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Comment by hcurtiss | Hacker News Reader

PFOA/PFOS propaganda is wild. They're very useful substances. Yes, acute exposures cause harm, but the same can be said of salt. Though with modern instrumentation we can measure presence in parts per trillion, I have seen no evidence at all that likely bioaccumulative pathways have resulted in harm to humans. Even the opening of this article levers "we found it" with "EPA regulates it in drinking water" as self-evident that it's some kind of super poison. But it's not. Frankly, it's not always even clear what "it" is as there are thousands of different compounds, many of which people consume daily (e.g., flonase, prozac, etc). The health alarm around these substances is just astounding to me.

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Ironic, just about every time I see industry propaganda that defends some toxic chemical, they use two tactics. First, compare it to something else everybody uses and considers harmless. Second, repeat over and over again there's no studies that show it's harmful at very very low doses.

You managed to do both.

That's because these are generally valid arguments. The phrase "the dose makes the poison" did not just occur in someone's head for no reason.

There's a couple things to note about "forever chemicals":

They're around "forever" because they are extremely unreactive. The concentrations the public is concerned about are ridiculous. With such small concentrations, huge timescales for the cause-effect chain to take place and countless confounding factors in between it's basically impossible to make the bold claims the general public makes.

That being said: Workers are exposed to much higher concentrations and they should have been protected from it. New chemicals shouldn't be used as widely as they do by simply assuming they're safe. There are uses (like cosmetics etc) were no risk is really warranted so they should be more restricted with what they use.

At the end of the day though, when you ban something you need to really understand and take into consideration what kind of damage you'll do to people by banning a substance and all the products that depend on it vs. what kind of damage the substance will do. You can't pretend that you can just ban a whole class of really important compounds without any societal side effects.

And that's coming from someone who's really concerned about dangerous chemicals. If you know chemistry, and look around you, you can tell there's a lot more dangerous issues than PFAS that aren't being tackled and nobody seems to care about. Primarily how nobody seems to check what's really included in tons of "cheap" (in terms of manufacturing, not always of price) imported cosmetics, personal hygiene products and parapharmaceuticals.

People are buying protein powders and supplements of unknown producers, raw materials and manufacturing methods by the kilos, plastic cooking utensils from the internet and boil/oven bake them with their food, buy sketchy adhesives for their PVC water pipes, and then complain about some 1ppt concentration of inert chemicals in their drinking water. I understand how the public is easily swayed on things that are technical, and I am happy with people being aware of potential dangers, but the focus is really misplaced on something that looks new, scary, unsolvable and interesting instead of tackling the old, boring but important and serious issues we come across every day.

The phrase "the dose makes the poison" did not just occur in someone's head for no reason.

What dose of PFOA/PFAS is harmful instead of harmless?

What dose of any substance is harmful instead of harmless? Is this a philosophical question or a practical one? If it's a practical one, we don't know, because if there are any effects they're too weak to infer with certainty. Unlike for example those of benzene in your sunscreen or acne products, or flame retardants in your furniture.

For PFOA, based on animal trials, somewhere above 10–70 ng/kg body weight-day.

They must work for one of these companies. The last 6 months of their post history is a majority of just showing up when an article like this appears and defending PFAS and other types of chemicals or poisons.

I work for a lumber company. We have no connection to, or use of, any of these substances. I just work on toxics issues in different arenas (e.g., air toxics and pesticides).

Then please point out the studies that show they are safe for the human body.

I would enjoy seeing the studies that show they are harmful in the doses that humans are exposed to as well, I don't know much of anything about this subject.

the studies are described in the article

> What Hansen didn’t know was that 3M had already conducted animal studies — two decades earlier. They had shown PFOS to be toxic, yet the results remained secret, even to many at the company. In one early experiment, conducted in the late ’70s, a group of 3M scientists fed PFOS to rats on a daily basis. Starting at the second-lowest dose that the scientists tested, about 10 milligrams for every kilogram of body weight, the rats showed signs of possible harm to their livers, and half of them died. At higher doses, every rat died. Soon afterward, 3M scientists found that a relatively low daily dose, 4.5 milligrams for every kilogram of body weight, could kill a monkey within weeks. (Based on this result, the chemical would currently fall into the highest of five toxicity levels recognized by the United Nations.) This daily dose of PFOS was orders of magnitude greater than the amount that the average person would ingest, but it was still relatively low — roughly comparable to the dose of aspirin in a standard tablet.

the only propaganda about PFOS was made by 3M, telling us these chemicals were safe, when they knew they weren't.

They asked for a study that showed they are harmful in the doses that humans are exposed to. That study was for orders of magnitude greater than that.

> This daily dose of PFOS was orders of magnitude greater than the amount that the average person would ingest

Like countless substances both natural and synthetic, they appear safe enough if you don't eat a substantial amount of them. How do the quantities involved in the studies compare to the levels we end up consuming? Nobody ever seems to address that.

since these chemicals accumulate in the body, if we're absorbing them from the environment they could reach toxic levels. but what if we don't measure toxicity just by death, but by worsening health? if i or my child has some mysterious ailment, how do we know it's not from PFOS chemicals, or many of the other synthetic chemicals industries have been pumping into our air, water, and earth for decades?

to wit: lead dropped the average iq of the americans since 1940: https://today.duke.edu/2022/03/lead-exposure-last-century-sh...

how do we measure this kind of toxicity, except well after the damage is already done? if we know something is toxic, why don't we stop using it?

Because everything is toxic in large-enough quantities.

Threads like this always end up semantically identical to the Unabomber's manifesto. Sometimes that kind of throw-the-baby-out reaction is justified, as in the leaded-gasoline example, while sometimes it's not.

this is some real bad faith arguing saying my point is semantically identical to the unabomber manifesto. i really don't think it's close to that, since i'm not arguing for any kind of primitivism, nor for killing people to get there. and if you agree that this throw-the-baby-out reaction is justified sometime, maybe this is actually one of those cases?

the point of the article, and what i think you're ignoring, is the decades of cover-up by the corporate producers of these chemicals to protect their profits. that's not a good look if they're convinced their products are worth the damage

> Because everything is toxic in large-enough quantities.

We mostly don't take things in the large-enough quantities to make them poisonous. We cook on teflon for entire lifetimes, scraping food off of it, throwing out the pans when we visibly see the coating coming off.

> Threads like this always end up semantically identical to the Unabomber's manifesto.

No, they don't. But suggestions of regulation or political change somehow always get compared to terrorism.

Not all of them accumulate, only those with a certain range of molecular weights and chemical signatures.

This sounds like the study on the residual coffee material injected in rats that obliged California to say coffee causes cancer.

In exactly what way does it sound like that? Did coffee companies find out that about a asprin's weight of coffee grounds would kill a monkey, and suppress that information?

Or is it because just because that you think it's not important that a study found that some aspect of coffee could cause cancer in rats, and you also don't care about studies about PFOAs, so they're the same?

In that everything is poisonous at the right dose.

That's not how it works.

Your statements do not have the effect you intended. I am now interested in studying the pro-PFOS pollution propaganda and its sources.

Yes, acute exposures cause harm, but the same can be said of salt.

Experience has taught me that anytime someone pulls the "well, technically, water can poison you in large enough doses" card, an intellectually dishonest conversation is about to follow. This one is no exception: the "well, technically..." card is played, followed by repeated statements of "...ergo, I don't see what the big deal is", and a hefty sprinkling of some whataboutism for seasoning.

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