What makes water safe/unsafe to drink?

[decs]

i'm investigating how the molecular construction of water makes it safe for us to drink, what components would make it unsafe or 'less safe', and how i could test for these things.

Cheers,

 

[gravenewworld]

bacteria and heavy metals aren't good for drinking water.

 

[dx/dy=?]

Straight up,

Heavy metals, and heavy metal oxides are the worst.
Anything over 1-2% is toxic i think.

Bacteria and Viruses are up there,

Also, Acid Mine Water from mine drainage into Aquifers is really bad.

As for testing, distilling a water sample, and testing the precipatates accordingly is a laboursome way.
You could possibly use mass-spectroscopy.

 

[quetzalcoatl9]

we trade off the dangers of bacteria and viruses for other harmful (potentially carcinogenic) compounds such as chloramines and halogens.

 

[dx/dy=?]

almost any inorganic chemical is toxic in adequite amounts in drinking water.

 

[Moonbear]

We had a similar discussion in Biology a while back regarding drinking water safety, but not with any emphasis on detection of contaminants. You might want to refer back to that discussion for additional information on water treatment and issues regarding compounds formed during that treatment.

https://www.physicsforums.com/showthread.php?t=41740

 

[dx/dy=?]

Interesting thread.

 

[Edgardo]

Hello decs,

I've read about a student who died of drinking too much water,
he suffered from "hyponatremia":
http://www.accessexcellence.org/HHQ/qow/qow04/qow050314.html

Here another case:
http://www.washingtonpost.com/wp-dyn/content/article/2005/08/10/AR2005081001460.html
"Hyponatremia, an abnormally low salt concentration in the blood, occurs when a person loses a large amount of sodium or consumes a large amount of water. Hyponatremia in athletes is almost always caused by drinking too much water.

As the blood becomes increasingly diluted, water moves out of the bloodstream and into cells, which swell. The swelling of the brain is responsible for the symptoms of severe hyponatremia -- nausea, confusion, seizures and coma. If pressure inside the skull increases enough, the base of the brain is squeezed downward through where connects it to the spinal cord, causing death."

 

[dx/dy=?]

Ouch...