Deuterium as a trace isotope?

Most of the elements in the first four rows of the periodic (other than the noble gases) have some biological role – which means that you need at least a little. In many cases, we know something about the specific molecules involved (like cobalt in vitamin B12). In others, we know that lab animals or plants that are totally deprived of that element suffer, without knowing exactly why. Occasionally another is discovered: last year they found out that bromine is essential in collagen synthesis.

I said deuterium might be bad for you – and that might be so. Important if true. But since its chemical properties are somewhat different from ordinary hydrogen, more likely than not it has a specific biological role, which would mean that you need it. That’s more interesting than possible toxicity – less important, but more interesting. It introduces the possibility of trace isotopes, the analogs of biological trace elements: deuterium is the most likely one, but you might want to check out carbon, nitrogen, and oxygen too.

Of course being necessary does not mean that it can’t be toxic: quite a few necessary trace elements are toxic at higher dosage.

G. N. Lewis, no slouch, wondered about this possibility back in 1934. As yet nobody has systemically looked for a specific biological role for deuterium. Someone should.

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26 Responses to Deuterium as a trace isotope?

  1. Tritium and Deuterium are the two heavier isotopes of hydrogen. This change is brought about by adding neutrons to their structure. They are chemically still almost identical to hydrogen and can combine with oxygen to make water. They do react differently on an atomic level. Both are naturally occurring materials. Tritium is very slightly, and weakly radioactive but deuterium is not radioactive. Both tritium water and deuterium water exist naturally in the environment and can only be separated from normal or “light” water with great expense and effort.

    Most of us remember the term “heavy water”. This is water where the hydrogen has been replaced with deuterium. It is used in some nuclear reactors to surround the fuel. In this case it carries heat away and also slows down the neutrons emitted from the fuel so they can be recaptured by the fuel to promote the chain reaction. While normal, “light”, water will do the same thing, the use of heavy water makes the design of the power plant much easier but is not absolutely necessary.

    In sufficient quantity, both tritium and deuterium are toxic. This effect is most widely known for tritium and is called “tritium toxicity”. The effect is characterized by a slowing of the transfer of water across the cell membranes and overall slowing of all neurological and metabolic processes due to slight changes in chemical reaction rates in the body. Very high prompt exposure to tritium gas and water is normally treated by aggressive hydration therapy. This used to be accomplished by alternating doses of beer, coffee, and glasses of water.

    The question as to the effects of low-level deuterium exposure is interesting. Because instruments such as magnetic resonance imaging can detect the presence of deuterium at very low levels, it has been used as a biological process tracer for years. Chemicals such as glucose are available where the hydrogen atoms are replaced with deuterium atoms. Magnetic resonance studies of the subject or samples taken from the subject can be used to determine where the deuterium “tagged” chemical went. In these cases, deuterium is considered to be non-toxic though the use is at extremely low levels.

    All of the words above are from what I have picked up in a few decades of work in nuclear and environmental sciences. There is a school of thought that holds that at some level of exposure between tracer studies and toxicity, deuterium can extend human life. Such supplements would not be cheap. The “fightaging.org” site is one that seems to have a somewhat enthusiastic approach but even the referred journals are publishing papers which indicate deuterium dosing at some low level would result in life extension (these papers are starting to show up in Google searches for deuterium and life extension).

    On the other hand, in humans it may just seem like you are living longer since all of your neurological processes are slightly slower. Sort of like life without coffee. Speaking of coffee, that sounds like a good closing. I’m off to get a cup.

    • ursiform says:

      Because a Deuteron is twice the mass of a proton the substitution has a more significant chemical effect than most isotopic substitutions. Spectroscopy, for example, is significantly different. Bond lengths are slightly different.

    • The fourth doorman of the apocalypse says:

      Very high prompt exposure to tritium gas and water is normally treated by aggressive hydration therapy. This used to be accomplished by alternating doses of beer, coffee, and glasses of water.

      “Get me a beer quick! I’ve been exposed to tritium gas”

    • Acres of Statuary says:

      ” Very high prompt exposure to tritium gas and water … (was formerly treated) by alternating doses of beer, coffee, and glasses of water.”

      Well, it’s good to know that if I ever get tritium poisoning I won’t have to change my drinking habits much!

      In fact you can combine two of the treatment stages into one, thus avoiding useless sober time:

      http://www.michiganbeerblog.net/2012/01/bottled-michigan-atwater-brewery.html

  2. gwern says:

    The deficiency experiments usually operate by giving the experimentals extremely purified food, right? I wonder how feasible this is for deuterium – it’s hard enough to extract heavy water, I can’t imagine there’s a lot of cheap de-deuterized water sitting around… (and that’s just the water! what do you do about about all the other hydrogen in the actual food for your mice or whatever?)

    • Deuterium water runs in excess of $1000 a liter (for the cheapest grade) in the US. Right now the price is controlled by limited demand, physics, and the involvement of the national government.

  3. Sean II says:

    Clearly you’ve found the long sought environmental driver of IQ differences. The left enders are either getting too much or too little, while the intellectual fat cats sit back avoiding or hoarding the stuff, respectively.

    What’s needed here is an equal access movement, or maybe an equal non-access movement, whichever.

  4. David Benson says:

    If deuterium water is separated by centrifuges, then de-deuterized water should an abundant and cheap byproduct of that process. (Not that anyone is saving it right now.) It seems to me that it would be easy to get ahold of some and repeat the algae-growing experiment.

  5. Patrick Boyle says:

    There was a big Hollywood movie starring Kirk Douglas about deuterium. It was called the ‘Heroes of Telemark’ . I just checked IMDB. Thirty commandos died in the events depicted in the film. All a waste because the heavy water had no effect on Nazi war efforts one way or the other – or at least I don’t think so. There is still some dispute as to how far along the Nazi were on their nuclear program. Some say Heisenberg sabotaged the whole thing from the inside. Other say that alone he just wasn’t enough. All the smart Jews had fled.

    I read Feynman’s stories about Los Alamos and I don’t remember Heavy Water being important. It looks to have been a false trail or a wild goose chase.

    • Murray Anderson says:

      The US program used a carbon moderator with unenriched uranium. Heavy water is a better moderator, allowing smaller reactors with such uranium, but you have to assure your supply, which the Germans failed to do at Telemark. The plant was blown up and the barge carrying the stored heavy water was sunk by Norwegian commandos. This was a sensible precaution, but the German program was going nowhere fast because of lack of organization and priorities.
      Israel obtained heavy water from Norway for its Dimona reactor.

  6. Hokie says:

    I’m guessing your interest was piqued with this: http://www.sciencedirect.com/science/article/pii/S0166432814004884. Unfortunately I’m not very familiar with isotope chemistry, we just label some compounds with deuterium so we get good readouts from nmr.

  7. Greying Wanderer says:

    Thinking aloud

    According to google Deuterium slows down cell division (hence making it good against cancer) (or is good against cancer so it might slow down cell division, one or the other) so might it slow aging?

    On the other hand if deuterium slows cell division maybe it’s bad for kids or at least bad for brain development of kids.

    If so naturally occurring heavy water (or heavier than average) might see a correlation between clusters of longevity and dumber people (or dumber kids but average people i.e. the brain develops the same just takes twice as long so the people are mentally adult much later).

    According to google you get naturally occurring deuterium in volcanic regions. Assuming it gets in the ground water that might mean centres of obsidian might have been / are also areas of heavier water so could be tested for any correlation with longevity & dumb people or longevity & dumb kids who turn into average people.

    http://www.obsidianlab.com/image_maps/image_maps.html

    http://en.wikipedia.org/wiki/Obsidian#Occurrence

    New Mexico seems to have quite a bit.

    (According to the interwebs the inner mountainous part of Sardinia has the most centenarians and is volcanic – dunno if they’re dumb or dumb when young though).

    • Greying Wanderer says:

      “i.e. the brain develops the same just takes twice as long so the people are mentally adult much later”

      although if that was true the skull might fuse before it was fully developed

      so

      skull shape and volcanic ground water?

    • Greying Wanderer says:

      Okinawa

  8. MawBTS says:

    Does “biological role” mean it’s needed for human life, or for carbon-based life in general?

    • gcochran9 says:

      With biological trace elements, absence effects range from lethality to slow growth and poor health. Most are needed by almost everything, others (like cadmium) apparently only in some species (diatoms, for Cd).

  9. Greying Wanderer says:

    Rambling now so apologies but

    if for the sake of argument deuterium regulated the rate of cell division such that heavy water was bad for kids (brain development) but good for adults after they’d had their kids (longevity and slowing down cancers) then that might lead to a bunch of testable predictions, for instance

    if heavy water made people dumber but longer lived I’d have thought the being dumber part would partially counter the longevity part but if so probably gender related i.e. the women might have above average life spans but the men more or less average (+longevity -dumbness) (as a lot of dumbness related non longevity would revolve around testosterone stuff like drink driving).

    On the other hand if seafood compensates for the dumbness aspect then you might predict this effect (if it existed) would be inversely proportional to distance from the coast so somewhere like Japan might get the benefit of the longevity without the dumbness because the dumbness was compensated for

    http://www.glgarcs.net/figurepage/fig_vol_distribution.html

    so is the lifespan of Japanese in Brazil a lot lower than in Japan?

    Also makes me wonder about the “Mediterranean diet”, Appalachia etc.

    #

    Might lead to hominids living in heavy water regions long enough to develop adaptations that sped up brain development in their kids to compensate.

    #

    Makes me wonder about a “slow drug” for STL spaceships.

  10. The fourth doorman of the apocalypse says:

    OT, but someone over at Vox Day speculates that if humans express sialic acid in their mucus they might also “express the the signaling lymphocyte activation molecule (SLAM),CD46, and nectin-4 in their mucus, people could be just as immune.”

    Wonder if that is possible?

  11. AppSocRes says:

    A bit OT, but one of the plot elements in Neil Stephenson’s Baroque Cycle was a fictional account of Isaac Newton dealing with “Solomonic Gold” while he was master of the English mint. This gold apparently contained an exceptionally high ratio of isotopes. But Newton could not know this. All he knew was that this oddly heavy gold was interfering with his attempts to stop counterfeiting. (The whole thing is fiction, of course, except for the historical fact that Newton was a highly effective manager of the mint who took ruthless pleasure in eradicating counterfeiting and counterfeiters.)

  12. melendwyr says:

    There’s an observation/joke that mathematicians keep trying to find useless math – something that can be appreciated for its abstract beauty alone – but everything they find ends up being put to use one way or another.

    I would be very surprised if, in the entire biological world, deuterium had no functional at all. Lots of toxic elements have turned out to have a use in some organisms, if only because they’re toxic. Sure, certain heavy metals tend to be ‘confused’ for healthy substances, but certain plants selectively take up and concentrate them because they’re a defense against predation.

    It might be most efficient to look for a use among bacteria, and other tiny organisms that exist in large numbers and can relatively easily be cultured in a low-deuterium environment. Worst case scenario, you could always see if you could evolve strains that made use of the isotopic differences.

  13. Greying Wanderer says:

    Kind of off-topic but related to water – still think there must be a valley somewhere with naturally de-deuterated and naturally heavier water to see if there’s any effects but in the meantime in water vapor at least it varies with latitude, heavier at the tropics, lighter the further north you go.

    http://onlinelibrary.wiley.com/doi/10.1029/2004GL019433/full

    http://onlinelibrary.wiley.com/store/10.1029/2004GL019433/asset/image_n/grl18036-fig-0003.png?v=1&t=i7e2ur93&s=22f694bd6a5582d76c875d8b6e0dfc92ca1081fc

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