Lurking inside your faucet is a chemical that seems safe, but can actually be a deadly poison – water. So now you’re probably wondering what the heck ISN’T toxic if a thing that you drink every day can kill you, but if you don’t drink it, that’ll kill you too. We spoke to poison expert Debrorah Blum, and we learned some pretty darn interesting facts about the diverse array of poisons out there. (Reactions opening splash here) “I think of poisons as really cleverly evil compounds, because most chemical compounds, including the ones that build our bodies sustain us in one way or another, and a poisonous compound is a chemical compound that knows how to turn a lock your body and do harm.” Before we get into specifics, it’s good to know exactly how we qualify something as poisonous. Back in the Renaissance, the grandfather of toxicology, Paracelsus, gave us a saying that sums it up, “The dose makes the poison.” “So he made a point about poisons, which was that everything is poisonous or not depending on the dose. If you take a compound like arsenic, in a very tiny dose, it doesn’t kill you. In a very large dose it does. Now, from the 21st century perspective, Paracelsus was right and wrong. Yes, everything notches up according to dose, but there are materials that don’t have a safe therapeutic dose. Lead’s a good example. There is no dose so small that we know in which lead is not dangerous.” To test the toxicity of a substance, scientists use a method called the lethal dose 50%, or LD50. It’s the amount of a substance needed to kill 50 percent of a test population, which is usually rodents. This quantity can then be extrapolated into how much it would take to kill a person. For example, the LD50 of water is 6 liters for someone weighing about 165 pounds. That means if you weigh a buck 65 and guzzle about one and a half gallons of water all at once, you’re toast. So don’t do that. While on the other hand, there are some poisons out there that can kill instantly with a way smaller dose. Cyanide is the perfect example. “We have a lot of experience with poisons killing people because we’ve killed a lot of people over our homicidal history and so cyanide causes an almost instantaneous destruction of the enzymes that process oxygen in your cells. You suffer a very rapid chemical suffocation, it’s damaging the nerves so quickly, you may convulse. So a poison that attacks the central nervous system is going to kill you a lot more quickly.” So a dose of cyanide pretty much certifies you as immediately dead. But there are other poisons that take a long time to finish the job and are nearly undetectable. For example, in 2006, Russian spies poisoned ex-KGB agent Alexander Litvinenko with radioactive polonium-210. “There were assassins from Russia that had put polonium 210 in his tea. It’s tasteless so it’s a great poison. I mean he was desperately starting to be sick within a few hours, but it took him quite a while to die because it’s a radioactive poison, it moves through the bloodstream, deposits in the bones, and it starts just emitting radiation from where it’s lodged so you get this slow cook of the radiation.” Litvinenko, although having symptoms within a couple hours, took around three weeks to die from the poisoning. And toxicologists nearly didn’t even figure
it out. You have to know to look for polonium-210 or else you’ll miss it in an autopsy. It just goes to show you, there really is an incredibly diverse array of poisons out there. In fact, much of the chemists’ beloved periodic table is poisonous. Just how much you ask? Deb, take it away.
“Haha! Man, so much of the periodic table is poisonous. There’s antimony, there’s copper poisoning, you can actually poison yourself with copper. You can poison yourself with… well, nickle’s not so bad, but you can poison yourself with other radioactive elements. You can poison yourself with gold, gold is really toxic. You can poison yourself with silver, but you’ll only turn blue.” That’s right Deb you turn blue, but with enough of it, you can die. But even though there’s poisons everywhere, it’s really not that much of a problem. Like with water, what gives life can also take it away. Some of the world’s most powerful medicines are also poisons at higher doses. So don’t lock yourself away in fear of poisons, step out into the world with an appreciation that chemistry like every science has a dual nature. Check out Deb’s amazing book “The Poisoner’s Handbook”, the link is in the description. And also, don’t forget to subscribe and we’ll see you again soon.