Sciencemadness Discussion Board

Deuterium toxicity

Pyrovus - 13-10-2003 at 23:29

Does anyone know exactly how toxic deuterium is (like would it be any good as a poison, not that I'm planning to do anything like that with it - I find it morally objectionable - it's such a waste, when it could be used to make hydrogen bombs.)

BromicAcid - 14-10-2003 at 15:45

Did you mean heavy water? The toxicity of deuterium is negligible due to it not being readily absorbed by the human body. Heavy water is present in normal water to a concentration of one part in 6500 so if it was incredibly hazardous we'd have problems, the water in our body cycles so it would not be a commutative poison.

deuterium rumor.. for what its worth

Mr. Wizard - 14-10-2003 at 18:57

I read somewhere that ingestion of deuterium could cause dizziness, which an author speculated was due to the heaviness of the heavy water (D2O) in the inner ear. I have no source to back it up but maybe you can search it out?

inkognito - 14-10-2003 at 22:18

how is deuterium made ?

inkognito - 15-10-2003 at 01:24

ah , i found my answer in some chemistry books .
--------------------------

Please edit your posts instead of double posting.

[Edited on 15-10-2003 by vulture]

Theoretic - 17-10-2003 at 04:49

If lab animals are given D2O instead of H2O, they die, because, I think, deuterium-element bonds are stronger than protium-element bonds (that means that chemical processes are slowed down). :)

blip - 17-10-2003 at 15:54

I thought that deuterium oxide had detrimental effects because its slightly better hydrogen bonding than water messes up the intricate process of protein folding... but I may be wrong.

D2O and toxicity

chemoleo - 29-10-2003 at 08:00

here comes the biochemist :P
Deuterium is not toxic, at least in small amounts. In fact, we can grow bacteria in D2O, rather than H2O, but they grow at about half the normal growth rate.
If you feed a human with D20 (in food, drink), he would eventually die, however. This would be a very expensive way to kill someone though, as 1/2 a litre costs about 600 Pounds (400 Euros, 450 $), and you'd need quite a few litres to replace the majority of of H with D.
Mice can actually sense the difference between D2O and H2O, so they won't drink the former. However, they recognise it based on it's physical properties rather than the chemistry, i.e. mice refuse D2O because it has a slightly higher viscosity & density.
The reason why higher organisms (such as humans) die from D2O in high doses is that the diffusion rate of D2O (which is a function of molecular size, shape and density) or rather D3O+ accross the mitochondrial membranes is slower. THis of course would include any other processes within the cell where diffusion is necessary for proper functioning of a system, such as protein synthesis in the cytoplasm.
So, you can imagine, if key energy conversion systems are running slow, while others are running at the normal speed, then the whole intricate balance is disturbed... and humans are far too complicated systems to tolerate this, they can't just grow at half the speed as bacteria can...

Edit: By the way, D2O is obtained by fractional distillation of natural H2O, as there are traces in it.... this is based on the higher boiling point of D2O!


[Edited on 30-10-2003 by chemoleo]

unionised - 2-11-2003 at 03:40

The only toxicity data I have on heavy water says it is toxic to mice (when they drink it) at levels of 3360 g/K (yes, more than 3 imes their bodyweight). At these levels it gives rise to reproductive problems in pregnant mice.
By comparison, ethyl alcohol gives rise to toxicity at 320mg/Kg (again, orally in mice).
Both of these must have been chronic studies and it's not striclty fair to compare them, but it does illustrate the problems you would have poisoning someone with D2O.

vulture - 2-11-2003 at 08:39

You can "make" water with higher D2O concentration by simply electrolysing water. Because of it's larger mass, D2O will react much more slowly and accumulate in the vessel.

You simply electrolysi until you have 1/5 of your starting amount left, add new water and so and so on.

Final word

jubrail - 4-11-2003 at 20:15

In animal physiology work, D2O is used often. Deuterium is not D2O, it is the D in it. It is definitely not that toxi. Just today I brought a rat's D2O level up to .805% of total plasma (not .805% of blood, just plasma - so that's higher as a BDC (blood-deuterium concentration), as the rat's hematocrit (red blood cell count was 52-53%). That means that D2O accounted for 1.5 to 2 out of every 100 water molecules in her blood.

The rat had absolutely no problem tolerating it, though rats are much more resilient than humans, and less complicated as chemoleo pointed out. If you are looking for a good poison, that is easy to obtain and isn't too suspicious as per law or too detectable, I would highly suggest bitter almond oil (benzaldehyde with a small, but adequate touch of prussic acid, aka cyanide) - strong but appetizing smell.

Please don't poison anyone, though.

chemoleo - 5-11-2003 at 17:10

sure, but 1 or 2 % is not much, humans could probably tolerate it too. The point is that D2O is actually not just in the blood, but rather *replaces* existing H in carbohydrates, proteins (most importantly), DNA, fats and RNA - *everywhere*. For this I guess you need a very long administration of D2O, as I seem to remember that a human replaces its entire body mass with so-to-speak fresh atoms every seven years or so, meaning that you'd have to feed a human D2O seven years long (including deuterated food) to make sure that every H is replaced with D. Surely though that poor individual would day way before that! And this would be due to the altered energy processes going on in the mitochondria...

[Edited on 6-11-2003 by chemoleo]

PHILOU Zrealone - 24-5-2004 at 16:48

To make D2O one of the ways is to decompose water H2O, HDO and D2O into H2, HD, D2 and O2 via electrolyse...then to allow the H2, HD, D2 to go through chromatography collumn...active carbon...Owing to the high difference of physical properties separation is easier...
D2 = 4g/mole
HD = 3g/mole
H2 = 2g/mole
This implies that at the same temperature..H2 migrates two times faster than D2 and 1,5 faster than HD...not counting of course with the difference of boiling points.

:cool::cool::cool::cool:

D2O ingestion = death??

oxydiser - 10-12-2004 at 09:17

I was in a prelab the other day for this NMR unit required in the third year of my degree *yaaawn* and the lab demonstrator said that the ingestion of ~20mL of D2O (deuterated water) was enough to kill you. Is he right or talking some serious bullshit??
By what mechanism could D2O possibly have this supposed toxicity? The only thing I can think of is that the D2O disrupts the action/kinetics of some crucial ion channel...any thoughts?

Oxydiser, the search function does prove useful on occasion :) Merged with existing thread. Chemoleo

[Edited on 10-12-2004 by chemoleo]

neutrino - 10-12-2004 at 16:37

Are you sure that he wasn’t just referring to a solution containing D<sub>2</sub>O?

Quote:
From Here
High concentrations in the body can affect biochemical processes. Ingestion of large amounts impairs kidney function, CNS operation. Chemical presents no hazard unless significant quantities are ingested.