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The dose makes the poison here. How much lead is permissible before it’s bad? The answer is, very very very little. In comparison, you get copper contaminatio

The dose makes the poison here. How much lead is permissible before it’s bad? The answer is, very very very little. In comparison, you get copper contamination from copper pipes (especially if the water is too acidic), however the body handles a little copper just fine. It doesn’t build up in the body unlike lead. Then you’re left with plastics: PEX or PVC. As of yet, there’s some potential concerns with microplastics in general… but that is from all the tiny plastic particles found everywhere, not solid pieces of pipe. And there hasn’t really be any evidence that it causes any specific known issue. If it was some giant problem (like lead in drinking water!) then the magnitude of effect would be much more obvious.

mystified5016 2y ago
Yeah, the 'safe' level of lead is essentially zero. I think on the order of nanograms per liter. Common wisdom is "there is no safe level of lead".
- Kirby64 2y ago
  Sure, agreed. I’m just pointing out that the GP quibbles “what about microplastics” without comparing the known levels of lead (ie even extremely small amounts) that are unsafe. And it’s pretty obvious that high levels of lead lead to developmental issues. The same cannot currently be said of microplastics.
ars 2y ago
The underground feeder to your house is likely to be HDPE actually - which is chemically similar to PEX. Both are made from Polyethylene, which is the exact same stuff oil (including food), gas, wax, natural gas, etc is made off. i.e. you body handles that all the time.
- sebastiennight 2y ago
  Wait... when is the last time you've drank: - polyethylene oil? - gas? - natural gas? - wax (I'm assuming candle wax)? I understand you don't mean "drink" when you say our body "handles" it, but you do realize we don't make food from PET, nor do we usually "handle" gas and natural gas in any form of direct contact?* * with the fun exception of a brief craze in my high school years where people would mix hard alcohol with gasoline to make cocktails "stronger". That's another story though
  - ars 2y ago
    I'm not claiming you will get nutrition from it, I'm saying these thing are not toxic to the body because it has the necessary biological mechanisms to handle it. It's the same way that, even though you shouldn't drink it, acetone is barely toxic, because your body knows how to process it. I should remind you that there are other plastics, but polyethylene is not one of the toxic ones. (Gas, as in gasoline, has benzene which is a different category. Note also that many plastics have plasticizers which are also a different category, although polyethylene rarely has any, it's possible that it could.)
garaetjjte 2y ago
>If it was some giant problem (like lead in drinking water!) then the magnitude of effect would be much more obvious. If that was such an obvious problem, they wouldn't have put the lead pipes in the first place...
- Kirby64 2y ago
  Science had evolved massively in 50 years. We used to put lead in gasoline too.
  - notjulianjaynes 2y ago
    We've known lead was harmful for nearly 2,000 years though [1]. Compare that timeline to compounds created, widely used, and then discovered to be harmful in the past 50 years. I am not advocating for lead or copper soldered water pipes, but I am conservatively skeptical about PVC being totally safe for the same timeline existing lead pipes have been in use. In July the EPA proposed raising the priority rating of vinyl chloride on its toxic substances list. It doesn't seem implausible to me that in 50 years we'll be taking about PVC pipes the same way were talking about lead pipes today. I am not claiming that PVC water pipes are dangerous just that I am skeptical there is enough historical data to claim they are totally risk free. I am not a scientist or expert on this subject 1.https://penelope.uchicago.edu/encyclopaedia_romana/wine/leadpoisoning.html https://penelope.uchicago.edu/encyclopaedia_romana/wine/lead... Edit: added source
    - Kirby64 2y ago
      People knew lead was harmful in large quantities, sure, but the science around just how bad lead is and how little can cause damage I would say was not known. Regarding PVC: It already is not used in almost any new construction for water supply lines, at least in the US. It's used for drains, but the leeching concern isn't really an issue for drain pipes. No water pressure, and no continuous immersion typically. Issues about BPA/vinyl compounds are As per PEX, I can't say for certain that it's 100% risk free, but overall there is increased scrutiny on drinking water and contaminates and PEX right now seems to be the best choice.

mystified5016 2y ago

Yeah, the 'safe' level of lead is essentially zero. I think on the order of nanograms per liter. Common wisdom is "there is no safe level of lead".

Kirby64 2y ago
Sure, agreed. I’m just pointing out that the GP quibbles “what about microplastics” without comparing the known levels of lead (ie even extremely small amounts) that are unsafe. And it’s pretty obvious that high levels of lead lead to developmental issues. The same cannot currently be said of microplastics.

ars 2y ago

The underground feeder to your house is likely to be HDPE actually - which is chemically similar to PEX. Both are made from Polyethylene, which is the exact same stuff oil (including food), gas, wax, natural gas, etc is made off. i.e. you body handles that all the time.

sebastiennight 2y ago
Wait... when is the last time you've drank: - polyethylene oil? - gas? - natural gas? - wax (I'm assuming candle wax)? I understand you don't mean "drink" when you say our body "handles" it, but you do realize we don't make food from PET, nor do we usually "handle" gas and natural gas in any form of direct contact?* * with the fun exception of a brief craze in my high school years where people would mix hard alcohol with gasoline to make cocktails "stronger". That's another story though
- ars 2y ago
  I'm not claiming you will get nutrition from it, I'm saying these thing are not toxic to the body because it has the necessary biological mechanisms to handle it. It's the same way that, even though you shouldn't drink it, acetone is barely toxic, because your body knows how to process it. I should remind you that there are other plastics, but polyethylene is not one of the toxic ones. (Gas, as in gasoline, has benzene which is a different category. Note also that many plastics have plasticizers which are also a different category, although polyethylene rarely has any, it's possible that it could.)

garaetjjte 2y ago

>If it was some giant problem (like lead in drinking water!) then the magnitude of effect would be much more obvious. If that was such an obvious problem, they wouldn't have put the lead pipes in the first place...

Kirby64 2y ago
Science had evolved massively in 50 years. We used to put lead in gasoline too.
- notjulianjaynes 2y ago
  We've known lead was harmful for nearly 2,000 years though [1]. Compare that timeline to compounds created, widely used, and then discovered to be harmful in the past 50 years. I am not advocating for lead or copper soldered water pipes, but I am conservatively skeptical about PVC being totally safe for the same timeline existing lead pipes have been in use. In July the EPA proposed raising the priority rating of vinyl chloride on its toxic substances list. It doesn't seem implausible to me that in 50 years we'll be taking about PVC pipes the same way were talking about lead pipes today. I am not claiming that PVC water pipes are dangerous just that I am skeptical there is enough historical data to claim they are totally risk free. I am not a scientist or expert on this subject 1.https://penelope.uchicago.edu/encyclopaedia_romana/wine/leadpoisoning.html https://penelope.uchicago.edu/encyclopaedia_romana/wine/lead... Edit: added source
  - Kirby64 2y ago
    People knew lead was harmful in large quantities, sure, but the science around just how bad lead is and how little can cause damage I would say was not known. Regarding PVC: It already is not used in almost any new construction for water supply lines, at least in the US. It's used for drains, but the leeching concern isn't really an issue for drain pipes. No water pressure, and no continuous immersion typically. Issues about BPA/vinyl compounds are As per PEX, I can't say for certain that it's 100% risk free, but overall there is increased scrutiny on drinking water and contaminates and PEX right now seems to be the best choice.