The chemical bomb attack that killed at least 86
people, including 28 children, in Syria on April 4 likely involved sarin, a
deadly nerve agent.
Sarin is a highly poisonous chemical that kills
because it interferes with signaling within the nervous system. Here is the
science behind this deadly gas.
In its liquid form, sarin is clear, colorless,
odorless and tasteless. The liquid form of sarin can evaporate into a vapor,
which people may then breathe in. During the attack in Syria on April 4, the
chemical was spread during a bomb attack, according to news sources.
Like other nerve agents, sarin targets an enzyme
within the body's neuromuscular junctions, where nerves meet muscles. Usually,
this enzyme deactivates the nerve-signaling molecule acetylcholine. But sarin
stops this deactivation by blocking the enzyme. Without the enzyme to switch it
off, acetylcholine will repeatedly stimulate nerve cell receptors. This can
lead acetylcholine to build up in the muscles, cause excessive twitching and
then result in paralysis, said Dr. Lewis Nelson, chairman of emergency medicine
at Rutgers New Jersey Medical School. If the muscles that control breathing
become paralyzed, the person can die, he said.
Organophosphate pesticides and nerve agents can
also target the same enzyme in glands, which can lead to excessive fluid
release. For this reason, people who are exposed to sarin, whether through
skin-to-skin contact or inhalation, may experience diarrhea, along with excess
fluids running from their eyes, noses, mouths, sweat glands and urinary tract.
People who are exposed to sarin may also experience seizures and pinpoint
(constricted) pupils
Sarin can cause symptoms within seconds to minutes,
depending on its route and exposure levels.
People who are exposed to sarin should quickly
decontaminate themselves by removing their clothing and washing their skin with
soap and water, Nelson said. They should also flush out their mouth and eyes
with water.
People who become paralyzed may benefit from an
oxygen mask attached to a device that will help them breathe. But sarin affects
so many of the body's organs that, usually, an antidote is needed to help
people who are exposed to it live.
One antidote, atropine, blocks acetylcholine
receptors, sparing the body's muscles from overstimulation. The other,
pralidoxime, or 2-PAM, removes sarin from the enzyme that stops acetylcholine
from accumulating, Nelson said. However, both antidotes must be given within
about 10 minutes of exposure in order to be effective, he said.
Sarin and other nerve agents are banned under the
Chemical Weapons Convention. More than 190 counties worldwide participate in
the convention.
To date, nearly 95 percent of declared
chemical-weapon stockpiles in countries participating in the convention have
been destroyed, according to the Organisation for the Prohibition of Chemical
Weapons, which enforces the rules of the convention.
A deadly attack on the Tokyo subway in 1995 made
sarin one of the best-known nerve agents in the world.
Members of the doomsday cult Aum Shinrikyo used
sarin in their attacks. Their first victims died in 1994, when the cult
poisoned people in Matsumoto, Japan. These people happened to be living near
three judges who were overseeing a lawsuit that involved the cult. Later, in
1995, Aum Shinrikyo members filled plastic bags with liquid sarin and placed
them under the seats of Tokyo subway cars. The perpetrators punctured the bags
and then exited the trains.
The subway attacks resulted in 13 deaths and
injured at least 5,500 people, news sources reported.
Syria had used sarin as a weapon prior to the April
2017 attack. In 2013, the Syrian government reportedly used the gas in the
suburbs of Damascus, killing more than 1,000 people, according to The New York
Times.
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