Biological agents are divided into two categories: Pathogens and toxins.
Pathogens are living microorganisms that cause disease in man, animals, or plants. Pathogens produce
disease or infection by entering the body through the lungs, digestive tract, and through breaks in the
skin and mucous membranes of body openings. Then they reproduce to overcome the body's defenses,
thus causing disease. Microorganisms that can be used in biological warfare include: Bacteria, viruses,
Toxins are poisonous substances produced as by-products of pathogens or microorganisms, plants, and
animals. Some toxins can be chemically synthesized, and some can be artificially produced with
bioengineering techniques. Toxins exert their lethal or incapacitating effects by interfering with certain
cell and tissue functions.
There are toxins that disrupt nerve impulses or neurotoxins, and toxins that destroy cells by disrupting
cell respiration and metabolism or cytotoxins. There is a vast range of symptoms with both types.
These can be confused with both chemical and pathogen symptoms. Toxins are thousands of times
more toxic than nerve agents. This enables toxins to exert their effect, even though diluted by extensive
downwind or downstream travel.
Biological agents can cover an area larger than all other weapons. Large quantities of food, equipment,
and supplies can be contaminated by a single biological attack. The effects of biological agents can be
non-destructive, delayed, pervasive, and vary in severity.
Since biological agents, other than anti-materiel agents, affect only living things, equipment, facilities,
and structures will be left intact after a biological attack has occurred. In addition, biological explosive
not of sufficient force to produce any significant destruction. Spray weapons systems are completely
non-destructive. Biological agents do not cause casualties immediately. Time is required for the agent
to multiply. After the microorganisms have multiplied in sufficient quantity in the body, they may
overcome the body's defenses and cause disease. There is a period of time between the time of entry of
microorganisms into the body and the time the soldier actually becomes sick or becomes a casualty.
This period of time-to-casualty may differ for each agent and can vary from a few days to a few weeks
Effects may be either lethal or non-lethal, incapacitating. Lethal or killing agents can produce death, but
from a practical standpoint, death occurs only in a certain percentage of those