Biological weapons are organisms or their by-products used to deliberately spread disease. They include bacteria, viruses, rickettsiae , protozoa , fungi , and their toxins. The effects of biological warfare agents are diverse, but they generally incapacitate or kill their victims, or destroy crops or livestock.
Biological weapons have been used for centuries. The Tartar army catapulted plague-ridden corpses over city walls in the 1346 siege of Kaffa. All major participants in World War II developed biological weapons, however Japan, which dropped bubonic plague–infested debris on Chinese cities, was the only country known to have used them. In 1969 the United States abandoned research and production of biological weapons. Within three years, remaining U.S. stockpiles were destroyed. In 1975, 118 countries signed the Biological Weapons Convention that outlawed the development, possession, and stockpiling of biological weapons.
Biological weapons are often called "the poor man's weapon of mass destruction" because they are cheap and easy to produce. The production processes used to make biological weapons are similar to those used to develop medicines or make yogurt. Since facilities, equipment, and supplies resemble those for biotechnical and medical research, they can be hidden within legitimate facilities, making it difficult to track development of biological weapons. Compared to chemical or nuclear weapons, biological weapons are easily handled and effective in small amounts.
Exposure to most biological weapons occurs by inhaling an aerosolized agent. The most difficult part of producing the weapon is getting the agent into a small, stable form for dispersal. Agents can be dispersed as part of a
There are more than sixty potential biological warfare agents. Two of the most common are anthrax and botulism. The anthrax bacteria, Bacillus anthracis, commonly cause disease in cattle, horses, and sheep. In humans, cutaneous anthrax, which causes skin ulcers, accounts for about 95 percent of U.S. cases, with little mortality. However, inhalation of anthrax spores destroys lung and intestinal membranes, causing severe respiratory distress, shock, and death in about five days. Although antibiotics can be used, the mortality rate for inhaled anthrax is nearly 100 percent after symptoms appear. Anthrax is easy to cultivate and forms highly resistant spores that can remain active and potentially lethal for at least forty years.
Botulism is caused by Clostridium botulinum neurotoxin. Inhaling a very small amount of this bacterial toxin blocks electrical signal transmission in the nervous system and causes progressive muscular paralysis. Paralysis of respiratory muscles leads to asphyxiation and death. Tracheostomy and use of a ventilator reduce mortality, but recovery may take months of intensive nursing care.
Advances in biotechnology may produce biological weapons that are even more toxic, fast acting, and resilient. Genetic engineering may produce new organisms or toxins designed to target specific populations. Cloning techniques may allow for mass production.
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Solomon, Brian, ed. Chemical and Biological Warfare. New York: H. W. Wilson Company, 1999.