Environment: Plastics in rainfall (PFOA and PFAS)

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In summary, the article says that the guideline for PFOA in drinking water has progressively decreased over the last 22 years, and that no rainwater in the world is safe to drink.
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TL;DR Summary
Study points to rainwater being unsafe due to plastics.
Just came upon this item.
Is it something to worry about - of course it is - but seriously, we can't have fun in the rain anymore.


“Based on the latest U.S. guidelines for PFOA in drinking water, rainwater everywhere would be judged unsafe to drink. Although in the industrial world we don’t often drink rainwater, many people around the world expect it to be safe to drink and it supplies many of our drinking water sources,” Ian Cousins, a professor at Stockholm University’s Department of Environmental Science, and the lead author of the study, says in a news release.
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256bits said:
...many people around the world expect it to be safe to drink...
That's pretty misleading. Usually, rainwater is NOT recommended for drinking, to start with. To met the usual standards relevant for drinking water it requires proper maintenance of the harvesting/storage equipment and even: additional treatment.
You know, rain is the washing water of the atmosphere o0)

The 'safety level' aimed in those guidelines are far beyond the available in places where rainwater is the usual drinking water.

Also, it's about regular consumption and not about occasional 'fun in the rain'.

As a warning it's still stands. Though we could learn from the first few warnings since there was plenty of them already :frown:
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Rive said:
Usually, rainwater is NOT recommended for drinking, to start with. To met the usual standards relevant for drinking water it requires proper maintenance of the harvesting/storage equipment and even: additional treatment.

I have been to places in Hawaii where many people, in certain areas, only use water collected from the runoff of their roofs.
It is stored in a large cistern and filtered (charcoal maybe UV to sterilize, but could do an RO (reverse osmosis) easily) before use for drinking.
The ground was very porous volcanic rock. Any ponds were connected to the ocean through the ground water in the porous ground. Pond water levels went up and down with the tides and the water was brackish (partly salty). The only available water for drinking was rain water. Its not your normal human environment. Proper technology makes it feasible.

Drinking rain water could well be a problem.
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All ground water was rain water before it became ground water. While the ground may filter the water to some extent, the filtration may be limited and could potentially decrease over time, especially with fractures or channels developing in the ground, which surfactants can induce.

As far as I heard, its PFOA and other PFAS compounds. "Perfluorooctanoic acid (PFOA) is one of a group of related chemicals known as perfluorinated alkylated substances (PFAS). This group of chemicals is commonly used in non-stick and stain-resistant consumer products, food packaging, fire-fighting foam, and industrial processes."

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I ran across this news on Twitter a few days ago and was curious if it was just "News Flash!" hyperbola or did the original paper actually say "no rainwater in the world is safe to drink".

I'm not sure what they're saying here;
"It is hypothesized that environmental contamination by per- and polyfluoroalkyl substances (PFAS) defines a separate planetary boundary and that this boundary has been exceeded."
Can anyone translate that into English?

The original paper only lists 16 sites checked and half were in China. That seems like a fairly small sampling to me.

I then checked with my local water utility as we primarily use rainwater collected in the mountains. According to them, no PFAS was detected in 2014, 2015, nor 2018, which was within the range of the study dates. [ref]

I think this is surprising. From the EPA; "They are not regulations and should not be construed as legally enforceable Federal standards.". [ref]
So, as far as I can tell, there are no federal laws on the levels of these chemicals in our water supplies.

Leading to comments like this in the original paper;
"PFAS drinking water guidelines have progressively decreased over the last 22 years. For example, in the US the PFOA drinking water guideline for West Virginia was 150 000 ng/L, which is higher by a factor of 37.5 million than the recently announced US EPA drinking water lifetime advisory for PFOA of 4 pg/L."​
[bolding mine]

Ha! According to this website, Nevada is even worse, at 667,000,000 ppt. 130 million times the level specified in California(5.1 ppt).

note: according to the USGS, 1 part per trillion ≈ 1 nanogram per liter (ng/L)
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256bits said:
Goodbye to incineration >400C
Hello to a simple method to break down the strong bonds of PFAS ( some ) with mild heat, a solvent, and sodium hydroxide.

Who would have thought?
The explanation of the process of oxygen atoms falling off, then carbon, seems so simplistic.
Interesting comment in that article; "... these standoffish compounds don't react to anything--not biological or other chemical agents."

How can they be dangerous if they don't react to anything?

I'm starting to wonder if this is some conspiracy by Big Cookware to get me to replace my 30+ year old teflon coated pots and pans?
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This reminds me of how we got rid of the very strong and nasty mutagen (ENU or Ethyl nitrosourea) we used to make zebrafish mutations.
Screen Shot 2022-08-23 at 11.25.21 AM.png

We would make gallons of this stuff and have to inactivate the mutagen before disposing of it. A simple mixture of NaOH and Sodium thiosulfate at room temperature for several hours did the job.
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PFAS are not plastics. They’re surfactants. The fact that the MSN article gets this wrong doesn’t give me faith in the rest of the article.
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  • #11
OmCheeto said:
I'm starting to wonder if this is some conspiracy by Big Cookware to get me to replace my 30+ year old teflon coated pots and pans?
You mean after 30 years they are still teflon coated.


1. What is PFOA and PFAS?

PFOA (perfluorooctanoic acid) and PFAS (per- and polyfluoroalkyl substances) are human-made chemicals that are used in a variety of consumer products, including non-stick cookware, waterproofing materials, and food packaging. They are also used in industrial processes and can be found in firefighting foam.

2. How do PFOA and PFAS end up in rainfall?

PFOA and PFAS can be released into the environment through various means, such as industrial discharge, landfills, and wastewater treatment plants. These chemicals can then travel through the air and eventually be deposited onto the Earth's surface, including rainwater.

3. What are the potential health effects of PFOA and PFAS exposure through rainfall?

PFOA and PFAS have been linked to various health concerns, including developmental and reproductive issues, liver and kidney damage, and increased risk of certain cancers. Exposure to these chemicals through rainfall may also lead to contaminated drinking water sources, further increasing health risks.

4. What is being done to address PFOA and PFAS in rainfall?

The Environmental Protection Agency (EPA) has set health advisory levels for PFOA and PFAS in drinking water and is currently working on developing regulations for these chemicals. Some states have also taken action to regulate and restrict the use of PFOA and PFAS in certain products. Additionally, companies are becoming more aware of the environmental impact of these chemicals and are taking steps to reduce or eliminate their use.

5. How can individuals reduce their exposure to PFOA and PFAS from rainfall?

Individuals can reduce their exposure to PFOA and PFAS by avoiding products that contain these chemicals, such as non-stick cookware and stain-resistant fabrics. It is also important to properly dispose of products containing PFOA and PFAS, as well as to support regulations and initiatives aimed at reducing the use of these chemicals. Additionally, using a water filter that is certified to remove PFOA and PFAS can help reduce exposure through drinking water.

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