snopes.com  

Go Back   snopes.com > Urban Legends > Science

Reply
 
Thread Tools Display Modes
  #1  
Old 27 August 2015, 01:36 AM
A Turtle Named Mack's Avatar
A Turtle Named Mack A Turtle Named Mack is offline
 
Join Date: 21 June 2007
Location: Marietta, GA
Posts: 21,445
Spit Take The Dangerously Clean Water Used To Make Your iPhone

FACT: Water can be too clean to drink—so clean that it’s actually not safe to drink. That’s the kind of claim about water that people scoff at—it seems ridiculous on the face of it. Water too clean to drink? Give me a break. It’s water. Cleaner is better. But this is one wild water story that’s true.

http://www.fastcompany.com/1750612/d...ke-your-iphone

Except it is not entirely true as stated. Someone quoted this claim to me at the gym today, and I too scoffed. I acknowledged that it would dilute your minerals, especially electrolytes, but the person I talked with claimed that it was unsafe to drink ANY ultrapure water. Well, as the article goes on to admit:
Quote:
It’s also why it’s not safe to drink. A single glass of UPW wouldn’t hurt you. But even that one glass of water would instantly start leeching valuable minerals back out of your body.
So basically, it dilutes the body's mineral content. Some of the commenters on this article and other threads about this claim that the UPW is so hungry for minerals to ionically bond to that it will pull sodium out of the blood and cacium out of the bones. I don;t see that quite happening, without drinking an awful lot of it. It would not reach the bones as UPWw. The stomach has lots of liquid with ionized content, such as hydrochloric acid and various salts. The UPW would quickly become as impure as any other water. Now unlike drinking regular water, the UPW carries NO minerals of its own, so the dilution is more intense, but even drinking regular water can cause water intoxication by diluting the mineral concentration the body needs. And with either one, regular or UPW, the amount you would have to drink to seriously dilute the body is a distastefully great amount. I just cannot see any way that this UPW can be as dangerous as the hype makes it sound. But I am open to further information.
Reply With Quote
  #2  
Old 27 August 2015, 02:03 AM
crocoduck_hunter's Avatar
crocoduck_hunter crocoduck_hunter is offline
 
Join Date: 27 May 2009
Location: Roseburg, OR
Posts: 11,331
Default

Water itself dilutes the electrolyte PPM in your blood, it doesn't leach it out. You'll still have the same amount of electrolytes, they're just spread through more water. But it's only really dangerous if your electrolyte level is already off, like if you've been sweating a lot due to intensive exercise; that's why marathon runners drink things like Gatorade- it allows them to rehydrate without altering their electrolyte levels. Even if it were really dangerous to drink pure H2O, eating something that's high in electrolytes would solve the issue.
Reply With Quote
  #3  
Old 27 August 2015, 02:32 AM
GenYus234's Avatar
GenYus234 GenYus234 is offline
 
Join Date: 02 August 2005
Location: Mesa, AZ
Posts: 24,363
Default

The LD50 for 18 megohm water (about as pure as you can get) is 90 mL for a rat. For a human that would be 7.3 L or about 1.8 gallons.
Reply With Quote
  #4  
Old 27 August 2015, 03:47 AM
ganzfeld's Avatar
ganzfeld ganzfeld is offline
 
Join Date: 05 September 2005
Location: Kyoto, Japan
Posts: 23,010
Icon103

All I really want to know is how many iPhones I can drink before it might start to make me sick. kthxbai
Reply With Quote
  #5  
Old 27 August 2015, 10:42 AM
Crius of CoH's Avatar
Crius of CoH Crius of CoH is offline
 
Join Date: 13 February 2006
Location: Paragon City (Cranston), RI
Posts: 1,595
Default

This is old mountaineering news - mountain lakes made from glacier water is (supposedly) so pure that drinking it in sufficient quantities begins to leech minerals from your body. Heard that back in the 70's, and my recollection is that it was old news then.

Also have been informed multiple times from multiple sources over my whole life that one should not drink distilled water for the same reason.
Reply With Quote
  #6  
Old 27 August 2015, 02:19 PM
Dr. Dave Dr. Dave is offline
 
Join Date: 28 June 2005
Location: Montgomery County, MD
Posts: 5,221
Default

If you drink a lot of even tap water and eat or drink nothing else your serum sodium will drop. If you drink a lot more, it can drop to dangerous levels. But it takes a lot. Examples: psychogenic polydipsia, some marathon runners.

ETA: 7 liters mentioned by GenYus234 counts a lot, even for the regular stuff.
Reply With Quote
  #7  
Old 27 August 2015, 06:38 PM
jimmy101_again jimmy101_again is offline
 
Join Date: 29 December 2005
Location: Greenwood, IN
Posts: 6,582
Default

The cite is a great example of Bad Science. The concentration of salts in human serum is about 10 grams per liter. Drinking (potable) water is typically less than 100 PPM, which is 0.1 grams per liter. So all potable water will leach salt(s) from the body and salt-free water really isn't all that much different than regular tap water in that regard. Taking GenYus234's numbers, the difference in LD50 (lethal dose, 50% death) for salt-free water versus tap water would be expected to be 1.80 versus 1.82 gallons. So, yes, salt free water is more "toxic" than regular tap water but the difference is absolutely irrelevant to life.
Reply With Quote
  #8  
Old 27 August 2015, 07:27 PM
UrbanLegends101 UrbanLegends101 is offline
 
Join Date: 24 November 2010
Location: Florida
Posts: 1,179
Default

Quote:
Originally Posted by Crius of CoH View Post

Also have been informed multiple times from multiple sources over my whole life that one should not drink distilled water for the same reason.
Guess I should have a major problem. We've used only distilled water for the last 9 years for our drinking water and cooking water.

For two years, we were in a location where the city water wasn't necessarily potable and while our water here in Kuwait generally is potable from the tap, the house water is stored in tanks on the roof. Since we had the distiller from the previous location, we just hooked it up when we moved to Kuwait.

Last edited by UrbanLegends101; 27 August 2015 at 07:33 PM.
Reply With Quote
  #9  
Old 28 August 2015, 12:27 AM
Crius of CoH's Avatar
Crius of CoH Crius of CoH is offline
 
Join Date: 13 February 2006
Location: Paragon City (Cranston), RI
Posts: 1,595
Default

Quote:
Originally Posted by UrbanLegends101 View Post
Guess I should have a major problem. We've used only distilled water for the last 9 years for our drinking water and cooking water.

For two years, we were in a location where the city water wasn't necessarily potable and while our water here in Kuwait generally is potable from the tap, the house water is stored in tanks on the roof. Since we had the distiller from the previous location, we just hooked it up when we moved to Kuwait.
We may be talking different things; I'm referring to the commercially-available-in-gallon-jugs (in the US at least) distilled water that is probably best known as what you're supposed to use in your steam iron, to prevent mineral build-up. It's "super pure" water, like what the OP is discussing. Distilling water to make it potable is, I think, another animal entirely. Or not, I don't know. I'll leave it to someone with an erg or more energy than I have to do the minimal amount of googling necessary to confirm things one way or the other.
Reply With Quote
  #10  
Old 28 August 2015, 06:30 AM
Troberg Troberg is offline
 
 
Join Date: 04 November 2005
Location: Borlänge, Sweden
Posts: 11,580
Default

Quote:
Originally Posted by GenYus234 View Post
The LD50 for 18 megohm water (about as pure as you can get) is 90 mL for a rat. For a human that would be 7.3 L or about 1.8 gallons.
I'm not surprised. A rat drinks very little, maybe 10 ml per day, or 20 if it's extremely thirsty and only gets dry pellets to eat. I doubt their stomach even can hold 90 ml. In other words, I wouldn't be surprised if LD50 for tap water would be pretty much the same.
Reply With Quote
  #11  
Old 28 August 2015, 10:18 AM
UrbanLegends101 UrbanLegends101 is offline
 
Join Date: 24 November 2010
Location: Florida
Posts: 1,179
Default

Understand.

The process is the same, although for ultrapure water, it is distilled more than once, so there residual contaminants from the first distillation process equipment are removed by the next stage and then the next stage.

Generally, the purity of the water can be determined by resistance measurements, the higher the resistance the purer the water. For potable water, it doesn't have to been that pure, just pure enough that we aren't ingesting harmful contaminants. For some types of contaminants, however, even distilling water isn't foolproof, especially if the water contaminants evaporate at lower temperatures than the boiling point of water, and in these cases, the first part of the distilled water in a batch system is discarded.


For certain cooling purposes, where we use distilled water in the cooling loops, the purity of the water determines how much electrical leakage current we have in the system. For those purposes, one would want to keep the water purity high enough for insulation purposes (a water column across insulators, as an example), keeping the leakage currents as low as reasonable, but not that the water purity is so high, it starts to leach out the metals used in the equipment. It is a balance.

We could use deionized water for the same purposes, but distillers are cheaper and much easier to feed and maintain.

Bear in mind that with ultrapure water, it takes very little common table salt, as an example, to reduce the purity back down to relatively low levels of resistance.
Reply With Quote
  #12  
Old 29 August 2015, 04:55 PM
jimmy101_again jimmy101_again is offline
 
Join Date: 29 December 2005
Location: Greenwood, IN
Posts: 6,582
Default

Quote:
Originally Posted by UrbanLegends101 View Post
Generally, the purity of the water can be determined by resistance measurements, the higher the resistance the purer the water. For potable water, it doesn't have to been that pure, just pure enough that we aren't ingesting harmful contaminants. For some types of contaminants, however, even distilling water isn't foolproof, especially if the water contaminants evaporate at lower temperatures than the boiling point of water, and in these cases, the first part of the distilled water in a batch system is discarded.
Purification of water generally has to consider two types of contaminants; salts and organics. Salts are generally what is measured by resistance since salt water is more electrically conductive than is distilled water. "Salts" include any ionic compound like calcium carbonate, and not just sodium chloride (table salt). Distillation is generally very effective at removing salts.

The resistance of water is not sensitive to organic contaminants. Gasoline tainted water will have the same resistance as uncontaminated water. Distillation is usually pretty good at removing organics though there is a small set of organic compounds that distillation wont remove no matter what is done (a notable one being ethanol). Other compounds can be removed though sometime it does require attention to details like discarding the first part of the distilled water.

"De-ionization" and water softening generally replaces one salt with another, for example replacing calcium ions with sodium ions. In some cases "de-ionization" can replace salts with either acid (H+) or base (OH-) and hence remove the salt (nearly) completely, though the pH of the resulting water may be far from neutral. Usually de-ionization gives water with similar electrical conductivity as the original water sample.

Organic filters (like activated charcoal) can remove many organic contaminants though how well they work varies pretty widely across the range of common organic contaminants.

The observation that in some industrial uses water can be "too pure" is interesting. Very low salt water can leach metal out of pipes (like UO said). I believe that is called "hungry water" and in some cases a small amount of salts might be reintroduced into the water to reduce the corrosice nature of highly purified water. (IIRC the primary cooling loop of nuclear reactors can have long term corrosion problems if the water is too pure.)

In biology it is sometimes the case that it isn't possible to remove all the salts from water. For example, as a practical matter it is pretty much impossible to remove all the iron from a water sample. Distillation gets the iron out of the water but there is enough iron bound to the surface of the final container to recontaminate the water. Even repeated washing of the final container with distilled water wont lower the level of iron contamination to zero. Many biological processes (including many common biological decay processes) critically depend on iron (and a few other metals) and to study those processes biologist go to great lengths, like triple-distilling the water and flushing the final water container with many times its volume of "clean" water before filling with "clean" water, to remove the iron salts. Even then, and even with extremely low levels of metal contamination, it is still often possible to detect metal catalysis of several biological processes.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Trees Make Sounds When They're Running Out Of Water, Lab Experiments Suggest TallGeekyGirl Techno-Babble 3 02 May 2013 06:42 PM
Should you be “Eating Clean”? Nick Theodorakis Snopes Spotting 2 02 February 2013 04:28 PM
Clean Windows snopes Glurge Gallery 6 02 August 2008 02:11 PM
Let's clean up the Internet snopes Snopes Spotting 0 23 January 2008 04:29 AM


All times are GMT. The time now is 07:15 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.