There are somewhere in the region of 118 elements that are known of. The reason for being vague is that some are thought to exist but have never been observed. Of these 98 occur naturally. Very few of these elements are completely harmless and most present some risk in sufficient doses.
There are no hard,fast rules as to which elements are likely to prove most dangerous but we can divide the risks into three general categories. Those that are toxic, radioactive or highly reactive. Some even fit all three categories.
The thirty or so heaviest elements are all radioactive to some degree. Generally, the heavier the more radioactive. Listing those wouldn’t make for a very interesting top 10 deadliest elements so I’ve skipped a bunch of these and gone for the most exciting dangerous chemical elements.
10. Chromium (Cr)
Mention chromium and most people are thinking shiny car parts. It is also one of the elements that is essential to most higher organisms. But chromium has a dark side.
In one of its forms (hexavalent) chromium becomes a genotoxic carcinogen – that is something that can interfere with your DNA, increasing your chances of developing cancer.
Alarmingly there seem to be plenty of examples of industrial pollution involving hexavalent chromium, even in “developed” countries. Dangerous levels have been recorded within the past 5 years in both Australia and the USA.
9. Hydrogen (H)
The smallest and most abundant of all the elements, Hydrogen might not seem like the most obvious choice. However, if nothing else, hydrogen is incredibly flammable. Perhaps the most infamous case of hydrogen combustion was the Hindenburg airship disaster after which it didn’t seem like such a good idea to fly around attached to a massive tank full of highly flammable gas.
An added danger of hydrogen fires is that the flames are almost invisible. This means you could be incinerated before you even saw the fire.
The main reason I’ve included hydrogen on this list is that it is the key ingredient to all things acidic. The hydrogen ion or proton (H+) is what gives acids their acidic properties, some of which are considered extremely harmful. Chief amongst these are acids’ high affinity for water – upon contact with organic matter (e.g. human skin) intense dehydration will occur which is pretty much equivalent to burning. Sulfuric acid, for example, can cause deep burns within seconds. If you think that sounds bad the superacid, fluoroantimonic acid, is over one billion times stronger…
8. Lead (Pb)
Lead used to be used for everything; paint, eating utensils, toys and water pipes just for starters. Then someone noticed it was highly toxic. Whilst it might not be the most toxic element it is probably the most likely of these nasties you’ll come across
In high enough doses lead can be lethal. Symptoms include vomiting, staggering, weakness, seizures, coma and death. But this is rare, it is long term exposure that gets most people. Whilst still serious in adults, lead poisoning is particularly destructive in children. This is because it stunts the developing nervous system leading to irreversible damage. In short lead can permanently reduce your IQ.
7. Beryllium (Be)
Despite its pretty sounding name and the fact beryllium is made in stars it has some rather nasty properties. The dust from beryllium is so bad for you when inhaled that they even named a disease after it; berylliosis. This incurable condition causes lesions in the lungs similar to those found in tuberculosis. The symptoms are in fact often confused with TB and the long term effects may result in lung cancer.
Beryllium is a category 1 carcinogen, it is also very useful in a number of industries.
6. Fluorine (F)
Fluorine is a generally unpleasant substance. The unappealing pale yellow gas is corrosive, highly poisonous and will try to react with almost anything – often explosively. It is chlorine’s more unstable big brother and as we know chlorine makes bleach and mustard gas, amongst other things.
Just 25 parts per million (0.000025%) concentration of fluorine is potentially lethal. It acts by attacking the lungs, airways and eyes, effectively blinding and suffocating the victim. Think mustard gas, but worse and that’s fluorine.
On the positive side, fluorine is great for your teeth!
5. Mercury (Hg)
The poisonous qualities of mercury have long been known about thanks to the self-sacrifice made by early dentists and hatters – apparently the phrase “mad as a hatter” comes from the fact that mercury was used in hat making resulting in high levels of dementia.
One of the things that makes mercury dangerous is it can be absorbed through the skin. In addition mercury also evaporates quickly making inhalation a real danger.
Another worrying feature of mercury is its ability to build up in the food chain, particularly seafood. This is because evaporated mercury eventually ends up in the sea or lakes.
The most noticeable effects of mercury poisoning are neurological. All the senses may be effected, along with coordination and muscle strength. Memory is also likely to be affected.
Sufficient doses of mercury are likely to be fatal as Emperor Qin Shi Huang of China found out when he took several pills intended to give him eternal life!
4 Arsenic (As)
The poison of choice for the Victorian lady, arsenic is amongst the classic poisons. As well as using it to kill each other they decorated their houses with it using it in both wallpaper and paints. It is believed that accidental poisoning from such sources sent King George III of Britain bonkers and ultimately lead to the death of Napoleon Bonaparte.
As with lead, arsenic poisoning can be a sneaker, building up over time causing a range of symptoms. There is nothing sneaky about a high dose though; the main consequence is intense gastric distress in which everything goes wrong with your gut – vomiting, diarrhea and bleeding, and plenty of pain. Death often follows within hours.
3. Caesium (Cs)
The super-reactive metal caesium (or cesium) needs very little encouragement to spontaneously explode. In fact just the presence of thin air is enough to make caesium burst into flames. If your natural reaction would be to throw water on this, that might not be such a good idea – contact with water makes it explode!
For this reason caesium must be stored in a vacuum, and only in small quantities.
In addition to these explosive properties cesium is also quite toxic and mildly radioactive.
2. Polonium (Po)
Whilst polonium might not be the deadliest element per se, it is probably one of the most effective poisons used by man. Weight for weight polonium-210 is 250,000 times more toxic than cyanide. This toxicity is radioactive in nature and caused by the release of alpha particles which damage organic tissue.
Now, the good news is that alpha particles cannot penetrate the skin. The bad news is that if ingested, one gram of polonium 210 would be sufficient to kill 10 million people.
Fortunately (or not), the difficulties in obtaining and handling polonium mean its use is largely the reserve of governments.
1. Plutonium (Pu)
All the elements with an atomic number of 84 and above are radioactive. The simplest explanation for this is they are too big and unstable and breakdown giving off lethal radioactive particles as they do.
The biggest and baddest of all the naturally occurring elements is plutonium with an atomic number of 94. Unlike other naturally occurring radionuclides Pu gives off alpha, beta and gamma radiation. As well as being highly radioactive this element is also toxic like other heavy metals are.
Inhalation is the most harmful route for plutonium exposure and one estimate suggests 500g of plutonium dust released into the air would be sufficient to kill nearly 2 million people. If this is the case it is slightly alarming that there are several tons of the stuff in the biospheres thanks to weapons testing in the 1950s and 60s!
In addition to these toxic qualities plutonium is also the material of choice for nuclear weapons. Consider the one kilogram of pure plutonium pictured – this contains sufficient energy to power a major city for several hours. It is also sufficient to make a 10 kiloton explosion, i.e. the same as 10,000 tons of conventional explosives. This is about half the size of the Hiroshima bomb.
Mostafa Eehab Khalil says
Hey guys, so I would like to end the commotion in the comments because of Fluoride. Fluoride is dangerous as a lone inorganic chemical, let’s just say it like that. In fact it is quite notorious. However, it is used in toothpastes. If one were to pop into their bathroom and look at their toothpaste’s ingredients, you would see something called “Active Ingredient” with a chemical next to it called Sodium Monofluorophosphate, I think. If one were to search it up, Sodium Monofluorophosphate is very much harmless and can serve two main purposes: firstly in toothpaste and secondly in some certain medical applications. What I want to say is that adding some other element(s) with fluoride can greatly increase or (in our case) decrease its danger to the point where it is virtually non-existent. In the end, we conclude that there is so much more to a subject than what is seen at first glance. There is so much to learn, and instead of wasting your time by calling each other out for something that both sides of the argument don’t understand, look it up on the different websites out there.
I hope this solves this problem for the time being.
rather not tell says
why didn’t Darmstadtium make it?
rather not tell says
why didn’t Ununquadium make it?
DANIEL ROSENTHAL says
If more than a certain amount of Plutonium is in one place at one time, it can “go critical” and release lethal amounts of radiation as it undergoes a meltdown. If it is compressed to a high density it will produce an enormous explosion–enough to destroy a medium sized city; this is how a nuclear bomb works. Case in point: Nagasaki.
Thallium, the most poisonous stable element which is fatal at 15 mg, which also has a long history of use as a murder weapon and has been called “The Poisoner’s Poison” for its difficulty to detect. I understand that you didn’t want to flood the list with radioactive elements, and you didn’t include chlorine because there was fluorine, but Thallium can’t really be replaced by any other elements on this list.
John P Marmaro says
All significantly radioactive elements might be on this list By the bye, ordinary cesium is not mildly radioactive, as it is comprised of only one isotope, Cs-133, which is stable. There is a small amount of radioactive Cesium 137 throughout the environment due to nuclear bomb tests and accidents, but ordinary (mineral-derived) cesium is unlikely to have any of that. While ordinary cesium is NOT “mildly radioactive”, its lighter congeners, rubidium and potassium, ARE. (Each has a naturally occurring primordial radioisotope; much of the heat within the earth is due to Potassium 40; most of the radioactivity of the human body is due to potassium) I agree with Mr Brower: radon deserves special mention. It is one of the most insidious of the toxic elements, as, though its half-life is a tad less than four days,.. because it is a gas, it is breathed in and decays in the lungs, where its daughter elements, all solids and all highly radioactive, collect and cause great damage. And it is continually produced by the uranium and thorium in rocks and soils. You’d think four days isn’t much time for the gas to seep up into houses and the atmosphere, but as Rn is relatively inert chemically, there’s little to prevent that seepage,
Fluorine gas if of course one of the most aggressively dangerous substances on (or off) earth, but one is not likely to encounter it in everyday life. But fluoride ion is another story. It is VERY toxic– sodium fluoride (yep, the ingredient in toothpaste) is used as insect and rat poison… a gram (one thirtieth of an ounce) can be lethal. So when the instructions for using fluoride toothpaste tell you not to swallow it… they mean it,
I don’t believe that sodium fluoride has been used as a poison, I think you are referring to sodium fluoroacetate. Sodium fluoride is toxic, but not that toxic, and there isn’t much in toothpaste. I once swallowed a big glob of toothpaste (when I was a kid) and I was fine.
Luis Quijada says
yeah, but when we used it everyday on toothpaste and water of course it will lead to problem in the end.
Chris Simons says
Based on what evidence? Let me guess, you saw it on YouTube… AFAIK life expectancy and public health has been increasing for the last 150 years, why look for conspiracies?! This kind of uninformed opinion is almost as bad as the antivax BS…
Paul Brower says
1. Radon, a radioactive gas.
2. Phosphorus, especially white phosphorus. It literally burns flesh.
3. Cadmium. Even more toxic than mercury.
4. Uranium. Both radioactive and poisonous.
5. Oxygen. We need it, but liquid oxygen impregnates many things and makes them incredibly flammable.
6. Chlorine, Highly toxic, corrosive gas.
7. Nitrogen. Component of some of the world’s most dangerous explosives. Will suffocate you and leave no marks,
I’m working toward the radioactive elemental sodium metal. Water/air reactive (see: fire) and hard to treat without vitrification. The glassification keeps it immobile but realistically? The reactive characteristic is removed by the loosely tethering it to the high temperature (resistance in ohms) and the metal is stable within the glass.
Astatine is most dangerous.
That’s 2 letters not 3
H Paul Honsinger says
I was surprised that Actinium wasn’t on the list, given that we can’t even put together a more than a few micro grams of the stuff without it spontaneously exploding. It’s so nasty that no one can even tell you for sure what it looks like because no one has ever been able to make enough to be visible without it self destructing.
Matthew B says
I’m just looking for a dangerous material for my book. Summary of part of the book: He finds ______ (Material im looking for) It explodes, he wakes up and a few days later he discovers he has superhuman abilities.
Go for francium, it’s literally never been mixed with water (and will cause trouble if someone did)
What kind of trouble
Mostafa Eehab Khalil says
Critical trouble.. I believe. Francium is notorious for its radioactivity. And what is every radioactive material known for? Instability. Under the right conditions, it can go supercritical (the stage where it is on the brink of going boom). Mixing it with water wouldn’t make it any better. The mass of Francium that is mixed with water would explode and flood the room (or wherever the place) with potentially lethal doses of radiation.
Stop calling each other numpty just because someone made a mistake (although the actual element is fluorine and fluoride is the molecule composed OF fluorine) so that was not very nice. People should not call each other names over mistakes. Make a little correcting would do WITHOUT the word “numpty”?
There is one error that I spotted; “all elements 84 and above are radioactive”. There are so much more radioactive elements like thallium and uranium. They kill people in an instant. Other than that, this is an awesome article and I never knew that lead can lower the IQ. I thought it was just poisonous and can cause cancer. Nice job on this! Now I want to know how number 83 on the periodic table, bismuth, is able to cure and what famous medicines use bismuth. Thank you for presenting such a cool article.
That is not an error; It does not mean that all radioactive elements are above 83, it means that elements 84-118 are radioactive, which is correct. BTW thallium is NOT radioactive, and uranium is above 84. Also, in case you were wondering, Bismuth is slightly radioactive too (half-life is longer than the age of the universe, but it still counts). The only unstable elements under 83 are technetium (43) and promethium (61). Cesium is technically not radioactive because it has a stable isotope.
Daniel Blake Shoemaker says
What about Thallium, White Phosphorous, etc. 150 mg of white phosphorous would kill you min and 500 mg of thallium (Thallium sulfate) would cause very painful and slow death by destroying the entire nervous system. It a cancerous accumulative heavy metal that interferes with ATP and causes fluid retention causing cell brain white matter death, etc. Why don’t you add Thallium salts??
Plutonium doesn’t occur naturally…
Yes but also why does it say “500g of plutonium can kill 2 million people”? That is not true! Only half a gram kills 2 million people!
Mostafa Eehab Khalil says
Actually, the article was right… If one were to look it up on the wiki, 500g of plutonium would kill 2 million people. I am not sure if you mixed it up with some other dangerous element. The article states that if 500g of plutonium was inhaled and not used in a bomb, so maybe check again?
Devid Kobozev says
What about Radium or Francium?
Caesium is basically just a more reactive version of francium. Also I didn’t want the list to just include radioactive elements – thought it would be more interesting to include other forms of toxins.
FLUORIDE is the negative ion of FLUORINE and FLUORIDE is used in toothpaste in very small, so YOU’RE the numpty. FLUORIDE IS NOT FLUORINE. You can’t jut change the last three letters whenever you want.
you change FLORINE to FLORIDE when it reacts with different elements…
I KNOW THAT AND IM JUST A KID
*sigh*… no one knows high school chemistry. Yes, jake is correct. fluorine is quite reactive because it needs one more electron to fill its shell. Fluoride is F-, which means it HAS gained an electron and filled its shell. Of course, it has a charge so it is still not so stable, but it is less reactive than un-ionized fluorine. You don’t “change” fluorine to fluoride, it changes by gaining an electron.
Mostafa Eehab Khalil says
Finally… someone put an end to this madness. I agree with what you said. Also, be calm and stop calling each other out. Everyone makes mistakes.
Elijah Kelley says
Why isnt chlorine in this
Because, as it says in the article chlorine is basically fluorine-lite. I could have listed both but I decided fluorine did the same but more.
Admittedly it hasn’t been weaponized to the same degree as chlorine, but that is probably because it is too unstable.
The “positive side” of fluorine statement was in sarcasm I hope.
fluorine is in toothpaste you numpty
EyeOfHorus 1493 says
FLUORIDE is in toothpaste. YOU’RE the numpty.
Well, fluorine is in fluoride, so technically fluorine IS in toothpaste…
Fluorine is very healthy in small quantities if you aren’t an idiot conspiracy theorist who doesn’t know how to examine scientific evidence.
Random person says
Honestly it is not suppose to be in toothpaste period no matter what health effects are in Fluorine the point is that it is not suppose to be there and honestly you do not know WHAT the **** it is doing to your insides you can only estimate and guess. You do not normally consume it.
It’s there because it cleans your teeth and that’s the whole point of toothpaste?
are you dead?
Random person says
If you have to use it in small amounts for you to not get sick then what is the point of using it because it must honestly be really bad.
Adarsh Tiwari says
But only in it’s compound
A chemist who worked on chemical weapons for the US Military during WW II, was asked to go to Germany to run I. G. Farben, the infamous chemical company that made Zycon B that killed the millions of people in Concentration camps run by the Nazi’s. He found in their records that they experimented with Flourides. They found that ingestion of minute amounts made the populous docile and more willing to cooperate. The Nazi invaders did use flourides, put in the drinking water and found that there was a marked drop in resistance.
Conspiracist bullshit! Yep, we’re all being fed liquid prozac by our Illuminati infiltrated governments.
Anybody who takes this shit seriously is probably beyond help, but you can do your own research – just choose your ‘experts’ carefully…
why do people just throw away info that goes against what they believe in
The elements you use concerning natural radiation is actually known as just very very weak harmless emitters that can not mutate a fruit fly . Even if refined down to mass they are still just weak emitter but toxic to life yes not that humans come in contact with them refined . Now concerning man made radiation rule of thumb they are by comparison millions of times more energetic and dangerous than natural hence nuclear waste sites terrorist laws bal bla bla .
A gram of natural refined emitters is about 1/10,000,000 of a curie and a curie is 37,000,000,000 atoms so a gram of natural emitter puts out around 160,000 harmless atoms but man made puts out 88 curies per gram or 88 times 37 billion vicious atoms pulsing right through your body and able to be picked up on a Geiger counter every second , big difference yea .
When it comes to people being exposed to natural consider 10 prescription pills taken at once is considered a lethal dose for 50 percent of the population and consider 300,000 die each year of properly and appropriately prescribed prescription drugs yet no one died from the material you used .
Concerning man made isotopes a single one will give you cancer in 20 to 50 years but some of up to 1800 auto immune diseases can and do show up before the cancer in study’s on animals because of that one man made atom . Consider Fukushima lost millions of pounds not a gram and is still blasting an made radiation up into the jet streams and ocean and will have to babysit Fukushima 3 meltdowns for at ;least 3000 years if they don,t run out of homeless first and lose the site .
Why caesium? Why not frankium that is more dangerous when in contact with water
I read otherwise, i.e. francium is not as reactive as caesium: http://chemistry.stackexchange.com/questions/9051/why-do-the-trends-in-reactivity-not-apply-for-francium. Also francium is so rare (only 30g exists naturally at any given time) that I figured it posed less of a risk than caesium…
Mostafa Eehab Khalil says
I believe that francium was synthesized by bombarding some other slightly more stable atom.
Can’t believe thallium didn’t make this list.