- [Narrator] Our bodies
are such intricate machines that we aren't even close
to fully understanding them. But even absolutely minuscule
amounts of some toxins, like cyanide, can grind that machine
to an indefinite halt. So, grab yourself a hazmat suit and stay behind the protective screen you're watching this on because from snake venom to killer beans, we're about to find out
what the deadliest substance on this planet really is. (exciting music) An apple a day. Have you ever heard the phrase, "An apple a day keeps the doctor away"? Sure you have. But it turns out 30 apples a day will have quite the opposite effect. That's because apple seeds and many other organic foods actually contain traces of cyanide, a chemical compound which
at the right or wrong dose can be extremely deadly. It only takes about 250 milligrams, or a quarter of a paperclip's worth, in a 180-pound human for
it to be fatal. (gulps) Yikes! Cyanide can enter the body as either a gas called hydrogen cyanide or as crystallized salts. Once inside, it stops your
cells from using oxygen. This creates a massive problem, especially for your
heart, kidneys, and brain, as they require the most
oxygen to keep ticking on. And cyanide acts fast. If swallowed, you'd be a
goner in a few minutes; but if inhaled, it could be as little as a few seconds before the lack of oxygen causes your whole body to shut down. Sheesh! Fortunately, you'd have to
gobble about 150 apple seeds to actually consume enough of the stuff to prove fatal. And unless you enjoy hanging
around inside fumigated houses, you won't be in any danger
of inhaling it, either. Even so, I'll be thinking
twice about a second slice of Grandma's apple pie
next time I see her; she says I always inhale the first one. (mellow music)
(graphic whooshes) Metallic mimicry. I always thought the
most dangerous substances would be green glowing liquids bubbling away in a secret lab. But one non-glowing, silvery metal took the lives
of almost a million people in 2019 alone. Jeepers creepers. That metal is lead, and it's found in the
Earth's crust itself. The fatal dose for lead
is relatively high, around 36 grams. But that's not the freaky part. If you're exposed to it, the scary substance can
absorb into your bones and stay there for a whopping 30 years! And once it's inside, it's bad news. You see, the highly toxic metal releases things called radicals into your tissues and bloodstream. These are highly reactive
atoms or molecules that can imitate useful metals
found naturally in the body, like calcium. By tricking your body into
thinking they're calcium ions, they can bypass the protective
barrier around the brain and interfere with its functionality. Whoa! Over time, this can lead to a wide range of intellectual disabilities
and developmental problems that are completely uncurable. Despite its astounding toxicity, though, lead is still used in airplane fuel, some color pigments for paint, and, most disturbingly, children's toys. This is because it softens plastic, making it more flexible and able to return to its original shape if stretched. Kids will chew pretty much anything, so their chances of swallowing
small amounts of lead are much higher than adults'; and to make matters worse, they're more vulnerable
to lead absorption too. Yowzers! That leaves a bad taste in my mouth. Surely there's a better alternative. Let me know what you think down below. (keyboard clicking)
(mellow music) (graphic whooshes) Smaller fish to fry. Because my mom took my
temperature the, err, baby way until I was 17 years old, I'm now terrified of thermometers. That fear worsened when I
discovered that mercury, the liquid metal inside
thermometers, is incredibly toxic. And sadly, as Karen Wetterhahn, a toxic metals specialist, found out, once you're sick, there's no cure. Back in August 1996, Wetterhahn was researching an immensely hazardous
compound called dimethylmercury when a drop of the liquid fell onto her protective latex gloves. Okay, but she was protected, right? Wrong. It turns out dimethylmercury
can pass through latex and was absorbed into her skin without her realizing. Indeed, there were no symptoms
until three months later when she started getting
unexplainable stomach cramps. After five months, she
began losing her speech. Just three weeks after that, she was completely incapacitated. Her life support was
switched off in June 1997, less than a year after her first exposure. And she'd been completely healthy before. Damn. Whilst you are I are
unlikely to have issues with dimethylmercury, a similar toxic compound, methylmercury, is found in seafood, and
it can be life-threatening. You see, methylmercury is
found across our oceans, and is absorbed by plankton. Small fish eat this plankton and absorb the methylmercury from it. Those small fish are eaten by bigger fish, which absorb the compound
from both the fish and the plankton. Even bigger fish come along, and the cycle goes on, each fish accumulating more
methylmercury as it does so. Eventually, those fish find their way onto our dinner plates, ready to pass all that
methylmercury straight to you! Don't get me wrong, in
moderation, fish is healthy; but eat too much and your hands, feet and mouth would start tingling. That's the sign to stop, and happens after eating about 40 milligrams of methylmercury. At doses of around 200
milligrams, though, well, someone's, err, sleeping with the fishes. If you're worried that your intake of quality content isn't high enough, you should hit those Like
and Subscribe buttons! I've got the very best fact videos going, and you're guaranteed to enjoy them. Now, let's back to business. (mellow music)
(graphic whooshes) Ribbituary. One of my favorite stories growing up was the "Princess and the Frog." You know, girl meets
frog, girl kisses frog, frog becomes handsome prince. Luckily for the princess, though, she didn't go smooching
a poison dart frog. That's because their skin
produces batrachotoxin, a tremendously poisonous alkaloid. Alkaloids are naturally
occurring compounds that contain at least one nitrogen atom; many are completely safe, but not batrachotoxin. And the Indigenous people
of Western Colombia, where the poisonous frogs are found, knew this very well. They'd coat blow-darts with the toxin when they went hunting or
needed to protect themselves. But the frogs are too deadly to touch. So to extract the venom, they'd impale a frog on a stick and hold it over a fire until
it literally sweated out. Hmm, sounds like a really
bad barbecue mix-up waiting to happen. How does the toxin actually work though? Well, batrachotoxin binds to
the ends of nerve receptors and causes sodium ions
to flood into the nerves and muscle cells. This irreversibly damages the
cells within muscle fibers, keeping them permanently
contracted and unable to relax, eventually it fully paralyzes them. And certain muscles, like the heart, are incredibly sensitive, likely to fail in under 10 minutes. Yowch! Because the frogs' cells don't rely on the same sodium channels as ours do, the toxin has no effect on them. In our case, however, just 163 micrograms, only slightly heavier
than two grains of salt, is enough for someone to
be writing our obituaries, or ribbituaries. That's 1,000 times deadlier than cyanide. Yep, even though poison dart frogs are only about an inch long, they can churn out enough toxin to end your life seven times over. Times like these I wish I had
as many lives as a cat does. (mellow music)
(graphic whooshes) Di by name. Remember earlier I said how
toxic dimethylmercury was? Well, compared to its evil
cousin, dimethylcadmium, it's nothing. Dimethylcadmium is so volatile, it can explode with the
slightest agitation, which isn't ideal, especially considering
it's found in mines. Seriously, this extraordinarily
reactive compound has a, shall we say, burning desire to simplify
its chemical structure. To do this, it'll steal electrons from almost any other compound
it comes into contact with, generating a violent thermal
reaction as it does so. If you spilt enough dimethylcadmium, it would react so intensely
with oxygen in the air that it would explode, releasing clouds of poisonous
cadmium oxide smoke. So if you survived the initial
blast, it'd be far from over. Breathing in as little as
a few millionths of a gram of this stuff would kickstart
the beginning of the end. It tears through your body, ripping the electrons from your cells and preventing them
from transferring energy throughout your body. With no energy, your organs begin to fail. Even if you're lucky enough to
survive the initial exposure, don't celebrate too soon. Dimethylcadmium is extremely carcinogenic, so the chances of you
getting seriously sick are still very high. Because of this, dimethylcadmium isn't
utilized much by scientists; which doesn't surprise me. Some experts argue that gram for gram, dimethylcadmium is the
most dangerous chemical in the world. Don't get me wrong, working with this is the
scientific equivalent of covering yourself in salmon and trying to outrun a hungry bear. But I might have something even deadlier tucked up my sleeve. (graphic whooshes)
(mellow music) Poison of kings. When someone describes
something as fit for a king, they're normally describing
something exquisite. In the case of arsenic, though, it fits the mold for a
totally different reason. Arsenic is a near-completely
odorless and tasteless liquid, and it's extremely poisonous, which means that throughout history, it's been used for some
pretty nefarious reasons. Back in the 15th and 16th centuries, the Spanish-Italian noble
family, the House of Borgia, were big fans of the substance. By dissolving arsenic crystals into wine or sprinkling it on food, they were able to dispose
of powerful enemies with very little trace. Any sudden mysterious illness
just looked like cholera, a waterborne infection that
was rampant at the time. Both gave victims severe nausea, vomiting, and irresistible urges to go potty. Plus, just 70 milligrams is
enough to dispatch your enemies; that's about a tenth of a teaspoon. And after 48 hours, it's only detectable in the hair and fingernails of the victim. Due to a lack of understanding, though, arsenic was used for all kinds of reasons way back in the day. In Victorian England, companies put it in everything from clothing dyes to wallpaper, resulting in grisly skin
reactions and sickness. Craziest of all, women could even buy
special cosmetic products laced with arsenic that
supposedly removed skin blemishes. All the while, it was simultaneously
being sold as rat poison. It sounds like these people
had more arsenic than sense. (graphic whooshes)
(mellow music) Taipan terror. One of the rules I live by is to stay the heck away from snakes, especially if that snake
has a venom so deadly just one bite's worth
could send 100 people slithering to an early grave. Eek! This is the rare Australian
inland taipan snake. Each bite delivers 45
milligrams of venomous cocktail straight into your veins; and just half a milligram is enough to send you six feet under. Special neurotoxins in the venom block the nerves in your body from giving and receiving signals, severely damaging your
ability to do anything, from walking to remembering your own name. Even worse, a different kind
of toxin called myotoxins kill your muscle cells, causing total paralysis. Add in an enzyme called hyaluronidase, which increases the
poison's absorption rate, and you've got a recipe for disaster. The most gruesome ingredient
of all, though, is hemotoxin; just a single drop can
turn a vial of blood into a thick blob of jelly! Ew! Despite all this, amazingly there are no
reports of human death by inland taipan snakebite. The antivenom is so effective
at containing the rapid spread that if it's administered
within 45 minutes, you'll probably be okay; if not, well, I'm packing your Jell-O-fied body between two slices of bread before it's sent off to the
peanut-butter palace in the sky. (mellow music)
(graphic whooshes) Strych out. If you're ever in the jungles
of India or Southeast Asia and you start to feel a bit peckish, choose your snacks wisely. Whilst the small orange berries
of the Strychnos nux-vomica might look oh-so-sweet, their seeds contain high levels of the toxic alkaloid strychnine. If you consumed as little as 80 milligrams of strychnine, which is a little more
than a grain of wheat, you'd suffer wildly painful symptoms. After only 10 minutes, all your muscles would start convulsing, growing more and more violent
as the seconds passed. After two or three entire hours of this excruciating experience, the muscles that control your
breathing would stop working and end your suffering for good. Sounds horrible, right? Well, appallingly, the same Victorian doctors that recommended cyanide as a beauty aid thought tiny doses of strychnine
could be beneficial too. You could buy strychnine
pills for treating paralysis, to help you study harder, and even to assist in some, uh, late night mattress wrestling. To avoid bumping off all their patients, doctors administered it in doses as low as one 1/24th of a grain of wheat, and they sold chocolate coated pills too. What's next? Explosives covered in bubble wrap?! (graphic whooshes)
(mellow music) Wheezy weapons. Some substances are so deadly that they're not just
banned from public use, they're banned full stop. Sarin is just such a substance. Originally developed as a
man-made pesticide in 1938, the odorless, colorless liquid became internationally outlawed in 1997 after a string of horrifying
attacks on civilians. Even so, sarin has been used across Syria as recently as 2018. It's an extremely potent nerve agent that evaporates into a toxic gas at just 71.6 degrees Fahrenheit. If you breathe it in, it'll cause a myriad of awful symptoms, from headaches to confusion,
to weakness and diarrhea. And at higher doses, it quickly blocks your nerve endings, preventing your muscles
from being able to relax; so you'll not only feel terrible, but every part of you will also
be tensing and cramping up. Eventually, anyone unfortunate enough to encounter a lethal dose of sarin will fall into a coma and suffocate. Nasty stuff. So just how potent is it? Well, if you mixed a mere
sixteenth of a teaspoon of sarin with 264 gallons of water, one swig would be enough
to have you pushing daisies after just two minutes! Geez! That's a whopping 26 times
more deadly than cyanide! All right, but say you got
stuck in a cloud of the stuff, couldn't you just hold your breath? Nope, there's really no point. The deadly gas will absorb directly into your eyes and
skin regardless. (shudders) Really puts a different
spin on the phrase, "I had a skinful," doesn't it? (mellow music)
(graphic whooshes) Puff of smoke. We all know smoking cigarettes
is bad for your health. But for all the dangerous
manmade chemicals in cigarettes, one of the naturally occurring substances could cause you the most harm. Nicotine, the addictive chemical
of the tobacco plant, is extremely deadly in its purest form. Exactly how much you'd
have to consume, however, is still under debate. Some estimates put it
as low as 50 milligrams, but it's more realistic to
say around 500 milligrams or the weight of half a US dollar bill. Now, it's unlikely you're
going to overdose on nicotine from smoking cigarettes. Your body only absorbs about
1/10th of the nicotine in one, which is about a milligram. But many e-cigarettes
pose a much bigger risk. Some nicotine liquids
are sold at strengths of up to 36 milligrams per milliliter. Even at this strength, you'd have to vape an
absolute butt-ton to overdose. But that's not the risk. If you touch a high strength e-liquid, the nicotine can be absorbed
straight through your skin and make its way to your bran; once inside, it causes a blockade between your brain and the nerves controlling your muscles, and can lead to vomiting, seizures, and even death. Accidentally getting some
on your hand will be fine, but I'd advise against getting in a bath full of the stuff; you'd go out like a puff of smoke! (graphic whooshes)
(mellow music) Something in the water. Did you ever have a nickname in school? Mine was milk-putting. I'm white like milk, and the other kids kept pudding
me inside their lockers. Ah, the good old days. Some toxins, like anatoxin-a, have badass nicknames, too, like Very Fast Death Factor. Whatever, I still think mine's cooler. Anatoxin-a's nickname makes
a lot of sense though. It's the silent killer responsible for wiping out herds of cows across North America since the 1980s. After drinking contaminated water, cattle have been found lying
stone cold just minutes later. Yikes. That is fast. It's produced by cyanobacteria, a type of bacteria that lives in freshwater bodies around the world; in other words, where cows drink from. Anatoxin-a is so deadly
because once it's inside you, it binds to things called
nicotinic acetylcholine receptors. These receptors are responsible for controlling your muscles. Normally they open and close depending on what you're doing. But after anatoxin-a has
attached itself to them, it forces them to stay open
and overstimulates your muscles to the point of exhaustion and paralysis. You might lose coordination,
start twitching, convulse, and eventually be unable to breathe. Nice. The lethal dose is still somewhat shrouded in mystery though. When injected in mice,
it's overwhelmingly low, roughly 1/500,000th of a teaspoon. But symptoms don't even
start showing in humans until around 1/16th of a teaspoon. Okay, that's still not much at all. But don't panic. That next glass of water
won't leave you face down in the sink. Our drinking water goes through
a lot of different processes to make sure it's free
of anything dangerous. Just try and avoid drinking from any dodgy looking
ponds or streams, okay? Mean bean. Here's one of my favorite
rhymes: (clears throat) Beans, beans, the musical fruit. The more you eat, the more you toot. Pure poetry. Just make sure that you're
not eating the beans of a castor plant, because they contain a
deadly toxin called ricin. If you squeeze the oil from castor beans, you're left with a mushy pulp from which the toxin can be extracted. But it's also released
just from chewing on them. And only 80 milligrams, or about 8 beans, is enough to make you a has-bean. But the amount can be as little
as 22 millionths of a gram if injected directly
into your bloodstream. You see, ricin is a
ribosome-inactivating protein, or RIP. Yeah, appropriate name, right? Basically, it wrecks your ribosomes, which produce protein for your cells. Without protein, your cells,
and you, cease to function. Indeed, you'll be resting in
peace within about 72 hours of ingesting the RIP. And they'll be a bad 72 hours. First, you'll feel a bit sick. This will get worse, until
you're vomiting and pooping all over the place, resulting in severe dehydration. Within a couple of days, you might start having seizures too. Finally, your organs
will give out completely. Damn! Indeed, it's been used
to devastating effect in more recent times too. Georgi Markov, a Bulgarian
writer and defector, was, err, removed by the Bulgarian
secret service in 1978 when a suspected ricin
pellet was shot into his leg from a modified umbrella. Man, Queen got it wrong when they sang "Killer Queen." (graphic whooshes)
(mellow music) Fishy business. I love sushi. But it blows my mind how fish
and rice can be so expensive. That said, it's not worth cheaping out. Badly prepared seafood is the
leading cause of intoxication from tetrodotoxin, a poison you really
don't want to mess with. It's found in a wide range of seafood, but most famously in pufferfish. And as little as one to two milligrams, the weight of half a mosquito, is enough for an average
human to become worm food. Ew! That's because tetrodotoxin attacks the channels between nerves and prevents them from passing messages, rendering the tissues within your muscles practically useless. Symptoms start showing in just 10 minutes. The first sign is a tingling
sensation in the lips, which rapidly spreads
to the arms and legs. This doesn't last long. Soon, the victim becomes
totally paralyzed, their breathing labored and difficult. In most cases, the unfortunate soul
remains totally conscious throughout the whole
horrific ordeal, until, well, I think we all know how this ends. Worst of all, there's no antidote. The best treatment is
administering breathing support and offering your hopes and prayers. Jeepers. I feel like I need breathing
support just hearing about it. (graphic whooshes)
(mellow music) Canned if you do. At the beginning of the 20th century, canned food production was becoming a nearly
billion-dollar industry. But little did these
early tin-novators know, their products were a breeding ground for one of the world's deadliest toxins, the bacterium Clostridium botulinum. Unlike most organisms, it thrives in places devoid of oxygen; so a sealed can of food
provides the perfect conditions. Once inside, it creates spores, which are minuscule reproductive units capable of multiplying incredibly quickly. So the deadly bacterium
just grows and grows. And the lethal dose is
incomprehensibly minuscule, only 2 nanograms, that's two-billionths of a gram, will have an unlucky
eater kicking the bucket, or indeed the can. How insane is that? That's the same size as
a single grain of rice cut into a staggering 12.5
million little pieces! Ingesting this bacterium causes botulism; and believe me, you don't
wanna get this sucker. Starting from your face down, all your muscles will go weak before becoming completely paralyzed. At this point, unless you get speedy help, it'll all be over. Luckily, because of better
food safety standards, cases nowadays are very rare. I'd still avoid these though. Botulism would be the
least of your worries. (graphic whooshes)
(mellow music) Radioactive risk. Remember back at the
beginning of this video when I told you about cyanide? If you thought that sounded dangerous, wait until you hear about polonium-210. It's a rare, highly radioactive metal used in the production of
nuclear bombs, so yeah, it's pretty deadly. By weight alone, it's around 250,000 times as
toxic as hydrogen cyanide. The lethal dose can be as
little as 0.089 micrograms. That's like taking a
single grain of table salt and breaking it into 674 pieces. Indeed, just one gram is enough to make 50 million people incredibly sick, and another 50 million into worm food. That's the population of
New York six times over all gone from one tiny gram. Holy cannoli, that's dangerous! Thankfully, getting a whole
gram is near impossible. Polonium-210 exists in such
minute amounts in nature that it's often undetectable. What makes it so unbelievably deadly then? Well, polonium-210 atoms
have an excess of energy inside their nuclei. Unable to contain this energy, they fire out heavy, highly
energized alpha particles. These have protons and
neutrons, but no electrons; and that's bad news. The particles are too chunky
to get through your skin, but they can get inside your body via contaminated air, food, or water; and once they do, they'll tear through you and
steal your cells' electrons as they do so. This seriously damages your DNA and can cause cell mutations, leading to cancer, organ
failure or even apoptosis, where your cells just give up the ghost. Kaput. That was the sad fate
of Alexander Litvinenko, a Russian defector and currently the only known case of deliberate polonium-210 poisoning. After Russian agents spiked
his tea with 10 micrograms or 200 times the lethal
dose for ingestion, Litvinenko became horribly sick. This is the last known photo of him, taken less than three weeks
after he was poisoned. Just days later, he died. (sighs) I wouldn't wish that fate on anybody, not even my channel's competitors. (upbeat music) Phew! On that chirpy note,
that's all we got time for. Which of those killer chemicals would you least like to
come in contact with? Let me know in the comments down below. And thanks for watching. (upbeat music continues)
