Chemical Warfare Symbol

Chemical Warfare Symbol

When you learn disaster medicine, they teach you bad things that terrorists could do. From the medical perspective, this means fun topics like explosion injuries, nuclear or radiation exposure, biologic agents like anthrax, plague, or smallpox, and chemical warfare agents. After a day of training, you go home feeling a bit paranoid. Even if you believe Homeland Security is protecting us, don’t forget industrial or transportation accidents. After all, bad things are made and stored somewhere. The nuclear disaster after the 2011 Japanese earthquake is a great example.

Sarin – Nerve Agent for Chemical Warfare

Of all the threats, chemical weapons freak me the most, particularly the “nerve agents’. This week, my fear notched upward with the news that Syria may be loading sarin in bombs. We’ve seen sarin before – it was the agent in the Japan subway attacks of 1995, which killed 13 and injured almost 1000. Hospitals treated over 5500 patients, many of whom were “worried well”. The only upsides of the Japan attack were:

  1. The sarin distribution method used by the cult was inefficient, or it would have been much worse.
  2. Emergency responders learned many lessons  –  like quickly recognizing chemical attacks, decontaminating patients before hospital entrance, and dealing with massive numbers of casualties.

Nerve agents are just strong pesticides, in the same class as malathion. They are also known as organophosphates based on their chemical structure or anticholinesterases based on their action (just to confuse you). They prevent muscles from relaxing, leading to uncontrolled muscle contractions. They cause massive amounts of secretions and spasm of the airways. The mnemonic DUMBELS helps physicians remember clues for diagnosing organophophate poisoning. Unfortunately, it’s in medicalese, so here is my interpretation:

Nerve Agent poisoning symptoms

Mnemonic for nerve agent poisoning.

With enough insecticide exposure,  both insects and humans develop symptoms, and if not treated, they will die. In third world countries, insecticides are actually the most common method of suicide. The difference between insecticides and nerve agents is really just potency. It takes only one small drop of sarin on your skin to kill you, although it may take an hour or so.  If inhaled or ingested, you die in minutes. An aerosol (in a bomb) is more deadly than the liquid form (Japan subway), although even liquid sarin vaporizes quickly, and still sickens most people by inhalation. Sarin is 26 times more deadly than cyanide.

Scared yet? Sarin is not even the worse drug on the nerve agent list. Sarin and other nerve agents in the “G class” only stick around for hours to a few days, and can be washed off. The “V class” nerve agents are 10 times more deadly than sarin. They do not degrade, so they poison an area for weeks or months. They are oily and difficult to clean off skin or objects. Luckily ruining an area for months is usually not a political goal.

Nerve Agent Symptoms

Remove clothes in sarin attack

This is probably taking the concept of stripping, getting upwind, and avoiding low-lying areas a little too literally!
Photo by Phil Robinson.

Should you be unfortunate enough to contact a nerve agent, you will not smell anything. It will  start with a runny nose and tightness in your chest, followed by nausea, drooling, and difficulty breathing. As the other

DUMBELS symptoms add on, there will be muscle jerking, seizures, and eventually death from breathing failure. Others around you will show similar symptoms – the clue to a chemical exposure! Unless you carry atropine and 2-PAM Cl syringes in your pocket, your best hope is fresh air. As soon as out of the contaminated area, strip off your clothes – not the time for modesty. If water is available (including fountains or hoses), rub and rinse yourself off. Haz-Mat emergency responders have complete decontamination equipment and initial medical treatment. If possible, wait for them. If you go to the hospital, remain outside and inform them of a possible chemical exposure, so they can decide on decontamination. Contaminating hospital and staff just makes assistance scarcer, for yourself and others.

Recognizing a Chemical Attack

How do you recognize a chemical attack from a distance? A group of people with watery eyes, twitching, choking, trouble breathing or poor coordination might be the first sign. If you see people down, or even dead animals, assume the worse. Despite an overwhelming desire to help, DO NOT ENTER THE AREA, even if a loved one needs you. You can not help! Call 911, then move upwind and avoid low lying areas (some nerve agents tend to sink). If inside a building with a chemical exposure outside, then stay inside! Move to an upstairs room as far away as possible from the source and close all windows and doors (we’ll talk more about shelter in place in a future post).

Now let’s put things back in perspective, so we can all sleep tonight. Nerve agents have been around since World War II, with stockpiles by most major countries (and obviously smaller countries as well). Despite this, only one incident of large scale nerve agent warfare occurred, by Iraq against the Kurds in the 1980s. The only major terrorist event was the Japan sarin attacks. Despite wide-spread availability, nerve agents are not the weapon of choice for a variety of logistical and political reasons. They are considered weapons of mass destruction, treaties ban their use, and other countries are likely to intervene if chemical weapons are used, even when they refuse to stop massive casualties from traditional weapons.

Chemical warfare suits

Protective suits with respirators required in a chemical contamination zone. I’ve worn one – they are horrible!
Photo by Ronoldson Slim

Hopefully the reluctance to use these agents will continue, but it doesn’t hurt to learn potential signs and symptoms of a nerve agent attack, just in case things worsen in the future. The Centers for Disease Control has Fact Sheets on Specific Chemical Agents , if you would like more information. Be prepared. Strip to save yourself!

Stay safe,

Sheila Sund, M.D.


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