SciTech

How Things Work: Chemical Warfare

It is conventional to imagine a war consisting of battlefields laden with explosives, firearms, and missiles. More recently, however, terrorists and offensive armies have turned to chemical terrorism, as evidenced by the attacks in Syria this past summer. How do these terroristic agents affect the body?

Chemical terrorism is a method of attack that involves the intentional release of manufactured, extremely potent toxic chemicals. The most effective modern chemical weapons rely on agents with high killing power — those that can exterminate the largest population with minimal chemical concentration. Oddly enough, there is a large overlap between the chemicals used in warfare and in insecticides.

It is common to picture chemical weapons on a large, extravagant scale, such as the bomb in an action movie that discharges devastating chemicals above an unsuspecting metropolis. But as early as 1995, something as inconspicuous as an exploding canister has been used as a toxic gas release. That year, Aum Shinrikyo — a religious terrorist group in Japan — used a small, explosive canister to release sarin gas in the Tokyo subway, killing 13 and wounding thousands. Thus, even without the presence of nuclear bombs or similar explosive devices, chemical agents should be considered weapons of mass destruction.

From least to most aggressive, the most typically dreaded chemcial agents are sarin, cyclosarin, soman, VX, and novichoks, according to howstuffworks.com.

Sarin is a nerve agent that inhibits the cholinesterase enzyme, which nerve cells use to break down acetylcholine. Acetylcholine communicates between nerve cells and tells muscles to contract. Muscles lacking cholinesterase cannot clear the acetylcholine messengers, so they begin to contract uncontrollably. This eventually leads to death by suffocation, since the muscular diaphragm is incapacitated. With an acting time of five to 12 hours, sarin works fairly quickly and is relatively easy to manufacture.

Cyclosarin is also a nerve agent, working identically to sarin with double the toxicity. For example, if a person was stuck in a cubic-meter-large closet containing a mere 35 milligrams of airborne cyclosarin, they would be killed within one minute.

Soman, also similar to sarin, acts even faster. Depending on the dosage, which is nearly as toxic as cyclosarin, soman kills in a time between 40 seconds and 10 minutes.
VX operates identically to sarin and is 10 times more potent — just 10 milligrams exposure to the skin can kill a person. The primary difference between them is that VX is a liquid, whereas sarin is gaseous.

Novichoks are toxic nerve agents manufactured from the mixture of two otherwise ordinary chemicals. At least three novichoks existed as of 1990, but the extent to which the quantity has changed since then is largely unknown. Every novichok agent is more lethal than VX by up to 10 times. Novichoks are especially dangerous because their inner workings are not well understood, which may render current antidotes useless.

Chemical agents that do not attack the nerves can have less extreme effects. For example, if an offender were to use blistering agents like mustard gas, victims may suffer blistered skin and destroyed lung tissue but would risk death less than with nerve agents.

Chemical weapons are more intimidating than traditional weapons, since soldiers and civilians have a more difficult time protecting themselves. When chemical attack is judged a possibility on the battlefield, soldiers guard themselves with gas masks and total skin coverings. However, chemical attacks can come without warning, and civilians can be left vulnerable to the devastation. Due to their catastrophic effects, chemical weapons were prohibited by the Geneva Convention of 1925. Still, trespasses of the provision continue to be a major threat around the world.