Chemical and Biological Warfare, use of harmful or deadly chemical or biological agents as weapons of war. These agents can kill many people and are considered weapons of mass destruction. Chemical weapons are made up of poisonous chemical compounds, whereas biological weapons are living microorganisms. Toxin weapons contain poisonous chemical products of living organisms and are sometimes classified separately. Chemical and biological weapons can cause injury in several ways. Most cause injury or death when inhaled, and some cause injury through contact with skin or through ingestion of contaminated food.
A chemical or biological attack usually involves dispersing agents into the air. This can be done in various ways, such as firing artillery shells that burst in midair, or using airplanes to spray the agents over an area. If released outdoors, these types of weapons can be affected by weather conditions. Rain would reduce the effectiveness of the agents, and wind might spread them in unexpected directions. In the 20th century, chemicals were used extensively as battlefield weapons only in World War I and the Iran-Iraq War. The release of the nerve agent sarin in a Tokyo subway in 1995 was a rare terrorist chemical attack.…
