agents are organisms or toxins that can
kill or incapacitate people, livestock,
and crops. The three basic groups of biological
agents that would likely be
used as weapons are bacteria, viruses,
and toxins. Most biological agents are
difficult to grow and maintain. Many break
down quickly when exposed to sunlight and
other environmental factors, while others,
such as anthrax spores, are very long lived.
Biological agents can be dispersed by spraying
them into the air, by infecting animals
that carry the disease to humans, and by
contaminating food and water. Delivery
Aerosols — biological
agents are dispersed into the air,
forming a fine mist that may drift
for miles. Inhaling the agent may cause
disease in people or animals.
Animals — some
diseases are spread by insects and
animals, such as fleas, mice, flies,
mosquitoes, and livestock.
Food and water
contamination — some
pathogenic organisms and toxins
may persist in food and water supplies.
Most microbes can be killed, and
toxins deactivated, by cooking food
and boiling water. Most microbes
are killed by boiling water for one
minute, but some require longer.
Follow official instructions.
Person-to-person — spread
of a few infectious agents is also
possible. Humans have been the source
of infection for smallpox, plague,
and the Lassa viruses.
Specific information on biological agents
is available at the Centers for Disease
Control and Prevention’s Web site,
Before a Biological
are guidelines for what you should do
to prepare for a biological threat:
- Check with your doctor to ensure
all required or suggested immunizations
are up to date. Children and older
adults are particularly vulnerable to
- Consider installing a High Efficiency
Particulate Air (HEPA) filter in
your furnace return duct. These filters remove particles
in the 0.3 to 10 micron range and
will filter out most biological agents that
may enter your house. If you do
not have a central heating or cooling system, a
stand-alone portable HEPA filter
can be used.
Filtration in Buildings
Building owners and managers should determine the type and level of filtration
in their structures and the level of protection it provides against biological
agents. The National Institute of Occupational Safety and Health (NIOSH)
provides technical guidance on this topic in their publication:
Guidance for Filtration and Air-Cleaning
Systems to Protect Building Environments
from Airborne Chemical, Biological, or
Radiological Attacks. To obtain
a copy, call 1(800)35NIOSH or visit Guidance for Filtration and Air-Cleaning Systems to Protect Building Environments from Airborne Chemical, Biological, or Radiological Attacks (DHHS (NIOSH) Pub No. 2003-136) to
download NIOSH Publication 2003-136.
During a Biological Attack
In the event of a biological attack, public
health officials may not immediately
able to provide information on what you
should do. It will take time to determine
what the illness is, how it should be treated,
and who is in danger. Watch
television, listen to radio, or check the
Internet for official news and information
including signs and symptoms of the disease,
areas in danger, if medications or
vaccinations are being distributed, and
where you should seek medical attention
you become ill.
The first evidence of an attack may be
when you notice symptoms of the disease
caused by exposure to an agent. Be suspicious
of any symptoms you notice, but do not
assume that any illness is a result of
the attack. Use common sense and practice
If you become aware of an unusual and
suspicious substance nearby:
- Move away quickly.
- Wash with soap and water.
- Contact authorities.
- Listen to the media for official instructions.
- Seek medical attention if you become
If you are exposed to a biological agent:
- Remove and bag your clothes
and personal items. Follow official instructions
for disposal of contaminated items.
- Wash yourself with soap and water
and put on clean clothes.
- Seek medical assistance. You may be
advised to stay away from others or
After a Biological Attack
In some situations,
such as the case of the anthrax letters
sent in 2001, people may be alerted to
potential exposure. If this is the case,
pay close attention to all official
warnings and instructions on how to proceed.
The delivery of medical services for
a biological event may be handled differently
to respond to increased demand.
The basic public health procedures and
medical protocols for handling exposure
to biological agents are the same as
for any infectious disease. It is important
for you to pay attention to official
instructions via radio, television, and
emergency alert systems.
HEPA filters are useful in biological
attacks. If you have a central heating
and cooling system in your home with
a HEPA filter, leave it on if it is running
or turn the fan on if it is not running.
Moving the air in the house through the
filter will help remove the agents from
the air. If you
have a portable HEPA filter, take it
with you to the internal room where you
are seeking shelter and turn it on.
If you are in an apartment or office
building that has a modern, central heating
and cooling system, the system’s
filtration should provide a relatively
safe level of protection from outside biological
contaminants. HEPA filters will not filter