts persist in calling the Leahy letter’s “weapons-grade” anthrax: If they want it in a mist, they dilute the spores in water, as USAMRIID does. And if they want their anthrax dry, in a powder, they run it through what is essentially a very fancy flour sifter, a device commercially available throughout the world. This practice, too, has been specified in the open literature. A “Risk Assessment of Anthrax Threat Letters” published last year by Canada’s Defence Research Establishment Suffield (DRES), for instance, was based on a bacterial specimen prepared in the “routine manner.” Agar-grown cultures were dried into a “clumpy, undistinguished mess.” And the mess was then filtered with a sifter, separating the largest chunks and leaving behind a final powder containing “a high proportion of singular spores.” Under a microscope, of course, singular spores, both milled and unmilled, look exactly the same. 5) What about the fact that last fall’s attacks involved the American “Ames” strain of anthrax? Careful. On October 25, at the height of the crisis, Tom Ridge announced that the bacteria were of “the Ames strain” or “an Ames strain.” That same day, however, Dr. Jeffrey Kaplan, director of the CDC, said that anthracis samples taken from letters mailed to Sen. Tom Daschle and the New York Post–and from the spinal fluid of Florida photo editor Bob Stevens, the outbreak’s first victim–were consistent with “a number of different strains.” Kaplan’s deputy, Dr. Julie Gerberding, added a further nuance. The Daschle, Post, and Stevens samples–“strains,” she also called them–were “indistinguishable.” But if they were indistinguishable, how could they be different “strains”? During a November 14 CDC “telebriefing,” Gerberding acknowledged that “it’s very important to set the record straight on this issue.” And she made a valiant attempt to do so: “These strains in the various regions of the country that we’re dealing with are indistinguishable on the basis of their antibiotic susceptibility as well as their typing using more sophisticated molecular tools, and they have some characteristics in common with several of the naturally acquired strains of anthrax that have been seen in animals in the United States and in the United Kingdom and elsewhere. . . . But they’re not identical.” Got that?
