THE
P RTAL
April 2018
Page 17
Nerve agents
Dr Simon Cotton is an Honorary Senior Lecturer in Chemistry at
the University of Birmingham and a member of the Ordinariate
N
erve agents are currently in the news, following reports that two people are in a critical
condition in a Salisbury hospital following exposure to a nerve agent, with others injured. But what are
they and how do they work?
The first nerve agents were invented by accident
in the 1930s, by researchers trying to make cheaper
and better alternatives to nicotine as insecticides.
A German industrial chemist named Gerhard
Schrader made some phosphorus-containing organic
compounds that were great at killing insect pests but
were too toxic to be used near humans.
The Wehrmacht found out about these compounds,
one of which we know now as sarin, investigated them,
and began constructing plants to manufacture them as
weapons. The sarin plant was not operational by the
time that the Russians overran Poland and Germany
(thereby acquiring a chemical warfare capability).
VX was discovered in 1952 by British chemists,
again trying to make insecticides – this research was
eventually handed over to the Americans, who started
to manufacture it in the 1960s.
One accident during testing in Utah killed
several thousand sheep. The so-called ‘Novichok’
(‘Newcomer’) agents – one of these is believed to have
been used in Salisbury - were developed by Russian
researchers in the 1940s and 1950. Most nerve agents
are liquids, but some Novichok agents are thought to
be solids.
Unlike street drugs, nerve agents cannot be made
in your kitchen or garden shed, because they are
incredibly toxic. Lethal doses involve milligrams, or
less. Making them requires a specialist laboratory,
with fume cupboards. Workers would have to wear
incredible protective clothing, because nerve agents
are also absorbed through the skin; when the Nazis
were building their first nerve agent plant, workers
wearing protective suits died in agony when nerve
agent got through gaps in the suits. Decontamination
can be a problem.
be a dangerous build-up; it uses an enzyme called
acetylcholinesterase (AChE) to do that. A nerve agent
stops acetylcholinesterase from doing its job.
As far as is known, nerve agents were not employed
until the 1980s. Saddam Hussein’s Iraqi forces are
thought to have used sarin during the Iran-Iraq war,
notably against Kurdish citizens in Halabja on 16–17
March 1988, leaving about 5,000 dead. On 20 March
1995, members of the Japanese Aum Shinrikyo cult
used umbrellas with sharpened tips to puncture
plastic bags and boxes containing sarin while they
were travelling on the Tokyo subway system. 13 people
died. VX has been used more rarely, most recently in
killing Kim Jong Nam, the half-brother of King Jong
Un, North Korea’s leader, allegedly by smearing VX
nerve agent across his face in an airport in Kuala
Lumpur on February 13 th 2017.
Salisbury is believed to be the first time that a
Novichok agent has been used ‘in public’.
Unlike traditional poisons, nerve agents don’t need
to be added to food and drink to be effective. They can
be inhaled or absorbed through the skin. Symptoms
of nerve agent poisoning come on quickly - usually
in a minute or less - like chest tightening, difficulty
Nerve agents disrupt the central nervous system. The in breathing, and very likely asphyxiation. Associated
body uses a ‘messenger molecule’ called acetylcholine symptoms include vomiting and massive incontinence.
to send messages between cells; when an acetylcholine
Antidotes exist, one being atropine, but they have
molecule ‘arrives’ it causes an electrical impulse to
be sent. The body has to remove those acetylcholine to be administered quickly, otherwise the effect of the
molecules from the receptors, otherwise there would nerve agent cannot be reversed.