The issue is not teflon, or similar plastics, but byproducts and precursors of their manufacture. They're chemically super-stable (since, like teflon, they are perflorinated) and super unreactive. That means that they persist for a very long time (until enough UV deteriorates them).
However unreactive doesnt mean harmless. Sure, they have very low acute toxicity, but they still take up volume. Therefore, they interfere with the chemical reaction rates and pathways in your body.
Its called steric interference, which is a fancy way of saying "something is in the way". Think of a very busy line kitchen and some guy is randomly and blindly walking into things and people.
Have they really been phased out in food packaging (say, in Europe)?
I thought PFAS is what is used to give grease and water resistance to food packaging (boxes, wrappers, bags, cups, etc).
If so, what have they been replaced with?
Historically they were replaced with other, poorly understood, but similarly bad materials.
For instance, PFAS replaced PFOA’s, and now they are considering replacing PFAS with PFAS [not a typo]:
https://www.epa.gov/assessing-and-managing-chemicals-under-t...
Not sure what harm you attribute to the wheel, but the harms of fire and combustion engines are currently world-class problems, such as the climate. Very much "if we knew then what we know now" situations, and with PFAS and the like, we have the opportunity to act before it becomes an issue.
Many people in history has been crushed, sometimes lethally, under various wheels.
If we go by circumstance, anything can be a danger, or a non-danger. And the solution is to be more mindful of our circumstances. What we're trying to identify in this thread are the practices that, while being immediately beneficial, are also immediately negatively impactful, even if it took us years (dozens, hundreds, or thousands thereof) to learn about the negative impacts. And following that, to be more mindful of which practices may have similar negative impacts, and be forward thinking about that possibility rather than reflectively regretful.
We certainty all do not need teflon pans. Or cars. Without massive production, such problems would be "just" local anomaly.
Not the same. Really not the same, overwhelmingly not the same.
- lab equipment since they’re extremely non reactive
- semiconductor manufacturing for the same reason as above
- coatings inside engines/hot, high wear areas, far prolonging their lives
- rubber seals preventing chemical leaks (oil, gas, antifreeze, etc)
… the list goes on. Yeah they’re a non stick coating for pans but they’re also used in an incredible number of other places.
How about we get rid of nonstick pans, gore Tex jackets and significantly reduce fluorine chemisty?
Like what? I don't think you can turn PEEK or UHWMPE into a rubber like substance...
EDIT:
If you meant that I cant turn PEEK into a plastic (as in having plasticity) - sure.
But read my comment carefully. Im not saying fluorinated polymers don't have their use cases. Im just saying that for many (but not all!) applications of perfluorinated polymers, there are alternative ways of doing things. For example wool and stainless steel make excellent alternatives for jackets and frying pans.
Should nuclear (re)processing plants ditch teflon when dealing with UF6? Probably not. Should my gas fittings need teflon tape? No, alternatives exist.
As it is, if you buy a “ceramic” pan, you get some teflon knockoff instead of Le Creuset style stuff.
That'd be a hard sell though since it seems like part of the issue was manufacturers burying research and denying any knowledge of problems while selling these chemicals as a miracle cure of sorts
These chemicals were put into basically everything, like asbestos was. Cleaning products, spray grease, fabrics, paper, shampoo and cosmetics, stain-resistant coatings.
Say you have an API that lets you bulk fetch an Item (`getItems(Collection<UUID> itemIds, int pageNumber, int pageSize)`), but the API enforces pagination and also requires authentication. A Client could require instantiation with whatever is required for authentication (`ic = new ItemClient(authToken)`), and provide a method to retrieve a huge list of Items without worrying about pagination (`ic.getItems(itemIds)`).
Every PFAS study I read seems to be pointing to ever increasing accumulation and harm. It's not hard to imagine a phase shift to a PFAS effect pandemic if we don't seriously consider PFAS curtailment as a regulatory priority.
If person A claims “the earth is round”, person B can find sources to prove it faster than it takes to write a comment. If person B did search and found the studies lacking, they should open with that and ask for clarification. Otherwise it looks like they’re waiting for person A to do all the work so they can nitpick every source and derail the conversation away from the broader, productive, important points.
I searched for “microplastics marine ecosystems” (taken directly from your parent post) and my engine returned more studies than I know what to do with. The first five links:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7927104/
https://pubmed.ncbi.nlm.nih.gov/21742351/
https://journals.openedition.org/factsreports/5257
https://progearthplanetsci.springeropen.com/articles/10.1186...
I can tell you didn't even read your "sources" since the one I randomly picked, the 2nd one, has the conclusion "Bioavailability and the efficiency of transfer of the ingested POPs across trophic levels are not known and the potential damage posed by these to the marine ecosystem has yet to be quantified and modelled."
It basically says the harm is unknown.
Rest assured I am aware of the conclusion of each, just as I am aware of which ones are the best choices to nitpick.
"Destroying". So clearly your position is based on studies. Why would you just share search results and not the studies that prove microplastics are "destroying" ecosystems.
https://www.scientificamerican.com/article/reproductive-prob...
Probably not a huge problem based on the fact that I don't like thinking about it.
>Meanwhile, the total fertility rate worldwide has dropped by nearly 1 percent per year from 1960 to 2018.
That can't possibly be also due to demographic changes[1]? Fertility in the west started to drop way before the invention of PFAS compounds, and the worldwide rate dropping can easily be explained by the rest of the world experiencing the same demographic transition.
Do the demographic changes also explain plummeting sperm count?
We don't need to be looking for a singular answer here. Yes there are obviously demographic, cultural, and economic components. But we also know that PFAS are hormone-disrupting and they're all over our food, water, and material supply.
About that... https://news.ycombinator.com/item?id=34830936
tl;dr the data does show a vague decline, but it's also very noisy so it's hard to know whether it's really happening. Also, it's not clear that "plummeting" sperm count would lead to "plummeting" fertility. A 50% drop in sperm count doesn't equate to a 50% drop in fertility, as long as there's "enough" sperm. So far even with the drop it looks like there's "enough".
> Of course it can possibly, and almost certainly is at least in part, caused by demographic changes.
From the GP:
>With all the inconclusive studies it compels me to believe that even if it's harmful, it's no so harmful.
The claim that isn't that there's zero harm from PFAS, it's that the harm is negligible. However, the article you linked seems to suggest that PFAS is single handledly cutting the world fertility rate by half.
Looking at those two pieces of information alone, it’s naive to say “well we haven’t conclusively drawn a causal population-scale link between cause and effect.” It is incredibly difficult to eliminate all confounders at that scale and time horizon, which would be really dooming to the hypothesis if we didn’t already have separate knowledge of the mechanics.
The Bayesian priors are: PFAS are poisonous to humans (known). PFAS are everywhere in our environment (known). We are seeing population-scale effects similar to what you’d expect to see from population-scale PFAS poisoning (noisy).
The difficulty of finding sound causal links at generational, population scales cannot prevent us from taking action on things — again — we already know are poisonous to people and to which people are frequently exposed.
It's a leap in logic to go from "PFAS impairs reproductive health" to "PFAS is a significant contributor to fertility decline". Your bayesian logic does not make sense. We know of dozens of other factors that are also casually known to lower fertility, and are pervasive in our society/environment. They can be contributors, but they can't all be significant contributors.
Again, repeating my prior comment: I'm not claiming PFAS generate zero effects on fertility. I claiming that there isn't good evidence that it's a significant factor in fertility decline.
Makes a lot of sense!
Note, this doesn't necessarily mean that we should do nothing about PFAS. We just have to be honest about the potential impacts. In other words, instead of gesturing that PFAS is the primary cause for fertility decline in the past few decades (like the linked scientific american article), you admit that the impact is unclear/low, but we should still work to remove it just in case.
Because it's the best available theory and even if it's wrong we're eliminating known toxins from our environment?
What other theories have an established mechanism of action and established population-scale exposure? That's why this one should be prioritized above others (at least any that I'm aware of?). Which other theory has these?
Another reason: if any portion of decline is due to these, the damage builds across generations. If this is any problem at all, it will grow to a big problem.
We’re talking about future generations not just getting poisoned during their lifetimes, but being born poisoned, too.
This is either not a problem at all or it should be extremely high priority, and I think the former position is completely non-viable at this point.