5 ms·

I just read that rainwater around the world is unsafe to drink because of PFAS contamination. https://phys.org/news/2022-08-rainwater-unsafe-due-chemicals.html

I just read that rainwater around the world is unsafe to drink because of PFAS contamination. https://phys.org/news/2022-08-rainwater-unsafe-due-chemicals.html https://phys.org/news/2022-08-rainwater-unsafe-due-chemicals...

bilsbie 4y ago
Rainwater pretty much distills itself as it evaporates. I didn’t read the article but it seems like they’d new some new physics to get it into rain.
- philipkglass 4y ago
  The PFAS that show up in rain get there by also having a vapor pressure sufficient for atmospheric transport. They evaporate and condense with the rain. These chemicals aren't Teflon itself but other polyfluorinated molecules, used as intermediates in Teflon product production or for other purposes.
- deleted 4y ago
  [deleted]
- hombre_fatal 4y ago
  I just googled it. PFAS are simply emitted into the atmosphere and then brought back, rain precipitation being one method of "atmospheric deposition" (something to google). i.e. water doesn't need to evaporate with something in aerosol suspension for that thing to be found in precipitation.
Victerius 4y ago
.
- chinathrow 4y ago
  > I would be banned if I laid out the remainder of my thinking. Go ahead.
  - Aachen 4y ago
    I don't know what a bannable offense on HN would be, inciting violence perhaps? Wishing harm upon certain groups? Either way, I'm not sure we need to invite it if they already say it's over the line and not suitable. If we can have a civil discussion then obviously I'm with you that everyone should have their say... but that wouldn't elicit a ban.
    - NaturalPhallacy 4y ago
      Irritating dang is enough.
- pbhjpbhj 4y ago
  Throwaway accounts are a thing ...
- hammock 4y ago
  Can be purified. Activated charcoal filters are not the most efficient solution, but work reasonably well and can be easily built in an off-grid environment
  - johnchristopher 4y ago
    > In order to make activated charcoal with all its nooks and crannies, regular carbon sources are transformed in one of two ways: either physically or chemically. > In physical activation, wood, coal, or any regular carbon source is first heated up to 600 to 900 degrees Celsius (1000 to 1600 degrees Fahrenheit) in a chamber filled with inert gas. The inert gas ensures that the carbon doesn’t burn. Instead, as the carbon is heated, any impurities left on it are vaporized and removed, leaving nothing but pure carbon. > Next, the pure carbon is exposed to oxygen or steam baths at even higher temperatures. This causes the carbon to fracture and form the fractal shapes with their extremely large total surface area. > In chemical activation, raw carbon sources are mixed with an acid, base, or a salt. The mixture is then heated. Chemical activation takes less heat and less time to achieve the end result, which makes it the method of choice for large scale activation. Doesn't look "easily" to me but that's the first link google showed me (https://www.thinkcrucial.com/blogs/blog/how-activated-charcoal-filters-work https://www.thinkcrucial.com/blogs/blog/how-activated-charco...) What bothers me though is that our environment is changing so much and so fast that homo sapiens could not emerge tomorrow like they did first. No way a primate without culture or science is going to regularly scramble a charcoal filter to drink water.
    - hammock 4y ago
      Basic Steps Burn hardwood to make charcoal. Cool overnight. Powder the charcoal using a hammer or mortar and pestle. Add calcium chloride solution. Spread on a clean sheet or cheesecloth. Bake at 250 F for 30 minutes or until all moisture is entirely gone.
      - justnotworthit 4y ago
        According to a trial in nicaragua, from memory (google it), 25%-50% salt solution; soak the charcoal (which is crushed to the point of not filtering too much through whatever filtering mechanism you're going to use) for 24 hours; let dry in the sun (plenty of sun in their trial, i assume baking is the same). (Can't remember if they rinsed).
- TylerE 4y ago
  Life is unsafe. I suspect you would be at a much much much higher risk from not having ready access to medicine and doctors than PFAS.
  - throw8383833jj 4y ago
    Or at higher risk from having access to medicine and doctors. The overuse of medicine as the solution to everything is causing a lot of harm. A pill for every ill. In the US, it's not uncommon for people to be taking 7 different pills at once! I don't think people lived like this 100 years ago.
    - TylerE 4y ago
      People died young from totally treatable Illnesses 100 years ago. Being diabetic was basically a death sentence
    - qzw 4y ago
      100 years ago people sat in rotting whale carcasses to cure their ailments[0]. People have actually always taken weird crap for whatever ailed them because we’re pretty fragile creatures with many afflictions. I’ll gladly trade dying of simple cuts and strep throat for modern medicine, even if I have to take 7 different pills at once. [0] https://www.smithsonianmag.com/smart-news/prescription-rheumatism-used-be-sit-inside-rotting-whale-30-hours-180950335/ https://www.smithsonianmag.com/smart-news/prescription-rheum...
- throw8383833jj 4y ago
  why is this comment downvoted? I think it's a legitimate complaint about rainwater not being safe from PFAS.
drewcoo 4y ago
Made me wonder how much of it we're breathing. Especially in the fog if it's waterborne.
- randycupertino 4y ago
  Bay Area coastal fog has been found to contain high levels of mercury: https://news.ucsc.edu/2019/11/wilmers-mercury.html https://news.ucsc.edu/2019/11/wilmers-mercury.html > Mercury, a naturally occurring element, is released into the environment through a variety of natural processes and human activities, including mining and coal-fired power plants. "Mercury is a global pollutant," said Weiss-Penzias. "What's emitted in China can affect the United States just as much as what's emitted in the United States." > As atmospheric mercury rains down on oceans, it is converted by anaerobic bacteria in deep waters to methylmercury, the most toxic form of mercury. Upwelling brings some methylmercury to the surface, where it is released back into the atmosphere and carried by fog. At high concentrations, methylmercury can cause neurological damage, including memory loss and reduced motor coordination, and it can decrease the viability of offspring. > "Fog is a stabilizing medium for methylmercury," said Weiss-Penzias. "Fog drifts inland and rains down in microdroplets, collecting on vegetation and dripping to the ground, where the slow process of bioaccumulation begins."
majormajor 4y ago
Is there universal treatment for this in most countries or does this also imply that municipal water everywhere is equally "unsafe"? Some quick Googling suggests common britta filters don't remove it either, for instance. unsafe in scare quotes because the article says environmental levels have been steady for the past 20 years and we aren't all dead yet... and lots of animals of course drink rainwater more directly out of bodies of water. It's obviously not a good thing but I don't this means "we're doomed"... the article here cites a professor saying we just have to live with it, but it would be also interesting to see if anyone had leads on removal or any sort of mitigation/protection/neutralization schemes.
IshKebab 4y ago
> However, Cousins noted that PFAS levels in people have actually dropped "quite significantly in the last 20 years" and "ambient levels (of PFAS in the environment) have been the same for the past 20 years". > "What's changed is the guidelines. They've gone down millions of times since the early 2000s, because we've learned more about the toxicity of these substances."

bilsbie 4y ago

Rainwater pretty much distills itself as it evaporates. I didn’t read the article but it seems like they’d new some new physics to get it into rain.

philipkglass 4y ago
The PFAS that show up in rain get there by also having a vapor pressure sufficient for atmospheric transport. They evaporate and condense with the rain. These chemicals aren't Teflon itself but other polyfluorinated molecules, used as intermediates in Teflon product production or for other purposes.
deleted 4y ago
[deleted]
hombre_fatal 4y ago
I just googled it. PFAS are simply emitted into the atmosphere and then brought back, rain precipitation being one method of "atmospheric deposition" (something to google). i.e. water doesn't need to evaporate with something in aerosol suspension for that thing to be found in precipitation.

Victerius 4y ago

chinathrow 4y ago
> I would be banned if I laid out the remainder of my thinking. Go ahead.
- Aachen 4y ago
  I don't know what a bannable offense on HN would be, inciting violence perhaps? Wishing harm upon certain groups? Either way, I'm not sure we need to invite it if they already say it's over the line and not suitable. If we can have a civil discussion then obviously I'm with you that everyone should have their say... but that wouldn't elicit a ban.
  - NaturalPhallacy 4y ago
    Irritating dang is enough.
pbhjpbhj 4y ago
Throwaway accounts are a thing ...
hammock 4y ago
Can be purified. Activated charcoal filters are not the most efficient solution, but work reasonably well and can be easily built in an off-grid environment
- johnchristopher 4y ago
  > In order to make activated charcoal with all its nooks and crannies, regular carbon sources are transformed in one of two ways: either physically or chemically. > In physical activation, wood, coal, or any regular carbon source is first heated up to 600 to 900 degrees Celsius (1000 to 1600 degrees Fahrenheit) in a chamber filled with inert gas. The inert gas ensures that the carbon doesn’t burn. Instead, as the carbon is heated, any impurities left on it are vaporized and removed, leaving nothing but pure carbon. > Next, the pure carbon is exposed to oxygen or steam baths at even higher temperatures. This causes the carbon to fracture and form the fractal shapes with their extremely large total surface area. > In chemical activation, raw carbon sources are mixed with an acid, base, or a salt. The mixture is then heated. Chemical activation takes less heat and less time to achieve the end result, which makes it the method of choice for large scale activation. Doesn't look "easily" to me but that's the first link google showed me (https://www.thinkcrucial.com/blogs/blog/how-activated-charcoal-filters-work https://www.thinkcrucial.com/blogs/blog/how-activated-charco...) What bothers me though is that our environment is changing so much and so fast that homo sapiens could not emerge tomorrow like they did first. No way a primate without culture or science is going to regularly scramble a charcoal filter to drink water.
  - hammock 4y ago
    Basic Steps Burn hardwood to make charcoal. Cool overnight. Powder the charcoal using a hammer or mortar and pestle. Add calcium chloride solution. Spread on a clean sheet or cheesecloth. Bake at 250 F for 30 minutes or until all moisture is entirely gone.
    - justnotworthit 4y ago
      According to a trial in nicaragua, from memory (google it), 25%-50% salt solution; soak the charcoal (which is crushed to the point of not filtering too much through whatever filtering mechanism you're going to use) for 24 hours; let dry in the sun (plenty of sun in their trial, i assume baking is the same). (Can't remember if they rinsed).
TylerE 4y ago
Life is unsafe. I suspect you would be at a much much much higher risk from not having ready access to medicine and doctors than PFAS.
- throw8383833jj 4y ago
  Or at higher risk from having access to medicine and doctors. The overuse of medicine as the solution to everything is causing a lot of harm. A pill for every ill. In the US, it's not uncommon for people to be taking 7 different pills at once! I don't think people lived like this 100 years ago.
  - TylerE 4y ago
    People died young from totally treatable Illnesses 100 years ago. Being diabetic was basically a death sentence
  - qzw 4y ago
    100 years ago people sat in rotting whale carcasses to cure their ailments[0]. People have actually always taken weird crap for whatever ailed them because we’re pretty fragile creatures with many afflictions. I’ll gladly trade dying of simple cuts and strep throat for modern medicine, even if I have to take 7 different pills at once. [0] https://www.smithsonianmag.com/smart-news/prescription-rheumatism-used-be-sit-inside-rotting-whale-30-hours-180950335/ https://www.smithsonianmag.com/smart-news/prescription-rheum...
throw8383833jj 4y ago
why is this comment downvoted? I think it's a legitimate complaint about rainwater not being safe from PFAS.

drewcoo 4y ago

Made me wonder how much of it we're breathing. Especially in the fog if it's waterborne.

randycupertino 4y ago
Bay Area coastal fog has been found to contain high levels of mercury: https://news.ucsc.edu/2019/11/wilmers-mercury.html https://news.ucsc.edu/2019/11/wilmers-mercury.html > Mercury, a naturally occurring element, is released into the environment through a variety of natural processes and human activities, including mining and coal-fired power plants. "Mercury is a global pollutant," said Weiss-Penzias. "What's emitted in China can affect the United States just as much as what's emitted in the United States." > As atmospheric mercury rains down on oceans, it is converted by anaerobic bacteria in deep waters to methylmercury, the most toxic form of mercury. Upwelling brings some methylmercury to the surface, where it is released back into the atmosphere and carried by fog. At high concentrations, methylmercury can cause neurological damage, including memory loss and reduced motor coordination, and it can decrease the viability of offspring. > "Fog is a stabilizing medium for methylmercury," said Weiss-Penzias. "Fog drifts inland and rains down in microdroplets, collecting on vegetation and dripping to the ground, where the slow process of bioaccumulation begins."

majormajor 4y ago

Is there universal treatment for this in most countries or does this also imply that municipal water everywhere is equally "unsafe"? Some quick Googling suggests common britta filters don't remove it either, for instance. unsafe in scare quotes because the article says environmental levels have been steady for the past 20 years and we aren't all dead yet... and lots of animals of course drink rainwater more directly out of bodies of water. It's obviously not a good thing but I don't this means "we're doomed"... the article here cites a professor saying we just have to live with it, but it would be also interesting to see if anyone had leads on removal or any sort of mitigation/protection/neutralization schemes.

IshKebab 4y ago

> However, Cousins noted that PFAS levels in people have actually dropped "quite significantly in the last 20 years" and "ambient levels (of PFAS in the environment) have been the same for the past 20 years". > "What's changed is the guidelines. They've gone down millions of times since the early 2000s, because we've learned more about the toxicity of these substances."