Nerve agent
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Nerve agents are highly toxic chemical agents that poison the nervous system and disrupt bodily functions that are vital to an individuals survival.
Poisoning by a nerve agent leads to contraction of pupils, profuse salivation, convulsions, involuntary urination and defecation, and eventual death by asphyxiation as control is lost over respiratory muscles. Nerve agents can be absorbed through the skin, requiring that those likely to be subjected to such agents wear a full body suit in addition to a gas mask.
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Classes
There are five major substances that are classified as nerve agents. These for nerve agents are broken up into two main groups: the "G" agents and the "V" agents. The "G" agents are tabun, soman, sarin, and Cyclohexyl methylphosphonofluridate (GF). The "V" agent is typified by the agent known as VX.
Mechanism of action
The color of nerve agents depends on if it is in a pure state (colorless) or an impure state (yellowish). Some of the nerve agents have a slightly fruity odor to them. In general the nerve agents are somewhat soluble in water, but they have a slow hydrolysis. The nerve agents also are slightly soluble in lipids and are rapidly inactivated by strong alkalis and chlorinating compounds.
A technology associated with nerve agents is binary weapons technology. In this technology (as discussed in the Chemical Weapons General History section) nerve agents are mixture in a container (a missile, bomb, etc.) just before being dispersed.
Because the nerve agents are so much alike the majority of the information provided about the blistering agents will be contained in the above paragraph and the following sections nerve agents in general. However, small portions of differences between the nerve agents will be noted under the respective nerve agent.
A distinctive characteristics of the nerve agents is their high toxicity levels and their rapid effect on an exposed individual. Nerve agents (whether as a gas, aerosol, or liquid) enter the body through inhalation, through the skin, or through digestion. The time that it takes for a nerve agent to begin working is dependant mainly on the route that the agent enters the body. Generally poisoning occurs faster if it enters through the lungs (because of the ability of the agent to rapidly diffuse throughout the body from here). Nerve agents that enter through the skin may take slightly longer to kick in because they have to penetrate to the blood vessels.
Overall what happens when a person is exposed to a nerve agent is that upon entering the body, the nerve agent inhibits the normal actions of acetylcholinesterase; a chemical within the body whose normal function it is to break down the chemical acetylcholine, which cause muscular contraction. What nerve agents to acetylcholinesterase is to inhibit it from breaking down acetylcholine which in turn causes violent muscle spasms.
Symptoms
When an individual is exposed to low amounts of a nerve agent (as a gas or aerosol) the initial symptoms are a running nose, contraction of the pupils, visual accommodation deteriorates, headache, slurred speech, nausea, hallucinations, pronounced chest pains, and an increase in the production of saliva. At higher doses of a nerve agent the afore mentioned symptoms are more pronounced. Coughing and breathing problems also begin to occur. The individual then may begin to go into convulsions and a subsequent comatose and death. At doses even higher an exposed individual would almost immediately go into convulsions and die from suffocation because of the simultaneous shut-down of the nervous and respiratory systems. The initial stages of symptoms of an individual exposed to a nerve agent may vary depending on the particular agent and amount of the agent the person was exposed to.
Protection
A good source of protection from nerve agents, although not always useful, is a protective NBC (nuclear Biological Chemical) suit and a gas mask. It must be stressed that these protective articles of clothing do not always work against some nerve agents.
Treatment
Because nerve agents have a very rapid effect on an individual, if treatment is to work it must occur immediately after exposure or else death is certain to occur. A general antidote to nerve agents is a combination of atropine and a reactivator. Atropine protects against the excess of acetylcoline formed during nerve agent poisoning. The reactivator's job is to restore acetylcholinesterase to its normal functions. The degree of difficulty in combating the nerve agent depends greatly on what nerve agent is present.
The mixture of atropine and the reactivator is injected into an individual using what is know as an auto-injector. The auto-injector consist of the two active components which are injected into an exposed individual through the use of a very long needle. The auto-injector is usually injected into an individuals thigh or another area where the antidote can reach the heart relatively quickly.
References
- Borkin, Joseph (1978). The Crime and Punishment of IG Farben. Nw York: Free Press. 1978. ISBN 0029046300, available for download in Australia (as it is out-of-print) see this link (http://www.soilandhealth.org/copyform.asp?bookcode=030311).
- Template:Book reference
- E-Medicine. (June 29, 2004). CBRNE - Nerve Agents, V-series: Ve, Vg, Vm, Vx (http://www.emedicine.com/Emerg/topic899.htm). Retrieved Oct. 23, 2004.
- E-Medicine. (June 30, 2004). CBRNE - Nerve Agents, G-series: Tabun, Sarin, Soman (http://www.emedicine.com/emerg/topic898.htm). Retrieved Oct. 23, 2004.
- Mitretek Systems. (May 2004). Short History of the Development of Nerve Gases (http://www.mitretek.org/home.nsf/homelandsecurity/HistoryNerveGases). Retrieved Oct. 23, 2004.
- Paxman, J.; Harris, R. (2002). A Higher Form of Killing: The Secret History of Chemical and Biological Warfare (2002 Rando edition). Random House Press. ISBN 0812966538.
- United States Senate, 103d Congress, 2d Session. (May 25, 1994). The Riegle Report (http://www.gulfweb.org/bigdoc/report/riegle1.html). Retrieved Nov. 6, 2004.de:Nervenkampfstoff