Chemical terrorism agents can be poisonous vapors, aerosols, liquids or solids that have toxic effects on people. These chemicals are usually manmade but can also naturally occur in the environment. Chemical exposures can be unintentional, such as an industrial accident, or intentional, as in the case of a terrorist attack. The early detection and correct identification of chemical agents is critical to enable effective treatment and to prevent additional exposures.
Chemical agents can be deadly, are easy to distribute, and are relatively inexpensive to produce. Terrorists actively seek these agents due to the tremendous psychological impact their real or perceived use can have on the public.
These agents have been used in war since the time of the ancient Greeks. However, they gained international attention during World War I as various chemical gases were extensively used against the enemy in opposing trenches. More recently, there has been a resurgence of use in such places as Syria and Iraq; in 2017 and 2018 nerve agents were used in foreign political assassinations.
Chemical terrorism agents can be coated onto everyday items or dispersed into the air as an aerosol as occurred in Japan. In 1994 and 1995, the terrorist cult Aum Shinrikyo released a crude form of sarin nerve gas into the air in two Japanese cities, which resulted in 19 deaths and over one thousand people injured. Most of the injuries were due to the panic that ensued after the attack.
Chemical agents normally cause a small number of deaths each year. They can enter the body by inhalation into the lungs, ingestion through food and water, absorption through the skin, or by contact with the mucous membranes of the eyes and nose.