How Does Nerve Gas Impact the Human Nervous System?
A nerve gas or a nerve agent is used as an agent of chemical warfare to paralyze one's nervous system. These gases act as a poison for the nervous system as they are acetylcholinesterase inhibitors. Exposure to a mild or moderate amount of nerve gas can lead to severe symptoms. Exposure to a huge amount of gas or exposure for a long time may lead to death.
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Among nerve gases, the most widely-known ones are Soman, Sarin chemical, and Tabun, all developed in Germany during World War II. However, they were never used. On the other hand, newer nerve gases like VX had been developed during the Cold War but are now used in trace amounts in weapon-making. A nerve agent is usually a tasteless and colourless or amber-coloured liquid that can evaporate in the air easily. Soman has a light odour of camphor while Tabun has a light fruity odour and VX and Sarin is completely odourless.
Classes of Nerve Gas
There are mainly two classes or types of nerve agents. They are known as, G-series and V-series nerve gases.
G-Series
The G-series nerve gas was first synthesized before or during World War II. The nerve agents of the G-series were GA or Tabun, the GB or Sarin chemical, the GD or Soman, and lastly GF or Cyclosarin in 1936, 1939, 1944, and 1949 respectively. Out of them, only GB or Sarin has been consistently used by the USA while making artillery shells, aerial bombs, rockets, and munitions.
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V-Series
The V-series came next and is a much more persistent gas than the G-series ones. Their variants included the VX, VR, VM, VG, and VE. Out of these VX was the most well-known one. It was first utilized as a pesticide under the name Amiton but was withdrawn soon due to its toxic effects. The VX is also used by the USA in landmines, airplane spray tanks, artillery shells, and rockets.
Nerve Gas Effects
Nerve gas will attack your nervous system when it gets absorbed into your system through the bloodstream. Sarin gas effects include attacking the ACh which is responsible for controlling muscle tissues, paralyzing the muscles, and restricting their movement. This leads to more severe complications within seconds and in most cases, is followed by death.
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Initial symptoms of a nerve gas attack of Sarin include pupil constriction, tightness in the chest, runny nose. This is generally followed by salivation, nausea, and difficulty in breathing. One starts to lose control of their body which will be followed by muscle jerks and a type of epileptic seizure known as status epilepticus. If one has been exposed to a large amount of gas or has been exposed for a long time, one will die due to cardiac arrest or asphyxiation.
The first symptoms of a nerve gas attack will start appearing in 30 seconds leading to a massive cardiac arrest or asphyxiation (reduction in the supply of oxygen to lungs) leading to death. These nerve gas effects are severe and can last for a very long time. Every nerve gas attack survivor has suffered from psychiatric and neurological damage. Some Sarin gas effects stay for a long time and induce symptoms like tiredness, blurred vision, memory loss, eye strain, and others.
Method of Spreading
Nerve gas like Sarin nerve gas can spread through:
Aerosol munitions
Generation of smoke
Dissemination of explosives
Foggers, humidifiers, atomizers
How the nerve agent is spread depends on the properties of the nerve gas itself, the type of target, and how much the gas needs to be concealed.
Did You Know?
VX of the V-series nerve agent was first accidentally discovered by Ranajit Ghosh in Porton Down in the UK in the 1950s.
Nerve gas attack treatment includes oxime to be used as an antidote and anticholinergic to control the symptoms.
FAQs on Nerve Gas: Types, Mechanism of Action, and Biological Effects
1. What exactly are nerve gases, and can you provide some examples?
Nerve gases, also known as nerve agents, are a class of highly toxic organophosphorus chemical compounds. They are not necessarily gases at room temperature but can be dispersed as vapours or aerosols. Their primary function is to disrupt the chemical communication of the nervous system. The two main categories are:
G-series: These were the first nerve agents discovered in Germany. Examples include Tabun (GA), Sarin (GB), and Soman (GD).
V-series: These are more modern, persistent, and generally more toxic agents. The most well-known example is VX.
2. How do nerve agents work on a biological level to harm the body?
Nerve agents function by inhibiting a crucial enzyme called acetylcholinesterase (AChE). Normally, the neurotransmitter acetylcholine (ACh) sends signals to muscles and glands, and AChE then breaks it down to stop the signal. Nerve agents form a strong bond with AChE, preventing it from working. This leads to a massive buildup of ACh in the body, causing constant, uncontrolled stimulation of nerve receptors. This overstimulation results in muscle convulsions, glandular over-secretion, respiratory paralysis, and ultimately, death.
3. What are the immediate symptoms a person might experience upon exposure to nerve gas?
The symptoms of nerve gas exposure appear rapidly and affect multiple body systems due to widespread nervous system disruption. Immediate signs can include:
Eyes: Pinpoint pupils (miosis), blurred vision, eye pain.
Respiratory: Chest tightness, difficulty breathing, severe runny nose.
Gastrointestinal: Nausea, vomiting, abdominal cramps, drooling.
Muscular: Involuntary muscle twitching, weakness, leading to convulsions and paralysis.
Loss of consciousness and seizures often follow, with the primary cause of death being respiratory failure.
4. What is the difference between G-series and V-series nerve agents?
The primary differences between G-series (like Sarin) and V-series (like VX) agents lie in their potency and persistence.
Persistence: G-series agents are generally non-persistent, meaning they evaporate quickly and pose a short-term inhalation hazard. V-series agents are oily, low-volatility liquids that can persist on surfaces for days or weeks, acting as a long-term contact hazard through skin absorption.
Potency: V-series agents are significantly more potent than G-series agents. A tiny drop of VX absorbed through the skin can be lethal, whereas G-series agents typically require inhalation of a larger amount to be fatal.
5. What is the standard medical treatment for someone exposed to nerve gas?
Treatment for nerve gas poisoning is a time-critical, two-part intervention. The standard approach involves administering two types of drugs, often from a pre-filled auto-injector:
An anticholinergic drug, such as atropine, which works by blocking the acetylcholine receptors to counteract the effects of its excess in the body. This helps manage the symptoms like secretion and muscle spasms.
An oxime, such as pralidoxime (2-PAM), which works to reactivate the disabled acetylcholinesterase (AChE) enzyme by breaking the bond formed by the nerve agent. This must be administered quickly before the bond becomes permanent.
6. How were the first nerve agents like Sarin and Tabun discovered?
The first nerve agents were discovered by accident in Germany during the 1930s. A research team led by Dr. Gerhard Schrader was working to develop more effective insecticides. While synthesising new organophosphate compounds, his team created a substance in 1936 that was exceptionally toxic to mammals. This compound was later named Tabun (GA). In 1939, his team synthesised an even more potent compound, which became known as Sarin (GB). These discoveries shifted from agricultural research to military weaponisation during World War II.
7. Why are nerve agents considered far more dangerous than the insecticides they were originally related to?
The key reason lies in the nature and stability of the chemical bond they form with the acetylcholinesterase (AChE) enzyme. While many organophosphate insecticides also inhibit AChE, they often do so in a less potent or reversible manner. Military-grade nerve agents, however, form an extremely stable, essentially irreversible covalent bond with the enzyme’s active site. This process, known as 'aging', renders the enzyme permanently useless. This leads to a much more rapid, complete, and catastrophic shutdown of nervous system regulation than that caused by most commercial pesticides.
8. Is the use of chemical weapons like nerve gas regulated under international law?
Yes, the development, production, stockpiling, and use of nerve gases are strictly prohibited under international law. The primary treaty governing this is the Chemical Weapons Convention (CWC), which entered into force in 1997. Signatory nations are obligated to destroy any stockpiles of chemical weapons and are forbidden from using them in warfare. The Organisation for the Prohibition of Chemical Weapons (OPCW) is the international body responsible for implementing and verifying compliance with the CWC.
