Alpha radiation becomes a hazard only if alpha- emitting contaminants are taken into the body by breathing, eating, drinking, or by absorption into the bloodstream through broken skin. Major alpha contamination in a nuclear attack is not likely; however, it will present a hazard in the event of a nuclear weapons handling accident. BETA . —Beta radiation has a range in the air of only a few feet and has limited penetrating power. Generally, you cannot stop beta radiation with light-porous material, such as ordinary clothing, particularly since the contaminant tends to impregnate the material. However, you can stop beta radiation with dense material, such as heavy-duty gloves and foul-weather clothing. Beta contamination is primarily a skin-contact hazard. GAMMA. —Gamma radiation is similar to X radiation (X rays). It has an effective range in the air of many hundreds of feet and is highly penetrating. It cannot be completely stopped by a barrier. A sufficient thickness of material can reduce the intensity of gamma radiation to an insignificant level. Because of the penetrating power of gamma radiation and the large amount of gamma rays emitted by fallout contaminants, it is the most significant radiation hazard in most contaminated ship situations. CHEMICAL AND BIOLOGICAL DEFENSE The threat of attack with chemical or bio- logical warfare agents is more likely on land. However, their uses are still a definite threat in naval engagements and amphibious operations. BIOLOGICAL WARFARE (BW) Large-scale use of biological warfare (BW) agents has not occurred in modern times. Therefore, there is little experience with the military potential of BW agents except by noting that naturally occurring diseases have affected the outcome of some past wars. Any nation with a modern scientific program can produce effective biological agents. Biological warfare is the intentional use of living infectious microorganisms (germs) to reduce or destroy the military effectiveness of personnel. The exception to this is the recent use in Southeast Asia and Afghanistan of toxins classified as BW agents but are not living organisms. BW agents are living microorganisms (except toxins) that cause disease in personnel, plants, and animals. BW agents differ greatly from chemical agents in that a living microorganism can grow and multiply in a susceptible host. Once infected, an incubation period is required before the infection produces a casualty. This incubation period varies greatly among infectious microorganisms. For this reason, use of BW agents are unlikely to be used in situations where results are needed in less than 48 to 72 hours. Detection and Identification Because of the incubation period, there is a lapse of time before victims realize they are infected. Detection before the first symptoms are noticed is difficult, and identification of a particular agent may take considerable time. It is possible to detect excessive organic life in the atmosphere, but identification of the particular agent is still in the development stage. Once a biological infection is started, it may spread by normal contagious processes without further agent deployment. BW agents will infect an individual if they enter the lungs, stomach, or bloodstream. Dissemination BW agents are likely to be dispersed as aerosols of solid or liquid particles and are invisible except near the source of dissemination. These particles, when inhaled, can penetrate the lungs where they can start an infection. Aerosols of BW agents can penetrate buildings and ships. The microorganisms required to infect an in- dividual are so small that it is possible for a single delivery vehicle to spread a casualty-producing aerosol over many hundreds of square miles. When biological agents infect biting flies, mosquitoes, fleas, and ticks and are released into an area, they, in turn, bite and infect people. BW agents may also be spread by saboteurs, who may contaminate food and water supplies, food processing plants, and air- conditioning systems. Shells, rockets, and mortar bombs are not suitable for dissemination of these agents because of the adverse effect of heat and shock in an explosion. Self-Aid If you suspect that BW contamination has taken place, put on your protective mask and observe the basic principles of preventive 7-24