6 ms·

Interesting. Two studies with pretty much conflicting conclusions about safety of copper for potable water. I imagine that there is a level (range) of exposur

Interesting. Two studies with pretty much conflicting conclusions about safety of copper for potable water. I imagine that there is a level (range) of exposure that is in the sweet spot between 'kills harmful microbes' and 'kills/harms humans who drink the water'.

maxxxxx 9y ago
One study is abut storing water in copper pots and the other is about copper in drinking water. Does storing water in pots automatically mean that the copper goes into the water and if yes, how high is the concentration?
- cmrx64 9y ago
  TFA looked at the copper concentration in the water after storage and it was below WHO guidelines for safe copper levels. Whether the WHO guidelines are sufficient or not is another question.
  - kleiba 9y ago
    The WHO guideline for copper is 2mg/l which is the same as in the German guidelines "Trinkwasserverordnung". The article linked by batter says right in the abstract: We found that the disease can even be caused by copper concentrations below the allowed concentration given by the German Guidelines for Drinking Water (Trinkwasserverordnung).
  - deleted 9y ago
    [deleted]
- thatcat 9y ago
  >Does storing water in pots mean that Cu goes into water It's not automatic, but depends on pH. Acidic conditions will be favorable to metals leaching into water. The paper cites an initial pH of 7.84, and final pH of 7.94 - so the pH increased slightly as a result of the copper entering the solution. This pH change correlated with 177 ppb Cu concentration in these pots after 16 hours. If initial pH was lower this concentration would see a logarithmic increase in relation the lower initial pH over the same time interval. "Since distilled water is slightly acidic (pH 6.7±0.05) which might enhance copper leaching, we have demonstrated the effect of copper pot in regular drinking-water"
  - std_throwaway 9y ago
    A quick google says: Drinking water in the US of A must have at least a pH of 6.5. They should have tested with that. I assume, the copper concentration would increase over 10-fold in that case versus the tested case.
- LgWoodenBadger 9y ago
  How is storing it in copper pots significantly different than "storing" it in the copper pipes prevalent in a majority of houses in the USA?
  - jessaustin 9y ago
    That's true for houses of a particular age and value. New stuff is all PEX, and has been for some time. Old enough houses would have been cast iron. Cheaper houses (mobile homes, for example) were all PVC for a long time. I had to dig up and repair a sewer pipe yesterday, and was somewhat surprised to find that it was made of clay tile.
    - icantdrive55 9y ago
      PEX is relatively new. There's still a lot of plumbers/HVAC guys who exclusively work with cooper, unless the owner wants PEX. How do I know? Contractor, and I have two rolls of Upunor on my garage, and still thinking (three years thinking) about doing my re-pipe in copper. Actually I have enough sticks of copper to do the job. Now--I just need the energy,mand motivation. Maybe today? (To anyone doing their own plumbing repairs. Do a bit at a time. Never just rip it all out.)
    - HillaryBriss 9y ago
      in Los Angeles county (and, I believe, LA City), clay pipe is still an approved material for sewer pipe laterals http://dpw.lacounty.gov/general/faq/index.cfm?Action=getAnswers&FaqID=IyNNMzMK http://dpw.lacounty.gov/general/faq/index.cfm?Action=getAnsw... http://library.amlegal.com/nxt/gateway.dll/California/lamc/municipalcode/chaptervipublicworksandproperty?f=templates$fn=default.htm$3.0$vid=amlegal:losangeles_ca_mc$anc=JD_64.17 http://library.amlegal.com/nxt/gateway.dll/California/lamc/m....
    - jessaustin 9y ago
      'icantdrive55 the thread is about water supply lines, not boilers or HVAC evaporator coils. I've dealt with a number of plumbers over the last several years, and not one wanted to use anything but PEX for supply lines. Actually a different preference would be a strike against any plumber I'd consider hiring for new work. Also you appear to be hellbanned.
ghvknvgvh 9y ago
Note that the authors of the paper being discussed are Indian. Literally any way of having potable water is better than what they do now.

maxxxxx 9y ago

One study is abut storing water in copper pots and the other is about copper in drinking water. Does storing water in pots automatically mean that the copper goes into the water and if yes, how high is the concentration?

cmrx64 9y ago
TFA looked at the copper concentration in the water after storage and it was below WHO guidelines for safe copper levels. Whether the WHO guidelines are sufficient or not is another question.
- kleiba 9y ago
  The WHO guideline for copper is 2mg/l which is the same as in the German guidelines "Trinkwasserverordnung". The article linked by batter says right in the abstract: We found that the disease can even be caused by copper concentrations below the allowed concentration given by the German Guidelines for Drinking Water (Trinkwasserverordnung).
- deleted 9y ago
  [deleted]
thatcat 9y ago
>Does storing water in pots mean that Cu goes into water It's not automatic, but depends on pH. Acidic conditions will be favorable to metals leaching into water. The paper cites an initial pH of 7.84, and final pH of 7.94 - so the pH increased slightly as a result of the copper entering the solution. This pH change correlated with 177 ppb Cu concentration in these pots after 16 hours. If initial pH was lower this concentration would see a logarithmic increase in relation the lower initial pH over the same time interval. "Since distilled water is slightly acidic (pH 6.7±0.05) which might enhance copper leaching, we have demonstrated the effect of copper pot in regular drinking-water"
- std_throwaway 9y ago
  A quick google says: Drinking water in the US of A must have at least a pH of 6.5. They should have tested with that. I assume, the copper concentration would increase over 10-fold in that case versus the tested case.
LgWoodenBadger 9y ago
How is storing it in copper pots significantly different than "storing" it in the copper pipes prevalent in a majority of houses in the USA?
- jessaustin 9y ago
  That's true for houses of a particular age and value. New stuff is all PEX, and has been for some time. Old enough houses would have been cast iron. Cheaper houses (mobile homes, for example) were all PVC for a long time. I had to dig up and repair a sewer pipe yesterday, and was somewhat surprised to find that it was made of clay tile.
  - icantdrive55 9y ago
    PEX is relatively new. There's still a lot of plumbers/HVAC guys who exclusively work with cooper, unless the owner wants PEX. How do I know? Contractor, and I have two rolls of Upunor on my garage, and still thinking (three years thinking) about doing my re-pipe in copper. Actually I have enough sticks of copper to do the job. Now--I just need the energy,mand motivation. Maybe today? (To anyone doing their own plumbing repairs. Do a bit at a time. Never just rip it all out.)
  - HillaryBriss 9y ago
    in Los Angeles county (and, I believe, LA City), clay pipe is still an approved material for sewer pipe laterals http://dpw.lacounty.gov/general/faq/index.cfm?Action=getAnswers&FaqID=IyNNMzMK http://dpw.lacounty.gov/general/faq/index.cfm?Action=getAnsw... http://library.amlegal.com/nxt/gateway.dll/California/lamc/municipalcode/chaptervipublicworksandproperty?f=templates$fn=default.htm$3.0$vid=amlegal:losangeles_ca_mc$anc=JD_64.17 http://library.amlegal.com/nxt/gateway.dll/California/lamc/m....
  - jessaustin 9y ago
    'icantdrive55 the thread is about water supply lines, not boilers or HVAC evaporator coils. I've dealt with a number of plumbers over the last several years, and not one wanted to use anything but PEX for supply lines. Actually a different preference would be a strike against any plumber I'd consider hiring for new work. Also you appear to be hellbanned.

ghvknvgvh 9y ago

Note that the authors of the paper being discussed are Indian. Literally any way of having potable water is better than what they do now.