Last semester I had a series of lectures for my module in Toxicology. It’s one of my favourite modules I’ve taken here. Since then, however, I’ve been asked on a few occasions what the worst poison on Earth is.
And that’s a pretty difficult question.
The deadliest poison I’m aware of is botulinum toxin, otherwise referred to BTx or Botox. The BTx we use for cosmetic procedures is lethal if you inhale around 1.2 micrograms. For reference, a single drop of water weighs around 50,000 micrograms. There’s also “Type H” BTx, which is 600 times more potent. Just 4 milligrams of this stuff could kill every single human being, assuming you share it out perfectly.[pullquote]The recent Salisbury poisoning (which may lead to World War III) was caused by an organophosphate called A234 that can cause poisoning on contact[/pullquote]
BTx is hard to use. though. It needs to be made by the right species and strain of bacteria, purified, refrigerated in an appropriate buffer, and it doesn’t spread in the air well. In terms of worst poison for easily killing people, then look no further than organophosphates. These work by effectively blocking up the clean-up processes in the brain, causing your nerve cells to overload. The recent Salisbury poisoning (which may lead to World War III) was caused by an organophosphate called A234 that can cause poisoning on contact. There’s also organophosphates in your mattress, but they’re not deadly. At least, not with short-term exposure.
But what about long-term exposure? Things get a bit more nebulous there, where the lines between toxin and therapeutic agent begin to blur. Alcohol killed over 7,000 people in the UK in 2016, but drinking in moderation has been linked to reduced chances of heart disease.
However, there is a long-term poison that has killed lots of people with no therapeutic benefits whatsoever – asbestos. Responsible for multiple different cancers (and that weirdly recurring copypasta about “if you or a family member have been diagnosed with mesothelioma”), asbestos kills cells that try to engulf it, causing them to release chemicals that stimulate inflammation and cell growth. Over time, this leads to cancer formation and lung fibrosis, both of which highly unpleasant. Asbestos is responsible for the deaths over 150,000 people in the USA alone.[pullquote]Sulphur mustard or “mustard gas” creates blisters on exposed skin that are extremely painful if even lightly touched[/pullquote]
Then again, the worst poison could just be the one with the nastiest effects (reader discretion is advised for the following paragraph). Tetanus toxin or tetanospasmin is a strong contender, causing you to clench your muscles repeatedly, which can result in permanent muscle damage, broken bones, and even a severed spinal cord.
Alternatively you could go for ergotamine, which also causes muscle clenching but to a much lesser extent; unless of course you are pregnant, where the uterus will contract with devastating effects upon the unborn fœtus. Sulphur mustard or “mustard gas” creates blisters on exposed skin that are extremely painful if even lightly touched, then follows up with various forms of skin cancer later in life.
Finally (and on a much lighter note), the “worst” poison might be the one that requires the largest necessary amount to kill you – a poison that is really bad at its job of being a poison. In which case, I’m happy to report that the world’s worst poison is water. You “only” need around 7l (about 12.5 pints) to kill you. And even that can be counteracted by adding some salts and sugars to it, which is why sports drinks are often encouraged when exercising. Drink up!