The anthrax attacks in Florida, New York and Washington have raised concerns of a broader biological attack against the United States. The delivery method of the anthrax spores — via the postal system — offers some insight into the capabilities and motives of the perpetrators. At the same time, it reveals technical and perhaps even political limitations constraining broader, more indiscriminate attacks.
An employee of CBS News in New York tested positive for cutaneous anthrax infection, the company announced Oct. 18. Anthrax infections linked to two other major networks — NBC and ABC — and at the Florida offices of American Media Inc. have already surfaced; workers at the Hart Senate Office building in Washington, D.C., and at the New York City office of Governor George Pataki also have been exposed.
The attacks, which have caused one death thus far, have all been linked to mail containing anthrax spores. This delivery method offers some insight into the capabilities and motives of the attackers. At the same time, it reveals technical and perhaps even political limitations constraining a broader, more indiscriminate biological attack.
Fear of biowarfare has deepened in the United States and around the world since Sept. 11. The appearance in Florida of a case of inhalation anthrax, the first in the United States in more than two decades, quickly changed these fears into a reality.
As with the attacks on the World Trade Center and the Pentagon, the anthrax strikes have been conducted using simple, unconventional methods — converting America's communications infrastructure into a delivery method for bio-agents. But the idea of sending anthrax spores through the mail is not new. From late October through late December 1998, several letters apparently containing anthrax were sent to clinics and businesses in four states. Although all proved to be hoaxes, anthrax has long been studied as a prime organism for biowarfare.
Anthrax is an attractive agent of death for several reasons. First, the bacterium — Bacillus anthracis — is relatively easy to procure. It has long been available to the research community and is also endemic throughout most of the world, affecting livestock and other grazing animals. Second, it is easy to culture and isolate. Finally, it can be highly lethal in certain forms.
Despite its potential deadliness, there is a vaccine available, particularly to high-risk groups such as researchers and veterinarians. This means scientists and potential terrorists working with anthrax could do so with relatively little risk of infection. Further, anthrax can survive in spore form for long periods with few special storage requirements.
Anthrax can be contracted in three ways: by touch, through ingestion or through inhalation. In the first case, the bacteria or spores enter the skin through cuts or abrasions. This is the most common form of anthrax and the easiest to treat. Without treatment, mortality rates are near 20 percent, but with common antibiotics, the chances of death are extremely small, according to the Journal of the American Medical Association. Gastrointestinal anthrax, contracted by eating undercooked meat from an infected animal, is rare. The deadliest form of the infection, inhalation anthrax, has a mortality rate of nearly 100 percent.
The fact that the attackers used mail as a vector reveals some of the limitations of anthrax as a weapon, however. Despite the ease with which anthrax bacteria can be obtained and grown, "weaponizing" the spores is much harder. Anthrax spores must be isolated, dried and milled into a fine powder — with particles measuring between one and five microns in diameter — for maximum effectiveness.
The final stage of making anthrax into an aerosol form requires special equipment and facilities to ensure uniformly sized particles with high concentrations of active spores. Some reports, however, suggest that a crude but effective facility for drying anthrax as a powder could be constructed from the same machinery used to make powdered milk. Keeping this final product from clumping together into particles larger than five microns requires additional processing.
The complexity of these final steps has kept many nations from producing weapons-quality anthrax for aerial distribution. Even Iraq, which conducted substantial biological research, prepared anthrax as a liquid, seriously reducing the potential efficacy of any attack. The Japanese cult Aum Shinrikyo tried several times to release anthrax and other biological agents in Tokyo between 1990 and 1995, all unsuccessfully.
The relatively refined sample sent to the office of Senate Majority Leader Tom Daschle did not necessarily meet the milling specifications for weapons-grade anthrax, according to Army researchers.
Delivering anthrax by mail suggests that the group or groups responsible have not yet produced sufficient quantities of anthrax or acquired the appropriate delivery method for a larger strike. Instead, by targeting the media and government officials, they have gained maximum effect with minimum effort. A few mailed letters have resulted in several thousand false alarms and hoaxes — tying up police, fire, medical and hazmat teams, stirring panic among the populace, interfering with mail delivery and worrying politicians and the military.
There may be another reason for sending anthrax through the mail rather than releasing large quantities of spores over a major city. If the attacks were the work of a group related to Osama bin Laden's al Qaeda, hitting discrete targets may be the result of political constraints. Bin Laden, the target of a weeks-long bombing campaign on Afghanistan, sees his main chance for salvation in undermining the U.S. coalition. To do so, however, he must engender the sympathies of Arab and Muslim nations.
The attack on the World Trade Center, which killed more than 5,000 people, was seen by much of the Islamic community as being over the top, resulting in too many civilian casualties to be justified even by Washington's international policy or Israel's killings of Palestinians. In fact, Tahirul Qadri of Pakistan, a prominent Muslim cleric, publicly denounced bin Laden and his Taliban protectors, saying the destruction of the World Trade Center was "no jihad" and that those responsible for the Sept. 11 attacks "put the lives of millions of Muslims across the world at risk," UPI reported Oct. 17.
Large-scale anthrax attacks on the United States would only serve to further weaken bin Laden's position among Muslim nations. Even Libyan leader Moammar Gadhafi has condemned anthrax attacks, calling anthrax a "weapon of mass destruction," according to Reuters.
Political leaders and their mouthpieces in the media, however, could be considered more legitimate military targets. This would allow a continuation of the terror war in America without driving Islamic nations closer to the United States. Given these political restraints and the technical difficulties of deploying anthrax, a widespread anthrax attack on a major metropolitan area remains unlikely. For the average American, the chances of getting anthrax remain extremely low.
For the government and the media, targeted use of biological and chemical agents remains a threat. Considering the increased attention and security being paid to mail and anthrax at this time, however, the next terrorist strike in the United States will likely come from another quarter, keeping Washington off-balance and disrupting the ability of the United States to get back to normal soon.