Anthrax Scares: The Bomb Threat Of The 90s

Terrorism has been a hot topic throughout the emergency response community for the past several years. Acts of terrorism occurring within the United States are a very real possibility. Bombings have been the weapons of choice in the past; however, biological weapons present a credible threat for the future.

Anthrax, in particular, is a likely choice of the terrorist for a number of reasons. It is highly lethal with a mortality rate of 80% to 90% from inhalation exposure. Deadly concentrations are much less than for chemical nerve agents. Anthrax is relatively easy to produce and occurs naturally in many parts of the world, including the United States. It is also easy to deliver in its most deadly form, aerosol.

Photo by Robert Burke
Responders to a reported anthrax incident will need Level B protection at a minimum for packaging the suspected agent and decontaminating victims.

Anthrax weapons can be produced at a fraction of the cost of other weapons of mass destruction, with equal effectiveness. One kilogram (2.2 pounds) of anthrax can be produced for less than $50 and if properly aerosolized, under appropriate weather conditions, could kill hundreds of thousands of people in a metropolitan area.

Within the past 10 months, terrorism in the United States has taken on a new twist, the "anthrax hoax." Threats boasting the release of anthrax or the exposure of individuals have occurred in at least 17 states and continues to spread. The FBI reports it investigates new anthrax hoaxes on a daily basis. Targets have included abortion and family-planning clinics, federal and state buildings, churches, courthouses, public schools, dance clubs and office buildings. Threat mechanisms have included mailed letters with a white powder inside boasting "you've just been exposed to anthrax," threatening letters, notes written on walls in buildings, telephoned threats and materials left in buildings. These incidents are much like bomb threats. The potential for an anthrax incident is very real, but all of the events that have occurred so far have been hoaxes.

Each time an anthrax threat occurs, though, it must be taken seriously. Response to these types of incidents causes much the same response from fire, police and EMS as would a real anthrax release. Response resources are tied up for hours, building activities are disrupted, as is traffic around the buildings and neighborhoods. Thousands of dollars are lost from business disruptions and the cost of emergency responses.

Media coverage plays into the attention the responsible persons are trying to obtain and encourages copycats to create similar hoaxes in other locations. With the type of response the emergency community is giving to these hoax events, a terrorist wouldn't need to have anthrax or for that matter any other biological material to create an act of terrorism - the threat alone serves the purpose.

Photo by Robert Burke
Separate decontamination lines must be set up for non-ambulatory victims of an anthrax release.

On Oct. 30, 1998, abortion clinics in Indiana, Kentucky and Tennessee received letters claiming to contain anthrax. The letters carried postmarks from Cincinnati. In Indiana 31 people, including a mail carrier, were thought to have been exposed and so they were decontaminated with chlorine bleach. They were then transported to hospitals, decontaminated again and given antibiotics. Hospital workers who treated the "victims" were also given antibiotics.

In Los Angeles 91 people were quarantined for more than eight hours after a report that anthrax had been released into the air-handling system of a federal building. Once again, antibiotics were administered to those thought to be exposed. A state office building in Wichita, KS, was evacuated after an envelope was found in a stairwell with a white powder and note claiming it was anthrax. Between 20 and 25 people were believed to have been contaminated. Fifteen were decontaminated as a precaution.

On Dec. 14, 1998, a school district secretary opened a letter which read "You've been exposed to anthrax." Several days later, a U.S. Bankruptcy Court in Woodland Hills, CA, was targeted and more than 90 people were treated with antibiotics. Three days later, telephoned threats caused two Van Nuys, CA, courthouses to be evacuated, resulting in 1,500 people being quarantined for several hours. It has been estimated the incidents in California alone have cost the taxpayers $500,000 per occurrence. The list of incidents and locations goes on and on, but the circumstances and outcomes are similar and they have all been hoaxes.

What Is Anthrax?

Anthrax (bacillus anthracis), also known as woolsorter's disease, is a bacterial illness common among farm animals, but it can also affect humans. Two thousand to 5,000 cases of naturally occurring anthrax are reported every year throughout the world. It most commonly occurs in South and Central America, southern and eastern Europe, Asia, Africa, the Caribbean and the Middle East. About five cases are reported in the United States each year and occur mostly in Louisiana, Mississippi, Oklahoma, South Dakota and Texas.

Considered to be an "occupational disease," the people most likely to contract anthrax naturally work around animals. These people include veterinarians, ranch and farm workers, and those who work with animal carcasses, hair and wool. Anthrax spores are very persistent and remain viable for years in soil, dried or processed hides, skins and wool. They can survive in pond water for two years, in milk for 10 years, dried on filter paper for 41 years and dried on silk threads for 71 years. (An island off the Scottish Coast that was used by the British for anthrax tests during World War II is so contaminated it still cannot be inhabited).

Anthrax spores are resistant to many disinfectants, drying, heat and sunlight. Anthrax as a disease has three forms, cutaneous, pulmonary or inhalation, and intestinal. It is in the spore form that anthrax is the most dangerous. While most of the powders suspected of being anthrax during hoax events have been white in color, resembling talcum powder, anthrax spores resemble cinnamon or cocoa in color and consistency. Spores, however, could be mixed with another substance and present a different color. Therefore, identification cannot be based on the physical appearance of a suspected substance. There isn't any particular smell associated with anthrax spores, so identification by odor will not be possible. Field identification tests are available to detect the presence of anthrax, but laboratory tests must be conducted to confirm the true identify of a suspected material.

Cutaneous anthrax is the most common naturally occurring form of the disease and is the most curable, if treated. Without treatment, the disease can be fatal in 5% to 20% of cases. Cutaneous anthrax is contracted by contact with a source of infection through openings in the skin, such as a cut or abrasion, or other opening. Exposure usually occurs on an exposed area of the face, neck or arms.

The odds of being infected by anthrax in this manner are approximately 1 in 100,000. The incubation period can range from one to six days. Within approximately three days of exposure, an elevated, reddened papule develops at the point of contact, which may be slightly itchy. Swelling may involve the entire limb where the pimple forms. Treatment centers on the administration of antibiotics; penicillin is preferred, but erythromycin, tetracycline, ciprofloxacin or chloramphenicol can also be used.

Intestinal anthrax occurs when undercooked meat from infected animals is eaten, but this type of exposure rarely occurs in the United States. Symptoms from ingestion of infected meat begin with an acute inflammation of the gastrointestinal tract. This is accompanied by nausea, loss of appetite, vomiting and fever. These symptoms are followed by abdominal pain, vomiting of blood and severe diarrhea. About 25% to 60% of those exposed in this manner will die. Inhalation anthrax (woolsorter's disease) is by far the most deadly and the most likely form a terrorist would use. This route of exposure involves the inhalation of dry anthrax spores. It is reported by the U.S. Army that the lethal dose of anthrax through inhalation would be approximately 8,000 to 10,000 spores.

Photo by Robert Burke
Decontamination setups used for hazardous materials also work well with anthrax and other weapons of mass destruction (WMD) agents.

Spores lodge in the alveoli of the lungs, which provide a medium for the spores to germinate and grow. In order for the spores to enter the alveoli, they must be from one to five microns in size. Symptoms of inhalation anthrax resemble a common cold initially and progress to severe breathing problems and shock after several days. Fever, malaise and fatigue are early symptoms which may be accompanied by non-productive cough and chest discomfort. These symptoms may be followed by a short period of improvement ranging from hours to two to three days. The improvement is then followed by abrupt development of severe respiratory distress accompanied by dyspnea (difficulty breathing), diaphoresis (profuse sweating), stridor (harsh vibrating sound heard during respiration when the airway is obstructed) and cyanosis (bluish or purplish skin discoloration as a result of oxygen deficiency in the blood). Shock and death will occur one to two days after the onset of symptoms.

Inhalation anthrax is nearly always fatal once symptoms have begun to show. Antibiotics have minimal effect on inhalation anthrax. Those who do recover from all types of the disease may develop an immunity. Second attacks from the disease are unlikely.

A vaccine is available for anthrax and members of the U.S. armed forces are currently being vaccinated. The vaccine is not, however, expected to be available for emergency response personnel any time soon, nor is wide spread vaccination considered to be warranted. Administration of the vaccine occurs in six doses - three initial doses given at two-week intervals followed by boosters at six, 12 and 18 months. After the initial six doses, an annual booster is required.

Response Guidelines

As a result of the recent number of anthrax scares, the FBI's Weapons of Mass Destruction (WMD) Unit has developed guidelines for emergency responders. These guidelines are designed to reduce the impact of a hoax event on the response system, potential victims and the community:

  • "Persons exposed to anthrax are not contagious and quarantine is thus not appropriate."
  • "All first responders should follow local protocols for hazardous materials incidents involving biological hazards. Upon receipt of a threat, a thorough hazard risk assessment should be conducted. Upon notification, the FBI will coordinate a risk assessment in conjunction with the health department and other authorities on biological agents to ensure timely dissemination of appropriate technical advice."
  • "Any contaminated evidence gathered at the scene should be triple-bagged. Individuals should be advised to await laboratory test results, which will be available within 48 hours. These individuals do NOT need to be placed on chemoprophylaxis (antibiotics) while awaiting laboratory test results to determine whether an infectious agent was present."
  • "The individual needs to be instructed that if they become ill before laboratory results are available, they should immediately contact their local health department and proceed immediately to a pre-determined emergency department, where they should inform the attending staff of their potential exposure."
  • "Responders can be protected from anthrax spores by donning splash protection, gloves, and a full-face respirator with High Efficiency Particulate Air Filters (HEPA) (Level C) or self-contained breathing apparatus (SCBA) (Level B). Victims who may be in the immediate area and are potentially contaminated should be decontaminated with soap and water: no bleach solutions are required. A 1:10 dilution of household bleach (i.e., Clorox at 5.25% hypochlorite) should be used only if there is confirmation of the agent and an inability to remove the materials through soap and water decontamination. Additionally, the use of bleach decontamination is recommended only after soap and water decontamination, and should be rinsed off after 10 to 15 minutes. Technical assistance can be immediately provided by contacting the National Response Center (NRC) at 800-424-8802."
  • "If the envelope or package remains sealed (not opened), then first responders should not take any action other than notifying the FBI and packaging the evidence. Quarantine, evacuation, decontamination and chemoprophylaxis efforts are NOT indicated if the envelope or package remains sealed. Also, anthrax will likely be visible as a powder or powder residue. The absence of visible powder is a strong indicator that anthrax is not present."
  • "The use or threatened use of a weapon of mass destruction (including anthrax) is a violation of federal law. See Title 18. United States Code, Section 175 and Section 2332a. It should be reported to the FBI immediately."
  • "This information is provided by the WMD Operations Unit of the Federal Bureau of Investigation and the National Domestic Preparedness Office (NDPO), in coordination with the Centers for Disease Control, the Department of Health and Human Services/Office of Emergency Preparedness, and the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID). The NDPO was established to coordinate the federal government's efforts to prepare the nation's response community for threats involving weapons of mass destruction. Contact your local FBI office if confronted by a WMD threat."

Initial Actions

When responding to a suspected terrorist threat or incident involving anthrax or any other weapon of mass destruction, the emergency responder's first concern needs to be containment. Remember the responsibilities of the first responder to any type of hazardous material:

  • Recognition/identification
  • Isolation
  • Notification
  • Protection.

Limit the exposed area and the people allowed into the area. If the air-handling system is involved, have the system shut down. The entire building does not have to be evacuated unless it is suspected that the agent has been aerosolized and has entered the air handling unit, spreading it throughout the building.

In the case of a letter or package without aerosolization, contain the incident to the room involved. Evacuation of the building will not be necessary. Anthrax spores in a package or envelope do not present any particular hazard as long as no one touches, inhales or ingests the material. Have the person who opened the package or envelope close it with the material inside. Have people potentially exposed keep their hands away from their faces, and do not touch eyes, nose or mouth. Hands should be washed with soap and water while waiting for decontamination facilities to be set up.

Appropriate actions taken by first responders can reduce the impact these types of incidents will have on the facility, response personnel, and the community. Downplaying the incidents will help to reduce the number of copycat occurrences and the development of complacency among responders and the public.

Robert Burke, a Firehouse® contributing editor, is the fire marshal for the University of Maryland and has served on state and county hazmat response teams. Burke is a veteran of over 16 years in career and volunteer fire departments, serving as assistant chief and deputy state fire marshal. He holds an associate's degree in fire protection technology and a bachelor's degree in fire science, and is pursuing a master's degree in public administration. Burke is an adjunct instructor at the National Fire Academy and Maryland Fire and Rescue Institute, and is the author of the textbooks Hazardous Materials Chemistry For Emergency Responders, published in 1997, and Counter-Terrorism for Emergency Responders, to be published this year. He can be reached on the Internet at