A Concerned Scientist @BE@qoto.org

@datum

I know you're scientifically literate, so rather than dumbing it down some, tell me if this answers your first question:

https://www.asdwa.org/wp-content/uploads/2021/02/ASDWA-PFAS-Lab-Testing-Primer-FINAL-02032021.pdf

If not, definitely ask more questions.

The basic answer to the activated charcoal vs. RO from my standpoint is two-fold.

One, in short, I've seen various tests with some different results. I think if you think about activated charcoal like column chromatography, length, time and temperature all matter. I've seen various numbers coalescing around 80-ish percent, though, and that's probably a fair number, but, real life results will differ.

Specifically, I've sent this to a couple of people because the supplementary data to this paper lists out some exact brands of filters that they used under real life conditions(it's not too hard to get the number you're looking for, for just one chemical in the lab). I stumbled on it looking for something else recently, and Berkey filters must be popular because at least three people asked me about it and they tested three of them, for instance.

https://pubs.acs.org/doi/suppl/10.1021/acs.estlett.0c00004/suppl_file/ez0c00004_si_001.pdf

Two, I always have to say this even if you know it, RO's just more comprehensive. There's always stuff that you just don't know about in there, and RO's going to get more of it.

Honestly, the Swiss cheese approach works here, too. I have a whole home filter that filters everything coming into the house, and THEN I run the drinking/cooking/dishwashing/ice making water through RO.

@NilaJones

I have read that the Aura-specific thing was about the straps. I don't know if that's fact? I just haven't seen a source on it. I am assuming that it is, though, and that's part of why I'm attributing it to manufacturing contamination rather than intentionally making the mask, itself, waterproof with PFAs.

More in general, the study that included just 1 N95 alongside 6 cloth masks and a firefighting mask wasn't Aura specific, but, did give tenth of a microgram precision numbers. So I thought that would make a good test case for scale.

The fact that more or less random cloth tested higher for PFAs than the N95 tells me that it's likely manufacturing contamination with the N95. Manufacturing parts are a mess in that regard.

Math time!

The paper cited above about PFAs in masks was designed to study their accumulation in dumps. I don't want to gloss over that, but, I'm going to anyway.

On an individual mask basis, you have to do some math to figure out how much PFA contamination you're talking about, because they were looking at it per square meter of mask materials.

The N95 in the study tested out at 15.2 micrograms per square meter. Your mask is obviously not a square meter.

I'm going to make an assumption and do some rounding here, just to get a ballpark number.

I pulled a 3M Aura off of a hook by our door(my wife wears one to get the mail, or slap on if the FedEx guy keeps knocking and won't go away) and a quick measurement tells me it's around ~6" x 8" or about 300 square centimeters. There's 10,000 square centimeters in a square meter, so, one Aura mask is roughly 3% of a square meter.

15 * 0.03 = 0.45 micrograms of 3 PFAs combined on a single mask. Most limits for PFAs are listed in ppt(ng/L) or ng/kg body weight. So, 0.45 micrograms is 450 nanograms.

So, in that same ballpark, what does it mean?

*I am not saying that there is a "healthy" PFA dose. Your body struggles to get rid of it and it doesn't ever break down.*

The European Food Safety Authority says that the tolerable weekly intake of PFAs is 4.4ng/kg of body mass. That would mean ~220 pound person could eat their N95 every week and stay within the limits(please don't).

The state of Virginia says that your water can legally contain 150,000 ng/L. In Virginia you could drink 333 N95's worth of PFAs continually(please don't).

Under the new EPA guidelines that will go into effect, maybe, years from now water must be under 4ppt. So, one N95 might contain the amount of PFAs in a month's worth of your drinking water if you drank 3L a day, and if that goes into effect and is enforced.

What does it mean for what you're actually exposed to already?

In a study some paints had upwards of 700 ppm total Fluorine. If, as expected, the PFA in the paint formulation was 6:2 FTOH, that would be around 50 ppm of that PFA, or 50,000,000 ppt. Thank goodness we don't ingest paint, but, I'm willing to bet we're all surrounded by it. How well encapsulated is it?

https://habitablefuture.org/wp-content/uploads/2024/03/97-pfas-in-paints.pdf

In a bad scenario, my friend who is now facing kidney failure has been drinking neighborhood water that was tested at ~59,000 ppt in 2016 for a couple of decades, or so. He may have been drinking upwards of 180,000 nanograms a day. That's the same as ingesting 400 masks worth A DAY. I do not recommend this.

https://www.ewg.org/interactive-maps/pfas_contamination/#about

Even in rain water, tested amounts of PFAs were between 1 and 40 nanograms per liter in urban environments, or, often upwards of an N95 masks worth of PFA for every 10L of rain water.

https://pubs.acs.org/doi/10.1021/acs.est.2c02765

Yes, there's studies that absorbing PFAs through the skin is similar to ingesting them.

https://www.sciencedirect.com/science/article/abs/pii/S0278691520300016

If the data we have on N95's is in the right ballpark, it's just not high on the spectrum of PFA concerns in my opinion.

@OpenComputeDesign

Ours does the same thing! I assume some don't, and I used to tell people to talk to their own instance's administration about their problem. Now I just block them so they don't have to see it anymore :)

@QuietLurker

I appreciate that. You are welcome to either publicly or privately ask questions any time, too. I get regular DMs asking about something I wrote and I'm always happy to explain more as best I can.

@Wraithe

😂 So true

@JaminBogi

I've been hunting my woods for pawpaws unsuccessfully for years now. I think I'm going to have to plant them myself. I hope yours are doing well!

@ClimateJenny

Character limit was my most researched feature when choosing an instance if I'm being honest 😬

Over 65,000 here, but I don't think I'll ever test that 😂

I've written this and deleted it a few times. Which is probably good because each one has become less of an angry rant with less profanity 😂 There's really no need to read it and I'll warn you up front of that fact. I'm just venting for my own sanity about 3 separate people in the last 24 hours telling me various versions of "Your posts are too long for me."

Look, simply put, I don't care if you are offended by the length of my posts. I don't care about your precious timeline. I don't care that you don't have the time to "read it all." Is this some sort of weird entitlement that because you can curate your feed here, I'm supposed to post how you want? I'm not ChatGPT. I'm not summarizing science for you, on command. I honestly don't know why every time something I write gets over a certain number of boosts people come out of the woodwork to tell me this.

I'm not offended when someone clearly doesn't read and replies anyway. Chances are good that I blocked the person complaining already, which is why they're off sub tooting about me. Yes, I do understand that there's at least two of those this morning. I *love* the block and mute buttons. Seriously.

I'm not for everyone and I'm not trying to be. I don't need a course on scientific communication, although I enjoy the subject and am pretty much always willing to discuss it. I love talking about science. That's my happy place. If yours is reading two sentence summaries, don't read my posts and we'll both be happier for it.

I'm sorry some of y'all were(probably literally) raised on twitter and you really believe that if you can't make a point in 200 characters then you've failed. In my opinion, that's a large part of why we are where we are in today's society.

I'm sorry you feel the need to tell me about the first 100 characters of my post without reading the rest.

I'm sorry that you feel the need to tell me that my post lengths are offensive to you.

Whether or not you Mr. I-feel-the-need-to-fire-off-a-half-dozen-DMs-to-you-while-you're-sleeping-about-how-I-need-you-to-change-how-you-post read and understand what I write is not on my list of things to worry about when I wake up in the morning.

My Mastodon origin story is that I saw a need in the world for some information curation and discussion that was largely missing. The people that I was doing that for in the real world had stopped listening to COVID information, so I had some free time already carved out of my schedule. As we get further into the COVID pandemic, honestly, there's less of a need for that. COVID is bad. Anyone bothering to read anything I write gets that. I don't need to break down yet another paper about it.

Sometimes interesting, novel things still come up, but, at this point it's largely rehashed info honestly. So now I talk about PFAs, or other pollution more often rather than preach to the choir about not getting COVID three times a year(anyone noticed a LOT of people are using that number now about themselves?). These are things I am eminently qualified to talk about and could write books on if I thought anyone would actually read them.

Why? Because it is, actually a need. You know how many people here on Mastodon have told me that they've made positive changes based on something I've written about? Dozens. And that works for me. That's why I went into science. I don't need anything more than that. Some people are going to be more healthy in the future than they otherwise would have been because I exist on this site. So, no, I don't care that you need me to "summarize my thoughts better." I'm just a guy who writes a lot of words and maybe 100 people read them regularly. I don't care if you make it 101 or not.

I could just as easily write you a 1,500 word article on the Denver Nuggets, something I've also been paid(very, very little) to do in life, but, I don't think there's a *need* for that the way that there is science.

Yes. I very purposefully sat here while drinking my tea and extended this over and over just to make sure it was extra wordy. Just the way I like it. R.I.P. to your timeline voluminous science haters!

@Brad

#ItsAMystery

@yash25571056

#ItsAMystery

@Lorrrraaaaine

#ItsAMystery