HISTORY
Biological warfare has become a very real possibility since World War II because of the advance of knowledge in the various biological science fields. Many countries have indulged in research on the use of microorganisms as a weapon of war, and in the hands of an unscrupulous enemy, antianimal and antiplant agents could be powerful instruments of war, reducing or destroying a nation's food supply. In this chapter, however, we are concerned only with agents that would be effective against populations. Although their effectiveness has never been established by actual use in war, they are considered to have grave military capabilities.

DISPERSAL
Biological warfare has certain aspects in common with chemical warfare in that biological agents can be dispersed in the air and travel downwind in the same manner as a gas cloud. These agents may be inhaled unless a protective mask is worn, and they may cause disability or death. They are capable of contaminating clothing, equipment, food, and water supplies. Some types of agents may persist in the target area for considerable periods of time.

Biological agents, unlike most war gases or vapors, cannot be detected by the physical senses or by chemical detectors. Their presence or identity can be determined only by laboratory examination of air samples or contaminated objects. The time between exposure and onset of disease symptoms will usually be a matter of days rather than hours, as is the case with most chemical agents. Though they may be exposed to the same dosage of biological agent, not all personnel will be affected the same way. Some may become seriously ill, while others may have a very mild attack. Still others may escape the disease entirely.

PROTECTION
In this section, we will discuss both individual and group protection, as well as the methods of protecting food and water supplies.

Individual Protection
The natural resistance of the body and its maintenance in the best possible physical condition constitute important lines of defense against biological agents. Immunity and good health alone, however, cannot be expected to triumph over massive onslaughts of biological agents. These agents may have been tailored to create varying degrees of incapacitation, including death. To reduce the effectiveness of such attacks, the military provides protective equipment and a series of protocols to its members. In general, these measures closely parallel those provided for defense against chemical attack.

PORTALS OF ENTRY.-Inhalation of airborne organisms is considered the greatest potential hazard in biological warfare. The protective mask is an important piece of defensive equipment. A mask that is in good condition and has been properly fitted will greatly reduce the possibility of your inhaling infectious material. Since you cannot detect the presence of biological agents, the use of the mask and other protective equipment will depend upon early warning.

To produce disease, biological agents must gain entrance into the body. A concentration of biological agents on the skin might, in time, be transferred to a portal of entry. Any type of clothing will provide some protection by reducing the quantity of agents coming in contact with the skin. The degree of protection afforded is dependent upon how well the fabric stops penetration and the number of layers of clothing being worn. Since this protective effect is due to the mechanical filtering or screening action of the cloth, it is important that shirt and jacket collars be fastened. Sleeves should be rolled down and cuffs buttoned, trouser cuffs stuffed inside tops of boots or socks, and all other garment openings tied or otherwise secured. Following this procedure will minimize the entry of airborne organisms and reduce the risk of bodily contact with biological agents that may be present on the surface of the ground or in the air.

EQUIPMENT AND ACTION.-Military headgear helps safeguard the hair from heavy contamination, and ordinary gloves or mittens provide protection for the hands. The type of clothing issued for protection against chemical agents is impregnated with an impermeable barrier and provides a higher degree of protection than the ordinary uniform. Whenever it is available, it should be used.

Upon notification of an attack with biological agents, or before entering an area known to be contaminated by them, the following steps should be taken:

1. Put on protective mask and check it for correct fit.

2. Button clothing. Tie clothing at wrists and ankles with string or extra shoelaces. Put on special protective clothing, if available.

3. Put on gloves, if available.
4. While in the contaminated area, maintain the provisions outlined above.

Upon leaving the area, proceed with decontamination measures to the extent the situation permits.

Group Protection
In biological as well as chemical and radiological warfare, a tightly constructed shelter offers great protection. The shelter must be pressurized to prevent entrance of the microorganisms. Pressurization is accomplished by introducing filtered air into the shelter. If the shelter is reasonably tight, this incoming air will force exhausted and/or contaminated air outward. Nonpressurized buildings, shelters, or field fortifications provide only limited protection from aerosols. Eventually, microorganisms will penetrate through cracks, creating a respiratory hazard requiring the use of a protective mask. As in the case of other protective equipment, the sooner a shelter is used following contamination, the more effective the shelter will be in arresting or staying in contact with biological agents.