Warzone essentials: nerve gases

SCIENCE FOR YOUTH

by Hiya Islam

scienceNERVE agents or gases are a group of synthetic chemicals that are classed under ‘organophosphates’. While there are many such agents, most common ones include sarin, tabun, soman and VX. These straightaway target the nervous system in humans. Such an aim has proven truly efficient in killing. But before getting into the depths of the death mechanism, let’s break down the nervous system a bit.

The nervous system is formed by an intricate mess of nerves running to and from the brain and the spine. A nerve is essentially a bundle of cells called neurons which specialise in impulse transmission. A nerve impulse, again, is an electrical signal that is used in the communication between different organs of the body. Starting with the simplest actions like, breathing, muscle contraction or movement to the unseen, digestion in the gut, control of heart rate and what not, all these changes are carefully regulated by the nervous system and often with the aid of a cluster of hormones. Neurotransmitters are chemical carriers of information. Their presence serves to transmit electrical signals from one neuron to another via synapse (a junction between 2 neurons). As long as these are secreted, signals to produce a specified response will be generated. Therefore, to prevent overstimulation of neurons and unnecessary response neurotransmitter-degrading enzymes are kept in place. One such enzyme is the acetylcholinesterase (AChE); it breaks down acetylcholine. Nerve agents here play the evil role of binding into the enzymes. Consequently, acetylcholine accumulates in the synapses and continues to trigger action potentials.

The cold-blooded chemical bomb attack that killed hundreds of Syrians on April 2017 was due to sarin. Being odorless has made it a heinous tool for committing war crimes. A mere contact with the skin or eyes is sufficient to bring in the crippling effects. The symptoms will vary on severity depending on the dose and time of exposure. The results that follow are extremely upsetting. The whole body loses control over itself and suffers tormenting pain. The pupils constrict to a pinpoint and the chest tightens. The body begins to blatantly ‘let it all out’; AChE in fluid-producing glands is blocked. Incontinence, drooling and excessive sweating occur. Limbs convulse rapidly. Uncontrollable muscle contractions hardly allow any scope for breathing leading to death by asphyxiation.

Once exposed to these noxious gases, decontamination is mandatory for survival. Washing the skin with soap and water, rinsing the eyes and mouth and removing clothing are a few preliminary steps. Antidotes are administered to fight the symptoms. However, this should be done within 10 minutes of exposure to be effective. Atropine blocks acetylcholine receptors so that the chemicals can no longer bind to it and trigger nearby neurons. On the other hand, pralidoxime engages in the removal of sarin from the enzyme.

With the power of intelligence bestowed on man, he has made quantum leaps of progress over time. Among his tonnes of inventions and wonderful discoveries, there are works which should have never been acknowledged. To name one such creation is the nerve gas that is considered to be a weapon of mass destruction and is currently banned under international law.

 

Hiya Islam is a student of BRAC University.

 

 

 

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