Liquid exposure, nerve agent

Nerve Agents are the most toxic of the known chemical agents. Solids, liquids or vapors from these agents are hazardous and can cause death within minutes after exposure. Nerve Agents disrupt the function of the nervous system by interfering with the enzyme acetylcholinesterase. The major effects will be on skeletal muscles, certain organs, and the central nervous system. These compounds are similar to, but much more deadly than, agricultural carbamate pesticides. 

Symptoms appear much more slowly from skin absorption. Skin absorption great enough to cause death may occur in 1-2 h. Respiratory lethal dosages kill in 1-10 min, and liquid in the eye kills nearly as rapidly. Very small skin dosages sometimes cause local sweating and tremors but little other effects. Nerve agents are cumulative poisons. Repeated exposure to low concentrations, if not too far apart, will produce symptoms. 

Typically, there is a latent period with no visible effects between the time of exposure and the sudden onset of symptoms. This latency can range from 1 minutes to 18 hours and is affected by such factors as the amount of agent involved, the amount of skin surface in contact with the agent, and the area of the body exposed (see Liquids). Moist, sweaty areas of the body are more susceptible to percutaneous penetration by solid nerve agents. 

It is unlikely that the unchanged nerve agent would be detected in the blood or tissues of a casualty unless samples were collected very soon after the exposure. A number of methods have been reported for the analysis of nerve agents in blood, for application to animal studies. These involve simple liquid or SPE extraction, for example, using chloroform (sarin, soman) (47), C18 SPE (sarin, soman) l48 49 , ethyl acetate (VX) (50), usually after precipitation of proteins, and analysis by GC/MS or gas chromatography/nitrogen-phosphorus detection (GC/NPD). Sarin bound to cholinesterase and displaced with fluoride ion was extracted by C18 SPE (see Part B) (51). 

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