Sarin was made famous by the attacks on the Tokyo subway by the lunatic religious cult Aum Shinrikyo in the mid 1990s. The fact that fatalities were relatively low does not reflect the toxicity of this nerve agent. Developed as a chemical weapon in WWII sarin is a deadly organophosphate also known as GB and is reputedly 26 times more deadly than cyanide.
The mode of action for all nerve agents is to prevent nerve endings from switching off. Death results from loss of control of the muscles required for breathing and asphyxiation. The immediate effects of the toxin are a loss of control of bodily functions. Convulsions follow along with coma and death within an hour.
Sarin is one of the “Killer B’s”, the symptoms of exposure to which are described in the mnemonic “SLUDGE” – Salivation, Lacrimation, Urination, Defecation, Gastrointestinal distress, and Emesis. Nice!
The United Kingdom can be proud to have developed what is the most potent nerve agent on Earth. So deadly was this toxin that they codenamed it “Purple Possum”! Unlike virtually every other poison on this list VX does not occur naturally, it is completely man-made and was developed to kill as effectively as possible. The good news is it was banned in 1993 meaning the USA have had to dump its stockpiles. Russia are meanwhile in the process.
Symptoms are as with sarin but VX is more potent. These may begin within seconds of exposure and death is likely to result from respiratory failure.
VX is the chemical that features in the 1996 film “The Rock” in which San Francisco is threatened with attack. It is also believed that VX was responsible for the deaths of 6,000 sheep in an incident known as the Skull Valley sheep kill in Utah near a US Army testing base.
3. Arrow poison frog
Primarily the batrachotoxin poisons from the skin of certain frog species has been used to coat the tips of hunting darts by certain Amazonian Indians. Given human nature, I imagine a few of these darts have ended up finding a human target with lethal effect. Batrachotoxin is collected from the toxic secretions of frogs from the Dendrobatidae family although it can also be found in some beetles and birds. The golden poison dart frog is around the size of the end of your thumb yet contains enough venom to kill 10 men! For this reason poison dart frogs can afford to be outrageously brightly coloured.
Batrachotoxin is the most powerful naturally occurring neurotoxin with a dose equivalent to just 2 grains of table salt being enough to kill an adult human. It works in tow ways; both as a neurotoxin, causing paralysis and as a cardiotoxin, directly effecting the heart muscles. This makes death almost inevitable and within a matter of minutes.
The element polonium is the ultimate 21st century poison and has been linked to the deaths of Russian dissidents and even Palestinian leader, Yasser Arafat. It is intensely toxic to living things and as such has no known biological role. In its commonest form, Polonium 210 it is reportedly 250,000 times more toxic than hydrogen cyanide. This toxicity is radioactive in nature and caused by the release of alpha particles which damage organic tissue. Alpha particles cannot penetrate the skin but if the polonium is ingested, inhaled or injected it is lethal in the tiniest of doses. In theory a single gram of polonium 210 could kill 10 million people. If the acute effects of radiation poisoning don’t kill you then some form of cancer probably will.
Being a radioactive element, polonium is fortunately both difficult to acquire and handle. This means it is largely reserved for use by governments.
1. Botulinum toxin
Whilst it is impractical to kill using isolated botulinum toxin I’m including it here due to the staggering toxicity of this naturally occurring poison. It is the most poisonous substance known to man. It is estimated that a single teaspoon of botulinum toxin would be sufficient to kill over 1 billion people.
Obviously these figures made the toxin irresistible to weapons developers and it is believed that Sadam era Iraq may have concentrated enough botulinum toxin to wipe out everyone on Earth, 3 times over.
The toxin is produced by the bacterium Clostridium botulinum which can be found worldwide. In its lethal form it is most commonly encountered as botulism occurring when food contaminated with the bacteria is consumed. This form of food poisoning has killed countless people over the ages but is easily avoided by heating the food to over 100 degrees C for a minute. Botulism has been used as a method to murder people on a number of occasions through purposely contaminating food. Botulism can also occur from infected wounds. These days botulism is rarely fatal. In serious cases the neurotoxin causes a wide range of symptoms from paralysis to breakdown of internal organs and death.
Ironically botulinum toxin has found a role in the medical and cosmetic world. It is used to treat excessive sweating, migraine headaches and unsightly wrinkles on lady’s foreheads in the from of Botox. It was estimated that one gram of the toxin was enough to satisfy the worlds annual requirement of Botox.