The only way I can think of to win the argument is to use the Socrates technique and let them convince themselves.
Start by just asking for a ground rule or two: how much water and how pure? Just to get a feel for how pure is necessary, ask them how much, say, orange juice you’d need to mix with a cup (or whatever amount is deadly) of absolutely pure water to make it safe. Get them to commit to an actual amount (half a tablespoon? less?) OK now, how much of some other liquid, say, saliva, would you need to mix in to make it safe?
At this point, they should see the folly of their ways. You may have to ask why it’s different if you mix the saliva in the cup than if you mix it in your mouth and stomach.
This is the composition of normal urine:
Substance
Water 1.4 L/day
Urea 1820 mg/100mL
Uric acid 42 mg/100mL
Creatinine 196 mg/100mL
Sodium ion 128 mEq/L
Potassium ion 60 mEq/L
Chloride ion 134 mEq/L
Bicarbonate ion 14 mEq/L
pH 4.5 to 8.0
The only way for water, pure or otherwise, to strip the body of essential nutrients is to excrete them from the body as urine, tears, or sweat.
This is the composition of normal urine:
Substance
Water 1.4 L/day
Urea 1820 mg/100mL
Uric acid 42 mg/100mL
Creatinine 196 mg/100mL
Sodium ion 128 mEq/L
Potassium ion 60 mEq/L
Chloride ion 134 mEq/L
Bicarbonate ion 14 mEq/L
pH 4.5 to 8.0
About the only important nutrient here that you don’t get plenty of in normal food is potassium. Now, can excreting potassium at the rate of 60 mEq/L for 1.4 l/day seriously deplete the body’s potasssium supply? A milliequivalent of potassium weighs 0.039 grams, so 60 mEq/L X 1.6 L/day = 3.29 grams of potassium.
According to this site, the RDA for potassium is 3.5 grams, so we seem to be on the right track here.
Is there a significant difference between the potassium content of “pure” water and “normal” water? This site says that the normal potassium content of bottled water is less than 5 mg/l. So, if you drink 2 liters a day of bottled water compared to “pure” water you will accumulate a potassium deficit of 10 mg, approximately 0.3% of your RDA for this mineral. If you’re that close to the edge, you’ve got more problems than potassium deficiency.
Sorry about the double post, I am, in many respects, a clumsy oaf.
I cannot say exactly what the man meant by “pure water”. I thought someone here might have a better idea than me, but I know he wasn’t describing regular distilled water. Perhaps it was the pure water mentioned in an earlier post that was used to clean microchips and semiconductors.
I’m not saying the stuff burned holes through the floor like the creatures blood in “Alien”, just that it was a super efficient cleaner and that continued exposure to it would cause skin irritation and was not something you wanted to get splashed in your eyes, so people handling it wore gloves and googles for protection.
Maybe it wasn’t that harmful to drink, probably not as corrosive as stomach acid, but it didn’t sound like anything I would want to swallow on a bet.
18 megohm water is good for cleaning things, and the near absence of dissolved metal ions does make it better at leaching oils and such from your skin. If wallow in it all day, it will give you drier skin than regular old tap water.
It’s probably not good to wash your hair with it either, as it’ll strip the carbonates, sulfates and metal ions that normally keep your mop from going all frizzy and wild.
What it comes down too is really clean water is cleaner than you are and your skin, hair etc. is evolved to perform optimally when it is slightly dirty. There’s nothing particularly inimical about really pure water, however if you get your bits too clean, they won’t like it.
“Ice cream, Mandrake! Childrens’ ice cream!”
Stranger
I agree with a couple of things from that cite. One, I had not considered the effect of cooking food in deionized water, mainly because the OP had only specified drinkng water.
Two, I had neglected the corrosive effect on pipes. Unfortunately for the premise of the OP, you can’t have it both ways. Either drinking pure water is unhealthy because it is too pure, or it is unhealthy because it has absorbed contaminants from metal pipes, but it can’t be both.
Yes, deionized water should not be run through metal pipes, but nothing in the OP said that it would be. The question was, is
It is not.
Hey,you know, you can get a serious burn from a flashlight battery if it’s sitting on a hot stove when you pick it up. That doesn’t make a flashlight battery dangerous.
Lots of people have been reiterating that highly pure water will somehow strip things from either your body or from surfaces. This was also the central point of that alarmist health-nut article cited somewhere closer to the beginning of this thread.
However, the fact is that the concentration of a particular ion or substance is rather independent of the concentration of another. That is, pure water with NaCl or carbonate will leech all other minerals just as well as if it was entirely pure. Unless your water contains all minerals, it will reduce the concentrations in your body or on your skin of all the ones it does not have just as well as if it was pure entirely!
Second, some people do not realize that the distinction between “pure” water and “clean” water is not really that great. You’re not comparing pure water to mineral water! Unless your water has unusually high concentrations, it’ll leech things at pretty much the same amount as if it were pure of the highest grade.
So for all those who’ve said that drinking distilled water for a long time will rob you of sodium, potassium, and etc: Unless you drink salty, potassium-enriched water, it’ll happen regardless!
That’s only true for Ideal solutions. Mixed ions in water do not an ideal solution make.
In the real world, pH, Ionic strength and the dielectric constant, chaotropic agents such as magnesium or sodium ions, anti-chaotropes such as ammonium, or acetate, dissolved solvents, detergents and etc. all affect the ability of water to leech minerals, fats, proteins etc.
The various effects are not interchangeable or simply additive.
Stranger, some of the purest water one can get can be found in the condensate systems of a well-running steam plant. I worked on one for years. Our system was so tight we were constantly over-producing water for our ship. Our condensate system water regularly tested at less than 0.1 ppb O[sub]2[/sub] (Measuring dissolved oxygen in water is a relatively easy way to verify how much exposure to air a given sample of water may have had. To get those kinds of numbers, you can be sure we had a very tight condensation system.), with resistance measured in hundreds of kilo-ohms. The pH was usually on the order of 8.5, and that was accomplished by ammonia dissolved in solution.
In spite of all this, I’d never, ever been harmed by getting condensate water on my hands, shirts, pants, or feet. (And I’d have to spill a lot of it getting a good dissolved oxygen sample.) I really do think that this guy was just talking up something.
On this same ship, we added a very little bleach to our drinking water - but the reasons for that were two-fold: since we distilled our potable and DI water from sea water under a vacuum we couldn’t guarantee we’d cooked all the swimmies; and if one’s drinking water is too pure, so I was told, it could lead to problems with the runs.
This has got to be the archetype for SDMB overanswered questions. It should be used to show the masses what happens when you get a bunch of eggheads trying to answer a simple question, running around in circles, citing research, quoting data and throwing out all sorts of formulas and vocabulary, impressing themselves with terms and whatnot. It could be the “poster child” for what’s wrong with science - all scales and no music.
Guy says his girlfriend heard that drinking pure water could be fatal. Asks, could this be true? Instead of saying - Nah, don’t know what she could be thinking, the bbs goes crazy, starts speculating. From the barely possible to the outlandish. Well, if she drank only purified water for several years and ate nothing else… Well, if she were to simulate the structure of a hollow tube…well, if she were in nuclear medicine… Nice, and typical of the bbs to toss out wild notions, just for thought, but come on, now. Somebody’s got to bring this back to ground zero. Dude, the answer is no - drinking pure water isn’t fatal.
Jesus, what crawled up your ass and died?
“I can no longer sit back and allow Communist infiltration, Communist indoctrination, Communist subversion and the international Communist conspiracy to sap and impurify all of our precious bodily fluids.”
Stranger
But what if, what if…no. Oh yeah, what if she’s drinking pure deionized water … on a treadmill … when she’s hungry, angry and…damn. What was that last condition?
She’s reciting the three words ending with -gry, naturally.
That the water be 99.9999999… percent pure.
You ever see a Commie drink a glass of water, Stranger? :dubious:
And this has to be one of the silliest and least useful posts I’ve seen in GQ for some time.
Heaven forfend that we cite research, quote data, bring to bear formulas, or use technical terms! Oh the shame of it! Of course we do it just to impress ourselves, not because it has something to do with the question!
While the premise as stated is foolish, there is no reason not to examine and discuss why it is foolish. And the discussion has brought to light some rather interesting information, in particular that cited by Brain Wreck. I’ve certainly learned something from this thread. Even the most foolish propositions can turn out to have interesting aspects.
Someone asks if pure water is fatal and you don’t have the slightest idea why they’d ask something so ridiculous? It makes sense to try to figure it out. It turns out that she’s not the only person in the world who has this idea, and it turns out there are some subtle and interesting problems presented by the use of highly pure water for drinking and cooking, which have been outlined in a paper by the World Health Organization entitled “Health risks from drinking demineralized water”, which I’ve cited here multiple times.
One could say that your simplistic post is wrong with the general public… never try to understand anything, after all, if something can’t be understood with foggy recollections from high-school science class, then it couldn’t possibly be important. :rolleyes: