I am amazed when I hear about stuff that can kill you in incredibly tiny amounts:
One milligram of toxin from the golden poison frog (Phyllobates terribilis) can kill 10-20 people. A teaspoon can hold about 5,000 milligrams of water.
Karen Elizabeth Wetterhahn died from mercury poisoning after accidentally getting a few drops of dimethylmercury on her rubber gloves in the lab. It turns out it can permeate latex gloves. She died about a year after the exposure accident.
A dose of the military nerve agent Novachock 1/30 the size of a raindrop is fatal. If you breath air that has 2 mg. per cubic meter it will kill you in two minutes.
I do not understand the mechanisms for how any of these things kill you but I am astonished at the tiny amounts needed.
Drowning can be triggered by getting even a teaspoonful of water in the lungs and the way our bodies react means there may be nothing we can do to stop it.
That’s the first line of the article but the rest of the article seems to describe a submersal scenario. It doesn’t really explain how you can drown from a teaspoon of water.
Novichok is a acetylcholinesterase inhibitor, much like VX, Soman, Tabun, etc… Think of it as Malathion for people. It inhibits acetylcholinesterase, which is an enzyme involved in breaking down acetylcholine (a ubiquitous neurotransmitter). Inhibiting the breakdown of acetylcholine means that you end up with too much of it, and all sorts of weird stuff starts happening in your nervous system, including disruption of the signaling between your nervous system and muscles. This includes your heart and lungs, as well as everything else. In effect, you suffocate because the signals to your diaphragm get scrambled.
As you might imagine, something that messes up your neurotransmitters probably doesn’t need to involve a lot of the actual substance.
In other words, if you take a normal 60-kilogram adult human, it takes only perhaps 100 nanograms of botulinum toxin to kill him. The average human cell is one nanogram.
Each of these substances (batrachotoxin from P. terribilis, dimethylmercury in the Karen Wetterhahn lab poisoning, and for Novichok some kind of organophosphorus-based nerve agent) are all neurotoxins, and while each of them have very different functional mechanisms they are readily distributed around the nervous system with only a tiny quantity required to disrupt individual nerve channels and cause progressive systemic failure. Methylmercury is especially persistent in the body and basically cannot be broken down or purged without aggressive chelation therapy, and even then only if the treatment is performed within a few hours of exposure. I see bump has described the mechanism of VX-type nerve agents, and batrachotoxin are an alkaloid toxin that interferes with modulation of sodium channels.
While you could technically “drown” with just a few teaspoons of water sufficient to obstruct the airway (and inhaling a small amount of water can result in pulmonary edema which can cause delayed issues, which is why anyone who has been rescued from drowning should be taken to emergency medical facility for examination), most people will instinctively self-correct (e.g. violently cough) and expel the water. One of the dangers of waterboard “interrogation” (i.e. torture) is that the subject in an inverted position can end up accumulating water in the sinuses that gets repeatedly expelled into the airway, obstructing airflow. This was also a concern early in the space program for astronauts in space drinking fluids but with a little practice the peristaltic action of the esophagus (e.g. aggressively swallowing) will overcome any tendency to inhale any free floating droplets.
The newest iterations of fentanyl are getting right up there. Gets to be a problem when it’s used to cut heroin and the person doctoring it up doesn’t realize they have the high caliber version of fentanyl and kills some people. Or dies from absorbing it while handling the stuff. I don’t understand why it makes sense to continually approve drugs so unbelievably concentrated it becomes nearly impossible to concoct a dose that WON’T kill you.
The lethality of mercury always amazes me, given the frequency w/ which I and every other kid who could get some messed around with it back in the 60s.
Mercury’s lethality depends on which salt it is. Some are relatively inert, and others, like the one referenced earlier, are fatal on any direct exposure.
Peanut allergies are nothing to mess around with, either. Interestingly, this does not seem to exist in cultures where peanuts are a staple food.
