Potential actions by terrorist groups span the NBC (nuclear, biological, chemical) threat spectrum. This topic discusses chemical warfare and chemical terrorism and reviews the medical aspects of detecting, diagnosing, and treating patients exposed to the chemical agents that are most likely to be used by terrorists as well as the appropriate initial actions to be taken by those exposed to such agents. Nuclear terrorism is beyond the scope of this topic, but practical information can be found elsewhere [1,2]. Bioterrorism is reviewed separately. (See "Identifying and managing casualties of biological terrorism".)
The word terrorism was first used to describe the post-revolutionary French "reign of terror" of 1793 to 1794. The term is now applied to NBC releases and other actions that violate international law, and which seek to intimidate, demoralize, or subjugate a population for political, religious, or ideological purposes. The use of biological and chemical weapons violates international law and is governed by treaties administered by the United Nations (UN). The biological weapons treaty was opened for signature in April 1972 and went into force in March 1975. The chemical weapons treaty was adopted in Geneva in September 1992 and went into force in April 1997. The Chemical Weapons Convention is administered in The Hague, Netherlands.
Research into biologic markers of exposure to chemical weapons is making steady progress and is important because of the need for rapid and reliable diagnosis of the chemical agents used in a terrorist attack, the need to confirm nonexposure for worried individuals, and the ability to document noncompliance with the UN Chemical Weapons Convention treaty .
- In 423 BC, a toxic smoke (sulfur and pitch) was used by the Spartan allies in the Peloponnesian War to force their enemies to abandon a fortification.
- The first modern use of chemical warfare (CWF) was on April 22, 1915 near Ypres, Belgium, where the Germans dispersed 150 tons of chlorine gas from about 6000 cylinders, generating 5000 pulmonary casualties among the 15,000 Allied troops on the battlefield.
- Sarin, the prototypical nerve agent and most significant current chemical terror threat, was synthesized in 1937 by Dr Gerhard Schrader of IG Farbenindustrie, Leverkusen Germany as part of the Nazi preparations for World War II. However, nerve agents were not used against the Allies because of fear of retaliation in kind.
- In 1983 Iraq used tabun against Iran, and Iran responded with a nerve agent of unidentified type. This exchange generated at least 10,000 deaths and casualties in the two armies.
- On March 16,1988, Iraq launched an attack on the Kurd population of Halabja, Iraq where there were 5000 deaths and a high number of casualties from both sarin and from sulfur mustard.
- A 1995 Tokyo subway attack by the religious cult Aum Shinrykio utilized sarin and caused 12 deaths and 5000 casualties . One year earlier, the cult had conducted a test attack on an apartment building in Japan and killed seven people.
TYPES OF CHEMICAL AGENTS
Nerve agents, toxic asphyxiants, pulmonary irritants, and blistering agents are the major types of chemical weapons potentially available to terrorists.