SUBR CATEGORIES OF TERRORISTS INCIDENTS
There are five categories of terrorist
incidents: biological, nuclear, incendiary,
chemical, and explosive.
1. Biological agents pose serious threats
considering their fairly accessible nature and
the potential for their rapid spread. These
agents can be disseminated in the following
ways: aerosols, oral (contaminating food or
water), dermal (direct skin contact), or
injection. Inhalation or ingestion is the most
The Centers for Disease Control list
approximately 20 biological agents (bacterial
agents, viral agents and biological toxins)
which are considered as possibilities for
terrorist use. Following is a list of those
considered most likely to be used.
• Anthrax (Bacillus anthracis) infection is a
disease acquired following contact with infected
animals or contaminated animal products or
following the intentional release of anthrax
spores as a biological weapon. Exposure to an
aerosol of anthrax spores could cause symptoms
as soon as 2 days or as late as 6-8 weeks after
exposure. Further, the early presentation of
anthrax disease would resemble a fever or cough
and would therefore be exceedingly difficult to
diagnose without a high degree of suspicion.
Once symptoms begin, death follows 1-3 days
later for most people. If appropriate
antibiotics are not started before development
of symptoms, the mortality rate is estimated to
• Bacillus anthracis toxin (produced by
Clostridia botulinum) is the single most
poisonous substance known, and poses a major
bio-weapons threat because of its extreme
potency and lethality; its ease of production,
transport and misuse; and the potential need for
prolonged intensive care in affected persons.
Natural cases of botulism typically result from
food contamination (food not or incompletely
heated) with absorption of the toxin from the
gut or a wound. The incubation period for
food-borne botulism can be from 2 hours to 8
days after ingestion. Patients with botulism
typically present with difficulty speaking,
seeing and/or swallowing and may initially
present with gastrointestinal distress, nausea,
and vomiting preceding neurological symptoms.
• Plague (Yersinia pestis) is an infectious
disease of animals and humans found in rodents
and their fleas. Pneumonic plague occurs with
infection of the lungs. The incubation period is
1 to 6 days and the first signs of illness are
fever, headache, weakness, and cough productive
of bloody or watery sputum. The pneumonia
progresses over 2 to 4 days and may cause septic
shock and, without early treatment, death.
Person-to-person transmission of pneumonic
plague occurs through respiratory droplets,
which can only infect those who have
face-to-face contact with the ill patient. Early
treatment of pneumonic plague with antibiotics
• Smallpox (variola major) has an incubation
period of 7 to 17 days following exposure.
Initial symptoms include high fever, fatigue,
and head and back aches. A characteristic rash,
most prominent on the face, arms, and legs,
follows in 2-3 days. Smallpox is spread from one
person to another by infected saliva droplets
that expose a susceptible person having
face-to-face contact with the ill person.
• Tularemia (Francisella tularensis) is one of
the most infectious pathogenic bacteria known,
requiring inoculation or inhalation of as few as
10 organisms to cause disease. It is a zoonosis,
with natural reservoirs in small mammals such as
voles, mice, water rats, squirrels, rabbits and
hares. Naturally acquired human infection occurs
through a variety of mechanisms such as: bites
of infected arthropods; handling infectious
animal tissues or fluids; direct contact or
ingestion of contaminated water, food, or soil;
and inhalation of infective aerosols. Human to
human transmission has not been documented.
Aerosol dissemination by a terrorist would be
expected to result in the abrupt onset of acute,
non-specific febrile illness beginning 3 to 5
days later (incubation range, 1-14 days).
Treatment is with antibiotics.
2. Nuclear incidents are expected to take one of
two forms: threatened or actual detonation of a
nuclear bomb or threatened or actual detonation
of a conventional explosive incorporating
nuclear materials. It is unlikely that a
terrorist could acquire or build a functional
nuclear weapon. Dispersal of nuclear materials
with a conventional explosive would contaminate
the bombsite and raise environmental
decontamination and long-term health issues.
Nuclear indicators, short of actual detonation
or obvious involvement of radiological
materials, include observation for a Department
of Transportation placard or decal, and
radiation detection devices.
3. Incendiary incidents could be any mechanical,
electrical, or chemical device used to cause a
fire. Indicators of incendiary devices include
multiple fires, remains of incendiary device
components, odors of accelerants (e.g.,
gasoline), and unusually heavy burning or fire
4. Chemical agents fall into five classes: nerve
(disrupt nerve impulse transmission); blister
(severe burns to eyes; skin; respiratory tract;
blood (interfere with oxygen transport),
choking; and irritating (designed to
• Nerve agents are similar to organophosphate
pesticides, but with higher toxicity. Early
symptoms include uncontrolled salivation,
lacrimation (secretion of tears, especially in
excess), urination, and defecation. These agents
may resemble water or light oil and possess no
odor, and are best dispersed as an aerosol. Many
dead animals at the scene may indicate a nerve
• Blister agents are also referred to as mustard
agents due to their characteristic smell. They
can be absorbed through the skin, and clinical
symptoms may not appear for hours or days. These
agents are heavy, oily liquids, dispersed by
aerosol or vaporization.
• Blood agents interfere with oxygen transport
by the blood, resulting in asphyxiation.
Clinical symptoms include respiratory distress,
vomiting and diarrhea, and vertigo and
headaches. These agents are gasses, although
precursor chemicals are typically cyanide salts
and acids. All have the aroma of bitter almonds
or peach blossoms.
• Choking agents stress the respiratory tract by
causing edema (fluid in the lungs) which can
result in asphyxiation. Clinical symptoms
include severe eye irritation and respiratory
distress. Most people recognize the odor of
chlorine; phosgene has the odor of newly cut
hay. Both are gases and must be stored and
transported in cylinders.
• Irritating agents, also known as riot control
agents or tear gas are designed to incapacitate.
Generally, they are non-lethal; however, they
can result in asphyxiation. Clinical symptoms
include eye and throat irritation, respiratory
distress, and nausea and vomiting.
5. Explosive agents, i.e., bombs, can be 1)
readily made from commonly available materials
(e.g., ammonium nitrate fertilizer and diesel
fuel), 2) obtained from commercial sources
(e.g., blasting agents and explosives), or 3)
obtained from the military. These devices
account for 70 percent of terrorist attacks.