From the Vault: Heavy Water

Joe McCormick. And today I wanted to start off by talking about something that may have come up in the past on the show of CORP. I don't quite remember, but I don't think we've ever gone into great detail on it. So there is this popular chemistry prank that that goes some thing like this. You you approach somebody with a petition or a public service announcement. Uh. And if I could do the Donald pleasants like Spirit of Dark and Lonely Water Voice, I would do this. But

just imagine it. Can you imagine I'm I'm Donald Coleasant saying this to you. What if I told you there was a household chemical present in more than ercent of homes in America, which is used as an an ingredient in everything from packaged foods, to cleaning products to children's medicine. And yet this chemical has been proven to cause severe burns to the skin and mouth, can be lethal if it's inhaled, and is the primary constituent in acid rain.

According to historical sources, this was the main ingredient in the poison that Socrates drank to commit suicide after his trial and Athens. It's so corrosive that it can eat holes in solid iron, and yet we expose our bodies to this chemical every time we have a cup of tea or take a shower. Studies have found that trace him of this compound linger in our decomposing bodies, even for months after we die. It is so addictive that the average human cannot at this point survive more than

a few days without receiving a dose. This chemical is called die hydrogen monoxide, and it has already been found in nearly every natural environment on Earth, and if we don't ban it soon, there will not be a single patch of the planet left uncontaminated. Now there are million versions of this, but a lot of them will ask people to kind of sign on and be like, oh, yeah, you know, we've got to get this thing out of

our out of our homes and all that. Yeah, because it's clearly we're talking about something that's a threat to the children, uh, to America, to life as we know it. And it's it's funny because when I think about this prank, so obviously the joke is that what it's talking about is water. And so it's a joke that works on several levels. For one, it's an example of how even technically true statements can be extremely misleading without being put

in the proper context. Uh. And I think it's also just used to sometimes suggest that people should get like better education and chemistry and the natural sciences, which sure, you know, fair enough, I I also wish I was

better educated in chemistry. But I think it's on the other side it it does take advantage of something that is a totally justified anxiety that people have about chemistry in the natural world and especially the modern world, because when we make decisions about deadly risks about physical cause and effect, you know, our intuitions and our knowledge about how things work are are strongly biased towards perceiving physical threats within what you might call like the Newtonian physical domain,

like threats from big moving objects somewhere between the size of a pebble and a landslide. But especially since the Industrial Revolution, the world is also full of chemical threats that are really somewhat invisible in this respect, like they don't really show up on the Newtonian physical domain. And so we've got some natural defenses against chemical threats like this.

We've got our senses of taste and smell, and we have some aversion reactions in like our digestive system or respiration system, like sometimes you detect a noxious chemical and you bar for you start coughing or something. Are our

bodies can can help detect and reject things. But we all know by this point that there are in fact extremely dangerous chemicals that are essentially undetectable to our senses, either because they have no strong smell or taste, or the relevant doses are so tiny that we wouldn't notice them before it's too late, or because maybe they don't have an effect until they've had until you've had extreme

repeated exposure or consumed lots of chemicals. We're gonna be talking about one of the latter today, and so this is the kind of compound that we're going to be getting into, a chemical that has proven fascinating and very useful but also strangely dangerous depending on the context, a sort of Dopple gang or of water, the wetness of the shadow realm. Today, I wanted to talk about heavy water, and it is heavy, literally heavy, But I want to want to say this is not to be confused with

hard water. Uh So, if you're out there, listen, We're talking about heavy water, not hard water. Hard water is just water with a high mineral content. Oh is that what it is? I think I literally didn't know that. Yeah, this is the one that, like you know, that can can mess with how your soap SuDS up, that sort of thing. Okay, uh though some people like it because it makes their hair look good, right or at least? Yeah,

I don't know. It's one of those things. I don't have a lot of experience with it, or maybe really even knowledge of of hard water. So when you brought up this topic, I initially thought you were talking about doing uh an episode or episodes about hard water, but it's not hard water again, heavy water. The washers in

your shower will really rust after this episode. Alright, So for the rest of the episode, we're gonna discuss a few things that that we found interesting about heavy water, its role in the natural world and history, and maybe the question of whether you should drink it. Um So. At the molecular level, as we all know, regular water is made of two hydrogen atoms and one oxygen atom. It's H two O, and this trifled structure makes for a really amazing and powerful polar molecule that acts as

kind of master solvent that makes life itself possible. Every cell in your body depends on the particular chemical properties of this molecule. Without H two oh, nothing in the organic world works. Now. Heavy water is an alternative form of the same molecule, which relies on a different isotope of the hydrogen atom, known as deuterium. A normal hydrogen atom also known as protium just to distinguish it from deuterium,

is composed of two sub atomic particles. So it's got a nucleus that is just one single proton and nothing else that has a positive charge, and then orbiting that it's got one single the electron, which has a negative charge. Deuterium adds a third element to the mix. It adds a single neutron to the nucleus of the hydrogen atom.

Uh Now again, this makes it an isotope of hydrogen, and isotope is a is a version of an atom that has a different than usual number of neutrons in the nucleus, and a new neutron doesn't have a charge, but it does have mass. So an atom of deuterium is almost twice as heavy as an atom of ordinary hydrogen. Deuterium is a stable isotope, and it is found in nature. It's not something that's just a product of the Industrial

Revolution or of nuclear reactors or something like that. It's found all throughout water in the Solar System, it's found all throughout Earth's oceans. Roughly one out of every sixty hydrogen atoms in the ocean is actually deuterium. So if deuterium occurs in nature, you might wonder, well, where does it come from? With most other elements, you can trace their origin to some form of nucleosynthesis within stars or

during high energy events like supernova. However, almost all of the deuterium found in nature is a leftover product of the Big Bang. These atomic nuclei are not generated by stars, or when they are, they're usually destroyed soon after they're created. They've been the way they are for thirteen point eight billion years, and on Earth, one major place to find hydrogen is bound up in water molecules. Uh So, in most ways, deuterium behaves chemically the same as ordinary hydrogen.

So deterium gets locked up into water molecules, uh and it just floats around there in the ocean. The technical name for a water molecule with deuterium in place of hydrogen is deuterium oxide or D two oh. So if you ever seen D two oh written out, that means heavy water water molecule with deuterium instead of regular hydrogen. It's also sometimes called deuterated water, but more commonly it's

just known as heavy water. Now, as I've said, in many ways, deuterium behaves just like protium hydrogen, and so in many ways heavy water blends in with and behaves like regular water. But not in every way. And a lot of what we're gonna be doing in this episodes is exploring some of the fascinating and historically relevant and weird differences between regular water and heavy water. That's right.

So one good place to start here and that the history of the discovery of heavy water is to go back to that's when chemists Author Lamb and Richard Lean of New York University tried to define the density of pure water and they kept getting varying results, which ultimately paved the road for the discovery of isotopes that's variant. Those are variants of particular chemical elements due to differences in neutrons. And then also the discovery of heavy water itself.

And this is key because because again heavy water isn't something that's you know, entirely man made or anything like that. It's in water. It just constitutes one part in four thousand, five hundred. Yes, that that's correct. Now about that number. I was wondering about the ratios here because I saw I've seen that that ratio one hundred, and I've also seen the ratio of one out of every sixty four

hundred um like. For example, of the one important publication on the evidence for the existence of heavy hydrogen back in one which was published in the journal Physical Review, was a letter by the American chemist Harold c. Uri which pegged deuterium as one out of every hydrogen atoms, but I've also seen it published elsewhere that it's it's now thought that at least one out of every sixty four hundred or I think more more like sixty twenty

or sixty four fifty water molecules in Earth's ocean are heavy water. Um. So, I don't know if those numbers represents some kind of conflict, or if one represents a genuine difference in what you'd find in the water molecules in the ocean versus what you'd find just in hydrogen more broadly. I'm not quite sure about that. But the point either way is that uh is that deuterium is found in nature, but only in a in a very small proportion of hydrogen, and thus heavy water is found

in nature, but only in a very small proportion. It's one out of thousands of molecules. Yeah, so it's kind of like if we had like a cash only society and you had some heavy nickels floating, they're right where the nickel itself like, it's it's not it's not worth more, it's not it's still just worth five cents, And factors into the figuring that way. But you can imagine scenarios where extra heavy nickels in enough. Uh you know, if there are enough of them within a larger amount of nickels,

that could have an impact on things, etcetera. Or if you get into a situation sort of. This will discuss where people are like, oh man, these heavy nickels are great, I've got to get more of them. Can I like syst them out of the existing uh cash population of the existing world nickels. Can I make normal nickels into heavy nickels, etcetera. That's very good, Yeah, and you could.

I can imagine you'd run into unfore seen problems if you suddenly decided you wanted to base your entire economy on heavy nickels, or I don't know, maybe a third of your economy. Uh. That'll tie into something we get into in a minute. So I mentioned him just a minute ago, that the American chemist Harold c Ury. I hope I'm saying his name right, you are e y Uh. He's a very important figure in the discovery of deuterium.

He usually gets credit along with his collaborators for proving the existence of deuterium through spectroscopic experiments in nineteen thirty one, and he received the Nobel Prize for his discovery in nineteen thirty four. But I thought it would be useful to just look at a couple of the physical properties of heavy water. So one of the key differences between heavy water and ordinary water is that heavy water is literally heavier because of the extra neutrons in the deuterium.

You remember, a deuterium atom is almost twice as heavy as a regular hydrogen atom. Because of that, D two oh is about ten heavier than an equal quantity of regular water. And you might wonder, a wait a minute, wy only ten percent heavier rather than double the weight. We'll remember oxygen with eight protons and eight neutrons, makes up the bulk of the mass of a normal water molecule.

It's got oxygen and then the lighter hydrogen atom. So you're only increasing the weight of UH two of the three atoms and the two smaller ones in the water molecule. So so it's ten percent heavier. And this results in some very interesting party trick potential. For example, regular ice always floats in water, but with deuterium, if you make a heavy water ice cube, it will sink in water because it's got a greater density than the surrounding water. Also,

heavy water is more viscous than regular water. It's a little bit. Uh, it's gonna be a little bit more like a like a jelly and maybe not to a you know, physically perceptible extent if you were to hold it in your hands, but it is more viscous, which would probably have measurable effects if say, the oceans were entirely made of deuterior m. Yes, and this is this is a great question that that had been asked on the Internet already. I think it originally showed up in

a as a Cora question. Uh, what would the ocean be like if it was made out of heavy water? And uh, and is sometimes the case on Cora. You had a really insightful answer pop up, this one from Josh Velson, chemical engineering consultant for bio and petro chemicals. And it was such a neat answer that it was actually featured on Slate as well. Uh, so I recommend checking that out. But but I want to touch on some of the main points that Nelson makes, and I want to stress this would be if there was a

magical instant change, you know, like snap your fingers. Now, our oceans are just all heavy water, so it's not a realistic scenario, but it's one of those thought experiment scenarios that I think helps to underline what we're talking about here with heavy water and how it affects it

would affect, you know, various systems. So, first of all, since any given portion of the water uh out there in the oceans would be ten point six percent heavier, Velson says that anything swimming outside of its pressure zone would basically be instantly crushed. Now we've discussed on the show before. However, you take certain deep sea organisms and you bring them up into shallower waters, you have some

exploding effects that take place. And likewise, if you take something from shallower waters and plunge it down into the depths, there can be a crushing scenario. But this just means everything that these sort of things would be uh far more exaggerated. Yeah, I didn't even consider this, But so if the ocean is suddenly about ten percent heavier at the molecular level, the pressure at the bottom of the

ocean would also be a lot higher. So so you're suddenly down there and it's like somebody's just like put an extra backpack on you. Yeah. Absolutely. Also, Velson says that everything floating in the ocean would displace more mass, so ships would need extra ballast to stay at the same level in a heavy water ocean. And then this is interesting, Velson writes, quote a large portion of the oceans would freeze instantly due to a higher freezing point.

This would release a lot of heat into the atmosphere in the polar regions, causing a massive imbalance and resulting in some pretty spectacular polar cyclones unquote. Well, and then on top of this, the mass of the planet would change. This would alter the Moon's orbit, and basically it would just mess with weather and climate in a major way, resulting in earthquakes, tidal way, it's rising sea levels. But of course, to change the ocean is to change life

as well. So we'll come back to this, and I'll come back to Nelson's points in a bit, all right, So, I know what you out there are already wondering, Should I drink it heavy water? Should I should? I? You know, get a big bucket of it and just gulp, gulp, gulp. It sounds like the the ultimate metal head like bottled water, right, heavy water. Oh yeah, they would sell it at the metal shows. That's really good. So there's actually a great article about the history of drinking heavy water in the

journal Nature Chemistry by the American chemist Michelle Francel. We actually quoted a piece by her, uh at some point in the past year, because she wrote a thing that we did for Cupid's leadon narrow That was it. She wrote an article about the history of sugar of lead as it was used in ancient Rome. That was really good. But this piece is called the Weight of Water. So

it was published in Nature Chemistry in twenty nineteen. So she begins the story in nineteen thirteen talking about when the Hungarian chemist George to Heavish was visiting the lab of Ernest Rutherford in Manchester, England. Now, eventually both of these scientists would have Nobel Prizes for their discoveries, but at this point Rutherford was the was the senior scientist, and Heavis she was more of a young student, you know. He was still learned in the ropes. And Rutherford had

given Heavish a task here. He wanted to get him to take quantity of lead and find a way to chemically isolate all of the radioactive atoms of what was then known as radium D from the lead and this sample, and he Is she was unable to find a way to do this because what they were calling radium D was actually not radium but a radioactive isotope of lead

that is now known as lead to tin. But in the process of working on this problem that he never ended up solving, he Is she realized a potentially very interesting implication of this failure. When a sample contains a radioisotope, a radioactive atom within a massive other atoms, you can use these radioactive atoms to track the movement of a

chemical through a biological system. So, for example, if you're curious how lead in the soil is taken up by bean plants and then distributed around the plant's body, you can spike the soil with radioactive isotopes of lead, so the plant will take them up. Because they're still lead, it will treat him the way it normally treats lead. But because they're radioactive they're radioisotopes, you can track what

the plant is doing them with them. You can use equipment to track exactly how these isotopes are metabolized through the roots. The stem the leaves. Uh. And you can also use these radioactive tracers to track the absorption and elimination of elements in animal bodies. So you could find out, well, when when somebody ingests lead, does the body immediately purge it or does the lead stick around? How long does it take the body to purge it? Where does it

go in the body? And it turns out you can use radioactive tracers to find out lots of things about what's going on in the body, not just in basic biological research, but actually in medicine. Radioactive tracers are used in medicine all the time. Now Here, I wanted to mention a couple of anecdotes that came across about Heavishet that are really interesting. He seems like a kind of mythic hero in a way, a sort of Romulus or Gilgamesh here, or maybe we should say Bill Gamesh, Uh

Bill Gamesh to heav is she? So there were a couple of the most popular stories about his life that that I I couldn't pass up mentioning. The first one I found recounted in a short historical article in the Journal of Nuclear Cardiology, and it concerns how heavy she first demonstrated that tracer principle that I was just talking about. So this is by Strauss at all uh from and the authors here talk about while heav is she was working in Manchester in this lab in the early nineteen tens.

He was living at a boarding house that had been recommended to him by Rutherford by the way. So his boss is like, hey live in this place, and apparently it was just miserable there, heavs. She started noticing that he didn't just hate his lodgings, he really hated the food at his boarding house. He had a sensitive stomach, he suffered from indigestion, and he started to suspect something

was going on. What he thought was happening was that, uh, now this is an old school boy earning house, right, so they give you not just a bed, but a bed and your daily meals. And he started to suspect that his landlady was recycling food. So you know, she makes you a great r bee frost and then you eat a little bit of it and you don't finish it.

There's some still on your plate. He is. She suspected that the landlady was just taking whatever you couldn't finish off of your plate and then taking it back to the kitchen and then mixing it up and serving it again in some disguised form the next day. Well, that's

just being a good mom. You know. You can appreciate, you know, of refraining from food waste here, But he is she was not happy with it, because I think the problem was the beef was already suffering from freshness problems and was was being recycled to the point of possible food poisoning. So at some point, uh he called. He brought this up with his landlady to read from the article here quote. His suggestion that she served slee prepared meat more than once a week was met with indignation.

How could he, she insisted, accuse her of serving anything but the freshest of ingredients. Uh, so have is? She decided to put this claim to the test using a really amazing method, in fact, using some of the exact same techniques that he had just been discovering recently in Rutherford's lab that we were just talking about. So one Sunday, when he she had eaten as much as he could, he secretly spiked the food left on his plate with a number of radioactive isotopes, and I'm just going to

read from the article here quote. A few days later, the electroscope he smuggled into the dining room revealed the presence of the tracer, radioactive hash. Confronted with the irrefutable evidence, all the landlady could do was exclaimed, this is magic. The first radio tracer investigation had successfully followed leftover meat from the Sunday meal to the kitchen meat grinder, into the hashpot, and back into the dining room table. So

when in doubt, you know, spike your food with radio isotopes. Truly, this is one of the great adventures in science right here. There's actually a much higher stakes one though. Uh. That's the story about Heaves. She's life from World War two. So, uh, there's a there's a great NPR piece about this from two thousand eleven by Robert Cruel, which that I'm relying on here. I can't say the title or it will

ruin the story, but it goes like this. So in the summer of nineteen forty, Heaves she was working at an institute in Copenhagen, in the laboratory of the great physicist Niels Bore Uh Denmark had been invaded by the Nazis earlier that year. I think that was in April of nineteen forty, and it was now occupied with German troops raiding homes and marching in the streets. And they just arrived in Copenhagen later in the summer when the story takes place. So at the time, Nils Bore is

in possession of two gold medals. They are Nobel prizes in fact, which are made of twenty three carrot gold, but they're not his. They belonged to two German physicists, Max von Laua and James Frank, who were both at risk within Germany. Frank himself was Jewish and von Laua was not, but he was known for his very fierce opposition to the Nazi Party. Now they had sent their Nobel medals secretly to Boor's Institute for safe keeping. But

here we're faced with a problem. At the time, Germany was at war and it was actually illegal to remove gold from the country. So by sending their gold medals to Boor's lab, Frank and von Laua had committed what would probably be a capital offense back home, and worse, it couldn't really be covered up because their names were

engraved on the gold medals. So Boor and his colleagues were thinking, oh no, if if our institute is raided and uh, it probably will be Born knew his lab would be searched because it was known to be a safe haven for Jewish scientists and and other people opposed to the no Zis who were fleeing fleeing the Nazis. They had come to his institute and now they were occupied.

Um so Bore realized they had to do something to hide these medals because if they were discovered, you know, these scientists back in Germany would probably be put to death. So Boor and his colleague at the time, Heavish, discussed their options. They thought about maybe we could bury it, bury it in the gardens, but they worried that the Nazis would dig all over the grounds and probably find them. And then heavs she came up with an amazing solution,

uh literally, a solution dissolve the metals. This was not easy, since gold is not very reactive. It's difficult to dissolve but heavy she knew that there was a solution that would do the trick known as aqua reggia which is a mixture of hydrochloric acid and nitric acid and a three to one ratio usually. So here I just want

to read from the NPR piece. Heavish and his autobiography says, because gold is quote exceedingly unreactive and difficult to dissolve, it was slow going, but as the minutes ticked down, both medals were reduced to a colorless solution that turned faintly peach and then bright orange. By the time the Nazis arrived, both awards had liquefied inside a flask that

was then stashed on a high laboratory shelf. Then, says science writer and Radio Lab contributor Sam Keene in his book The Disappearing Spoon, quote, when the Nazis ransacked Boars Institute, they scoured the building for loot or evidence of wrongdoing, but left the beaker of orange Aqua regia untouched. Heavy she was forced to flee to Stockholm in nineteen forty three, but when he returned to his battered laboratory on v Day, he found the innocuous beaker undisturbed on a shelf. And

there's a codage of the story that's pretty interesting. So after the war was over. Heavy She again used chemistry to re extract the same gold from the beakers, had that sent to Stockholm, where it was reformed into new medals that were again presented to the original recipients. Interesting, I mean, kind of unnecessary. I guess that the same gold to actually go back to create the you know, the the same awards, but still neat for it's got

that magic thing. You know, people always want to like melt down a symbol of one thing and turn it into another. I guess in this case, it was melting down a symbol of one thing and turning it back into itself, but still has some of the same kind of symbolic weight there. Yeah, there's kind of a you know, sitcom level um circular motion to the whole thing. Right, we come back at the end of the day, we still have the same awards again, they've been reformed into

the same thing we're familiar with. Yeah, totally. But coming back from from those anecdotes so so so now we've got an idea of heaves She the character he as She the mythic hero, his life actually also ties into

heavy Water. So there was one day in Manchester in the early nineteen tens where Heavy she was having a cup of tea with the English physicist Henry Moseley, and at the time Heavy she was pursuing his radioactive tracer experiments with plants, the ones that I was talking about earlier, like the plants and seeing how they take up lead

and and all that. Uh So, the idea was again that you could learn how elements from the soil are metabolized in plant bodies by studying this with with radioactive tracers. And apparently Heavy she and Moseley, we're getting all riled up about this idea, and heavs She posed a question about whether it would be possible to ever mark the water molecules in a cup of tea with some kind of tracer that could track those molecules throughout the human body. And at the time they did not know of a

way to do this with water molecules. But a couple of decades later, chemistry would come around with an answer in the form of discoveries by Harold Yuri, which we talked about previously, of heavy water. So not long after the existence of heavy water based on deuterium was confirmed in the lab, a number of world class scientists decided well, to hell with it, you know, let's let's put it in our mouths and see what happens. Was it was

a different time of experimental regimes. And it's also funny because if you read the scientific papers of the time, often they're just like a paragraph long. They're just like, here's what we did, here's what it tasted like. Nobody died. So in the year ninety four, Herald Ury sent George to heavs She a sample of water that had been

enriched to zero point five percent utterations. Remember, five percent of this water is still the regular stuff, but this would nevertheless represent a much higher concentration of heavy water than a normal glass, right, And that percentage is worth keeping in mind for later when we're talking about higher percentages in the human body. Right. So he is She and his assistant Eric Hawford decided to test the effects

of a deuterium enriched aquatic environment on goldfish. So they took twenty small goldfish and immerse them temporarily but for

steadily increasing periods of time in the deuterated water. Uh And so, to read from francel here quote, the overcrowded goldfish rapidly exchanged water with the deutorated water in the bowl, which became miserably less dense, noting no change in the behavior of the zero point two percent deutorated goldfish, though how this might be assessed with so many goldfish stuffed into a small glass for up to fifteen hours at

a time is unclear. Heavy She apparently concluded it was safe to drink the heavy water and proceeded to run the experiment he described Mosley twenty years before. So the rationale here is, Okay, it seems good enough for a goldfish, good enough for me, I'm going to try it too well. But I like that France Will brings up again, Like it's not exactly clear how they were judging what the effects on goldfish were, given that they were like cramming lots of goldfish in a very small container of water.

I guess they observed that the goldfish were not dead, right, I mean, if you're looking for them to like die instantly or explode or something. Yeah, So it's not clear exactly whether heavy She or Hoeford did the drinking, but one of them did, and they consumed a couple of

the samples. They collected the heavy water from the drinker's urine, distilled it and measured its density, and about twenty minutes after the chugging deudated water started showing up in the urine and In this experiment heavy She and Hoverer found that the average molecule of swallowed water lingers in a human body a lot longer than it lingers in goldfish and humans. The metabolic half life of a dose of water is about nine days according to this test at least.

But the big question I guess is were they okay? Well, if not, they didn't report anything. There was no sickness, also no notes about what the water tasted like. So after heavys She and Hofer published their paper on deuterium as a tracer for water and animal bodies, another professor decided to follow up by by addressing the question of

toxicity head on. Now, obviously, whichever one of the the h is drank the heavy water was all right, But this wasn't an extremely deluded form was a small amount of it. A professor named Klaus Hanson of Oslo University performed a toxicity test on himself in front of an audience including the press and a bunch of medical professionals with equipment standing by like stomach pumps and stuff, and Hanson swallowed what Francill characterizes as a quote scant teaspoonful

of heavy water. Now it turned out the life support equipment was not needed. Hansen was fine, though he did report what he called a dry burning sensation after swallowing um. And then Harold c Uri at Columbia University and his colleague Geno Faila decided to follow up on this by staging a blind taste test. So this is gonna be like the Pepsi challenge, but for juteri um uh. And they published the results in nineteen thirty five in a

paper called Concerning the Taste of Heavy Water. As I mentioned, sometimes papers were very short back then, so I can actually just read the entire second paragraph of their paper here Tasting notes for heavy water. Right, Okay, so here's what they said. In order to make the experiment as objective as possible, a third person in a different room

prepared the samples to be tasted. Each of us was then given two identical watch glasses, one containing one cubic centimeter of ordinary distilled water and the other the same amount of pure heavy water, especially prepared for biological experiments. One of us kept each sample in his mouth for a short time to make sure of its taste, then spat it out. The other repeated the same procedure, but

swallowed the water. Neither of us could detect the slightest difference between the taste of ordinary distilled water and the taste of pure heavy water. It might be mentioned in this connection that one cubic centimeter of water is not too small an amount to taste properly. Since both of us could detect plainly the characteristic flat taste of distilled water in both cases, it may be concluded therefore, that

pure deuterium oxide has the same taste as ordinary distilled water. UM. Now, this is funny because I've read some more recent studies. I think one that was that I found in a preprint server that has not been published yet that claims that they've redone this taste test and decided that that heavy water is noticeably sweeter. So they're disagreeing with Uri and Fila here. I'm not sure how to sort that out.

But one of the things about these taste tests that Francill points out is that they were ridiculously expensive because at the time, the scant teaspoonful of heavy water that Klaus Hansen swallowed probably cost the equivalent of about a hundred thousand dollars in current US dollars. Uh. So, I don't know if that's a good use of experimental resources. Uh, it's probably It's probably not surprising that Urie found these

human experiments wasteful, even though he did one. After all, So like, if a scant teaspoonful is a hundred thousand dollars worth of product, you know, and a teaspoonful water is a vanishingly small sample compared to how much water is in an adult human body, it's probably just gonna be prohibited of ly expensive to do toxicity experiments on a human being with with this stuff. Yeah, I mean this seems even above and beyond iracous prices for water, right,

I mean this is crazy, Yeah, exactly. You make yourself a heavy water still suit, don't don't lose a drop. So if you were trying to understand the physiological effects of heavy water at scale, you would need to test it on a much smaller organism. And eventually some research of this was carried out to figure out exactly what deuterated water does to plant and animal bodies that the more research of this kind was done throughout the twentieth century.

A study in nineteen thirty six by Henry Barber and Jane Trace found that heavy water was in fact quite lethal if it could replace about of the water in in the body. And I think this was determined with with small mammals like mice um and this is sometimes shorthanded to about one third. There there are various percentages that are given, but basically you do not want one third to you know, half of your body water replaced

by deuterated water. This creates immense problems. Um replacement of ordinary water with heavy water seems to kill the mammalian body once you pass certain thresholds by primarily interfering with mitosis or cell division, and in this way its effects are strangely similar to what you would see with large

doses of chemotherapy. Metabolism slows down and cells stop dividing and reproducing, and this can lead to of course sterility and in the reproductive system, but also interior degradation of the function of multiple organs throughout the body and a kind of cytotoxic collapse before death. UH the chemical principle that's responsible for this is known as the kinetic isotope effect, so I'll try to do the simple version as best to understand it. Again, deuterium is chemically pretty much the

same as regular hydrogen. It's got the same charge, the same proton and electron, but because of the heavier nucleus um, even though it will usually engage in the same chemical reactions, there is a tendency for the changes in the isotopic

composition to affect the rate of chemical reactions. So even though dto O is chemically a lot like regular H two oh, it's heavy hydrogen forms stronger bonds with the oxygen atoms in the water molecules than regular protium does, and this means it's harder than usual to break up heavy water molecules into their constituent parts, which in turn means lots of chemical reactions happen more slowly, and this starts to consistently slow down chemical reactions throughout the body

if you replace too much of the water in your body with D two oh. If there's too much of it and chemical reactions get slowed down too much, all hell breaks loose cells don't divide, and there there's a kind of there are kinds of systemic collapse that that just come from this. So heavy water makes for a very strange, a peculiar type of poison. You know, from everything I've been reading, it's something that is usually harmless

at doses of even probably a glassful. But if you can really load somebody up with heavy water to the extent that it replaces somewhere between twenty five and of the water in their body, it will absolutely kill them in a horrific way. It is a ridiculously expensive way to try and assassinate somebody, So I'm I'm kind of shocked it hasn't been done in a James Bond film. This seems perfect for the Bond world. That's a very

good point. Now, I think heavy water is not going to be nearly as expensive as it was when those first taste test experiments were done, but still, I mean, yeah, it would be. It would be a needlessly elaborate method of assassination. I mean, surely one of those c s I shows considered it at some point. Maybe they did it. I mean, I'd I'd love to hear from anybody if if they if you have seen a heavy water murder episode of some sort of episodic detective show. I'd like

to hear about it. Well, this does tie into one particular example that Francile Sites in her article. Uh that no one was killed fortunately in this example, but there was an instance of of heavy water poisoning. Though the heavy water turns out to be not necessarily the the important part of the story. So there was an Associated Press article from March five Francile Sites, and I went and looked up the original article. It's called power plant

worker accused of spiking cooler with radioactive water. This happened in in Canada, so it's a dateline New Brunswick. And uh, just to read the lead here quote a nuclear power plant worker was charged Monday with spiking a lunch room cooler with radioactive water that eight men drank before the contamination was discovered. The eight who drank the contaminated water last month that the point Lapro plant have have a slightly higher chance of getting cancer, officials said, but are

in no immediate health danger. Uh. And the article goes on to characterize this is probably some kind of practical oak gone awry. Does not seem like a very good joke. Again, no one died immediately from this, though, the person who spiked the water was charged with a crime. Uh. And this does tie into an interesting misconception, which is that heavy water is naturally radioactive and heavy water it's not.

Deuterated water is not naturally radioactive unless it's been made radioactive by, say by for example, like being the cool and around a nuclear reactor. UM. Now, water with hydrogen three, remember heavy water is the kind we've been talking about, is with hydrogen two. Deuterium water with hydrogen three, also known as tritium, would be another story. It is definitely radioactive in all its forms, but far far less common in nature. So if you were to drink heavy water,

it would not naturally be a radioactivity risk. It would be this poisoning risk if you drank enough of it and it replaced enough of the water in your body. Right. And and that kind of brings us back to that Velson q and A that was published in Slate that I mentioned earlier. You know, you instantly replaced the world's oceans with heavy water, where you have these immediate concerns.

But then obviously that water is going to make its way into organisms, and so Velson writes, you know that basically, the biological concerns here would start out UH milder. You know, it would be more about bloat and weight, lower blood pressure. But by the time you reached like the tent heavy water mark in particularly in humans, we would be just irreversibly sterile. And then certainly by the time you hit that fifty percent point, I mean, that's that's definitely in

the fatal zone. UH. So you know, Velson writes that, you know that heavy water makes UH eukaryotic cell division impossible due to the impact on the my mitotic spindle, so most multicellular eukaryotic life would just snuff it extinct within a few years. Yeah, I was looking at some some possible exceptions. There are interestingly, UH organisms that are heavy water tolerant, or much more heavy water tolerant than

other organisms. So prokaryotes, I think, in general, are more tolerant of of being exposed to deutorated water than eukaryotes are. Bacteria are going to be better off, and maybe they could just like you know, re evolve new complex life forms in the UH in the deutorated world. I wonder if they would be like slower moving life forms because the deutorated earth would just like have slower chemical reactions in general. Well, you know, I did a lot. I

was thinking the same things. I was looking around a lot to find some examples that are, you know, some sci fi visions of what heavy water organisms might consist of, and and I was not able to find anything. But I did find some some stuff about the idea of of of heavy water organisms that have would have would be cultivated for their use in magnetic resonant studies. And

these were proposed back in the late nineteen sixties. These would again be cultivated versions of natural world world organism is that um in their heavy form would not be found anywhere in the natural world, so as proposed by Cats and Crespy in us in the journal Science back in nineteen sixty six. There various uses and products one could derive from their cultivation. Higher plants and even simple organisms like you mentioned can resist full deuteration, but there

are possibilities for other life forms. So so some of the main benefits here would be their use in studying UH heavy water isotopes, you know, following the path of hydrogen in biological systems. UH deuterated algae, for instance, which we've had since the nineteen sixties have a useful role in the study of photosynthesis. But um, yeah, I wish I could have found something about like the idea of the deuterated man heavy water, heavy water elephants or something

like that, But I didn't find anything. That's how we get Middle Earth's sort of a chemical recycling event and and and ended up there. Um. I did find one example that I was looking at. Apparently there's some kind of nematode worm that can survive and reproduce in almost pure, pure deuterated water. Interesting, there's always a worm. That should be a slogan of this show. You know, whatever you're saying about biology, it's like it's true in most cases,

but there's always a worm. Thank you, thank you. Thank Now there's another way that heavy water has been very important, and that's in the history and development of nuclear technology, and um, in developing nuclear reactors and in the history of the development of nuclear weapons. Yeah, this is all interesting, you know, looking at the twentieth century certainly a time in which our understanding of chemistry greatly evolved, and then of course we began to understand uh nuclear fission as well,

and scientists around this time, so nuclear fission. Uh. This was a discovered in December of night. Around this time, scientists began to realize that heavy water could be as what is called a moderator. So in nuclear reactors, a moderator slows down the neutrons to speeds at which fission can occur. Uh. It helps to create the conditions in which a true fission chain reaction can occur and keep going.

So a nuclear reactor using heavy water can make use of naturally occurring uranium rather than enriched in ranium, because again, you can't just kick a bunch of naturally occurring uranium and produce an atomic blast. So basically, scientists in Germany and in the UK they realized kind of early on what heavy water could potentially do. Now, an interesting wrinkle here is that the US atomic weapons program ended up depending far more on graphite as a moderator than heavy water.

But the Germans came to believe that graphite wouldn't cut it, so they focused on heavy water. UM. Heavy water was obtained by um electrolysis, and a leading facility producing it was norways of the more facility, So the French and

the Germans both attempted to buy the entire stock. I think the Germans had purchased some, but then there uh for the French and the Germans both were like, we want to buy it all, and aware of the military possibilities, Norway, which was at that point neutral, sold it all to France and and it was smuggled out of the country.

In that same year, however, the Germans took Norway and the plant became a military target for the Allies because, of course, the whole situation here is it suspected that Germany is working on creating an atomic weapon, right, and so the idea and they didn't know exactly how things would shake out, but it looked at the time like heavy water might be a really crucial element in achieving nuclear weapons, right, and so there was obvious like terror among the Allies that like, oh no, if they get

their hands on too much heavy water, they could build a nuclear reactor that could potentially lead to weapons capabilities or whatever before we achieved them. So it's again it's a one ring scenario. It's like, you know, give us the weapon of the enemy, don't let them have it, right, Yeah, So, as a result, this facility was targeted five different times UM by the Norwegian Special Forces, by the r a F, by the British Army, by the US Air Force, and

by the Norwegian Resistance. And these were efforts again to try and prevent the Germans from developing an atomic weapon UM. Operation Gunner's Side was a particular note. In this one, four Norwegian agents parachuted into the area. They joined up with four special agents of Special Forces agents that had been deployed earlier on a recon miss mission, and they all attacked the plant, destroying the heavy water section of the plant and costing the Germans something like fives of

heavy water. I think these missions had no casualties. Also, well, these two missions that have mentioned here had no casualties. There was one of the attempts UM ended up involving a plane crash and the the agents involved were executed by the Germans. But but this particular mission, I think, yeah, you're correct on UM. Now it would ultimately turn out that the Germans were not nearly as close as suspected UM.

But this certainly put a dent in their efforts. Basically, the immediate demands of the war, combined with the efforts by a resistance and special Forces here basically kept the nuclear program of the of Germany in a kind of preliminary stage. But of course the Allies did not know this. They just they just knew that some effort was underway

and it needed to be curved. Now, in more recent years, there are all kinds of interesting uses that have been discovered for deuterium and UH and heavy water that might not have even been imagined early on, or maybe some of which were imagined early on, but nobody knew if they would ever be achieved. One of the examples that I was just recently looking at is this interesting idea of deuterated drugs, apparently the first one of which was approved by the f d A in seventeen, but it's

an idea that's been around for a long time. Yeah, I think the first patent was granted back in the nineteen seventies. Um, so yeah, it's interesting. Now, before anyone assumes this has anything to do with turning your water heavy or any sort of thing, the basic idea of these UH deuterated drugs is that the resulting drug has a longer half life due to lower rates of metabolism. So half life when we're talking about medication. It's it's the point at which it loses fifty of its effectiveness

inside your body. So this isn't related to say shelf life. Uh, it's about how the drug functions in the body itself, right, so it can like act more slowly over a longer period of time. Yeah. Um, And it's funny because we've talked about several different ways now. Essentially one of the ways that delorated water will kill you if you drink too much of it is it slows down metabolism and chemical reactions cell division in your body to a point

where you can't survive anymore. But there are more moderated forms of consuming heavy water that people have long speculated, whether rightly or not. I mean, there is still an open question as to whether there's anything to these ideas, but have speculated that, well, maybe you could use this to slow down chemical reactions in the body in a good way, in a way that's actually desirable, such as in life extension or you know, human hibernation or things

like that. So I wanted to read apart from in Francel's article where she says, quote Mounta banks have been promoting heavy water as a panacea almost since the moment you're re isolated the first sample. Even imminent chemists have not been immune. In a nineteen thirty seven Popular Science article, Chemiss James Kendall opined that the elderly might extend their

lives by drinking heavy water. Quote the heavy water drinkers reactions would probably be slowed and possibly his mental processes also. But who wants to be fast at sixty Well, I mean, I guess you know sixty was there's a different sixty seven, I guess. But so the idea here is just don't drink too much of it, Drink a balance of it, and you'll be okay. It's kind of a never finish your second drink approach to life. Yes, now, I want to be extremely clear, we are not advocating that anyone

do this, nor claiming that this would be effective. But it is something that people have continued to speculate about. So that one article that Francial references in her article is by A. Zion Lee and Michael P. Snyder and bio essays in that is a it's a speculative article that explores this question. It's called quote can heavy isotopes increased lifespan studies of relative abundance and various organisms reveal

chemical perspectives on aging. Now they sit again some of the same stuff we've been talking about, the the chemistry of the kinetic isotope effects which slow down chemical reactions, and this sort of slows down all kinds of processes that happened in the body that are in a way that they are metabolic processes that are associated with the

advancing of age. And so the authors here right quote previous isotope analyses have recorded pervasive enrichment or depletion of heavy isotopes in various organisms, strongly supporting the capability of biological systems to distinguish different isotopes. This capability has recently been found to lead to general decline of heavy isotopes in metabolites during yeast aging. Conversely, supplementing heavy isotopes and

growth medium promotes longevity. Whether this observation prevails in other organisms is not known, but it potentially bears promise in promoting human longevity. So some of the ideas explored here. The implications would be that you could possibly ingest certain amounts of heavy water to trigger um UH, to trigger a sort of state of hibernation, which could be useful

and say like interstellar travel. Francill points that out um but also as summarized by Francill, basically they're observation is that quote Yeast models have showed that heavier isotopes, including deuterium, become depleted in organisms with aging. They suggested as possible that periodically supplementing the diet with appropriate isotopeologus could extend

human lifespans. So if like you, tend to lose deuterium as you get older, maybe supplementing the body with some some you know, a little bit of extra heavy water, a little bit of extra deuterium might do you some good. Again, totally speculative, not proven, but there are there are some interesting tidbits in other organisms that suggests the possibility here.

So in the future, the idea of saying heavy water supplements are possible, even if you end up having to buy them from Goop as opposed to anywhere, right, I mean, I guess the question would be like, is this gonna end up being science based medicine or is this going to end up being some some pseudoscientific miracle cure hawked on you know whatever. Conspiracy theory show um. But either

way you're it's going to be for sale. Now. An inn resting thing I ran across Joe was that UM Apparently by by you can look at Mars, and by looking at the ratio between deudorated water and normal water on Mars, scientists are able to get a better picture of how much water Mars lost in the past. So basically, the more heavy water present, which is harder to lose,

than the more water you lost over time. So to come back to that idea of like heavy nickels and normal nickels in your like personal Scrooge McDuck bank, if you were afraid that lepri cons we're stealing your nickels and lepricns are incapable of carrying them the heavier heavy nickels, then you could go to your Scrooge McDuck vault and you look in there and you count the heavy nickels, and you could you could determine how many normal nickels

have been stolen by lepricns based on the resulting ratio. That's really cool, and I love your analogy, by the way, but this does highlight the way that even if it turns out that you know, deudorde water is not going to extend human lifespans or anything like that. I think deuterium and heavy water will absolutely remain extremely important scientific atoms and molecules for for research because there are a

secondary indicator of all kinds of things. You can find out a lot about the world by looking at at heavy water content and how it behaves. Yeah, I just wish I could have found a heavy water alien. I really wanted to find some somebody talking about heavy water aliens and heavy water people. So well, hey, that's that's open field. Somebody somebody set up a homestead there. Yeah, yeah,

somebody right about it. Now. The one thing that is kind of related to all this in science fiction is that you have had some some some science fiction writers who have dealt with various proposed alternate versions of water.

So author and National geographic journalist Robert C. O'Brien, who lived nineteen eighteen through nineteen seventy three, uh, most famous as being the author of Ms. Frisbee and the Rats of Nim, wrote in nineteen seventy two novel titled A Report from Group seventeen, and it has a lot to do with Nazi plots and a form of water that essentially brainwashes individuals. So heavy water apparently might have played a role in this idea, along with this concept of

polly water. This was a hypothesized, uh, polymerized form of water. They would have been kind of like a syrup, you know again, I mean more viscous. It doesn't actually exist, but it also infloy The idea of it also influenced Kurt Vonnicut's Ice nine concept and Cat's Cradle. Oh yeah, and for those not familiar, Ice nine one of the great plot devices of all time. It's a it's an alternate form of the water molecule that freezes at room temperature,

and it can act as a seed crystal. So basically the premises you drop this in a lake and suddenly the entire lake will freeze at room temperature. It's bad. It's bad and doesn't exist. Uh, unlike heavy water, which is which does exist and is in you right now. Yeah, that's the interesting thing. Um, it's weird how reading about this, uh, and I keep thinking about heavy water holding these uh

opposing ideas in my head at the same time. I guess it's like an exercise in scientific negative capability because I keep thinking of heavy water simultaneously as something that's natural, found in all the oceans of the world. It's in your body right now. It's gonna be harmless at the levels that you ingested, but also is like a horrific poison,

if you know, if ingested in the wrong way. Yeah, I mean, of course, we we often have to think about that in terms of a lot of different things, including just normal water, right, I mean, um, as well as like various household spices, um, you know, moderation and all things. Right, I mean, that's what holds the world

to get holds their bodies together. Just dealing with without any you know, ethical interpretations of the statement like there is a there is a balance, there's a chemical balance in all things, and that's kind of I mean, that's kind of one of the big take homes of the

chemical revolution. In addition to you know, developing all these chemicals of life and then also these chemicals of death during the twentieth century, you know, just are are our sudden you know, increasing understanding of just all of these little bonds that hold us together. Extremely good point. One last thing I'll just say again, don't start buying heavy water for life extension unless it's actually backed up by science.

Correct check the research on that. All right, Well, again, we would love to hear from everyone out there about heavy water. If you have any experience with heavy water, thoughts on heavy water, or indeed have you if you have read science fiction or had any kind of science fiction based thoughts around heavy water organisms, we would love to hear from you. In the meantime, if you would like to check out other episodes of Stuff to Blow your Mind, you can find us wherever you get your

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