Let's start with a chart showing a summary of the physical properties of key chemical agents:
Now let's look at the symptoms:
1.) Nerve Agents – pinpoint pupils, blurred vision heavy sweating and drooling, headache, drowsiness, nausea, respiratory distress, localized twitching and seizures, altered mental status. All nerve agents act by preventing the proper operation of an enzyme that acts as the body's off with for glands and muscles. Without this off switch, the body's glands and muscles are constantly being stimulated which eventually results in exhaustion and death.
a.) VX is among the most lethal of the nerve agents, causing severe disruption to the nervous system. VX was originally developed in the United Kingdom in the early 1950s. The only known use of VX is as a chemical warfare agent. A lethal dose of VX is slightly larger than the head of a pin. VX is odorless and tasteless and the liquid form is amber in colour with an oily consistency. It can remain in the environment for weeks to months since the oily form evaporates very slowly. It is denser than air and sinks into topographically low spots. Clothing provides little protection since VX can penetrate civilian clothing and be absorbed through any body surface. Gas masks protect only the lungs and eyes from VX.
In the case of VX, symptoms will occur within seconds of exposure and death can result within the same timeframe.
b.) Sarin is among the most quickly evaporating nerve agents. Sarin was developed in 1938 in Germany and was originally used as a pesticide. Exposure to even small doses of sarin can be lethal. It is odorless, tasteless and colorless and is heavier than air in gas form. It can penetrate clothing and be absorbed through any body surface. Gas masks protect only the lungs and eyes from Sarin. Sarin can also be absorbed through the ingesting of contaminated food or water.
In the case of Sarin, symptoms will occur within one minute of exposure.
One of the most recent uses of Sarin was a terrorist attack on Tokyo's subway system in March 1995 as shown here:
c.) Tabun (GA) is a tastless and colorless and tasteless liquid with a faint fruity smell that can become a vapor when heated. Tabun was developed as a pesticide in Germany in 1936. Tabun is also denser than air and sinks into topographically low areas. It also mixes easily with water so it can be used to contaminate a water supply. It breaks down slowly in the body; repeated exposures can have a cumulative effect. It can penetrate clothing and be absorbed through any body surface. Gas masks will protect only the lungs and eyes from Tabun.
In the case of Tabun, symptoms will occur within 2 to 5 minutes of exposure to the liquid form and within seconds to the vapor form.
The rate of symptoms for all nerve agents varies with the type of agent used; in the case of vapors, symptoms occur within seconds and minutes and in the case of liquids, symptoms occur up to 18 hours after exposure. A urine sample can define whether a person was exposed to a nerve agent.
2.) BZ (Incapacitating Agent) – severely altered mental status resulting in hallucinations and severe confusion, dilated pupils which create difficulty in seeing, dry eyes, mouth and skin due to diminished mucous secretion, impairment of vision, coma. This central nervous system depressant was developed following World War II after the United States military investigated the use of incapacitating agents. BZ or 3-quinuclidinyl benzilate was weaponized in the 1960s for possible battlefield use. BZ is colourless, tasteless and odorless and is not normally lethal but is incapacitating in even the smallest of doses. BZ will be absorbed by any body surface; gas masks will only protect the lungs and eyes.
In the case of BZ, symptoms will occur within one hour after exposure and last up to three days. Exposure to BZ can only be detected in urine. It is generally non-lethal in small doses.
3.) Mustard Gas – skin irritation and blisters, severe irritation of eyes, nose, mouth and throat, difficulty breathing which leads to pneumonia, abdominal pain, nausea and diarrhea. Mustard damages DNA, particularly in bone marrow causing decreased production of blood cells or decreased red or white blood cells and platelets. It was introduced in the First World War as a chemical warfare agent and was, at one time, used to treat psoriasis. Mustard is usually odorless but can smell like mustard, onions, horseradish or garlic. The gas form is usually yellow/brown in color and the liquid and solid forms are yellow or brown. The gas is heavier than air and sinks into topographically low spots. The gas is also carried easily by air currents and can remain in the environment for up to two days in warm weather and a week in colder climates. It is rarely deadly to healthy individuals but it can cause death in victims with poor health. Mustard will be absorbed by any body surface and can penetrate clothing. Gas masks protect only the lungs and eyes.
Here is are photos showing mustard gas blisters and eye irritation:
In the case of mustard gas, symptoms occur within 2 to 24 hours after exposure. Exposure to mustard can be detected in urine. If the person exposed to mustard is decontaminated using soapy water within two minutes of exposure, blisters will not form. It is rarely fatal; in the First World War, it killed less than 5 percent of those exposed.
While I was researching this posting, I wondered – what kind of mind would spend his or her days, developing chemicals and means of delivering those chemicals that clearly have no other purpose than to inflict deadly harm to another human being and what kind of a government, now or in the past, would continue to fund that development, particularly when it became very clear what level of pain its use could inflict?