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This is probably one of the most prominent studies till date: https://pubmed.ncbi.nlm.nih.gov/38446676

Microplastics and nanoplastics in atheromas and cardiovascular events. N Engl J Med. 390(10):900-910, 2024.

Summary: People with artherial plaque that contains micro- and nano-plastics have a higher risk of death during the followup period. It's an observational study, sample size is not too big, but some findings look quite mechanistic suggesting causality, e.g. "electron microscopy revealed visible, jagged-edged foreign particles among plaque macrophages and scattered in the external debris". The effect size induced by microplastics on death risk also looks substantial.

Personally, I think microplastics are a very important pollutant, and evidence of this will unfold during the next years. Sadly, it is extraordinarily hard to remove them from our environment. They are everywhere. For example, car tires shed lots of microplastics that end up in eggs or inside vegetables and plants, which absorb them from soil. Most liquids are packaged inside plastic, which is continuously leaking into the content. We should at least be measuring their levels and setting up maximum concentration thresholds in our food chain. We should go back to glass bottles, whenever possible. Suspended microplastics in the air are also a major concern. Plastics are great for certain applications, but we use them in places where they don't belong.

> For example, car tires shed lots of microplastics that end up in eggs or inside vegetables and plants, which absorb them from soil.

Last year I moved to a house with a greenhouse and started gardening, and was surprised not only by the amount of plastics used, but by the amount of UV unstable plastics used.

- Previous owner used polyester string to tie up plants, which now just disintegrates whenever I touch it. I had to go out of my way to find jute twine.

- I bought agricultural fabric to cover plants during spring. I left it at the top of the greenhouse over the summer to provide shade. By autumn it was disintegrating as it was not UV stable. Again I had to go out of my way to buy a UV stable polyester sheet that I will use now.

True. The paradoxical thing is that even organic agriculture doesn't currently care much about microplastics given that they are not tested. It's a huge blind spot.

People don't even care about the atherosclerotic effect of saturated fats and lipoproteins that we've known for half a century.

What are you even talking about? Every single physical revolve around that with plenty of lectures from doctors and everyone talks about it all the time.

>We should go back to glass bottles, whenever possible.

There are very good, very practical reasons we moved from glass (and metal and other materials) containers to plastic. Unless those factors are sufficiently addressed, plastic is here to stay.

For those who haven't been keeping track or are just too damn young to know history, those factors include:

* Weight. Glass and metal, and also other materials like ceramic and wooden containers, are heavy compared to plastic. This additional weight means it takes more energy to transport, meaning more costs in fuel and labor.

* Fragility. This namely applies to glass; glass containers are fragile and they are very dangerous to handle if and when they break. Plastic containers are much more durable, and even if they break they are seldom as dangerous as broken glass. More broken containers also mean more goods lost to spillage, which in turn means additional cost to re-manufacture and re-ship.

* Durability. Going along with the above, plastics are equal to metal containers in keeping contents and the outside world separated. This is incredibly important for ensuring food safety.

* Contaminants. This applies primarily to metal containers, but also paper and sometimes ceramic. Metals leach into foods, this is mostly prevented with special coatings but it's not perfect and the coatings themselves are also contaminants that will eventually leach. Likewise paper containers which have coatings applied so liquids don't seep through, and sometimes ceramic containers to prevent leaching. We know these contaminants are bad, unlike microplastics where we still aren't conclusively sure.

* Cost. Plastic is cheap compared to basically every other material we can make containers out of. This is a great boon to the consumer who ultimately ends up paying the most markup.

I agree with every point here, and they all make a lot of sense... yet most alcoholic beverages are shipped to the consumer in glass bottles, including even the cheapest beers.

I have seen some drinks shipped in plastic, so it is possible to do, I wonder if glass packaging is a 'premium' thing. Though, if they can do it for cheap beer, then I'm sure they can do it for non-alcoholic drinks on scale.

It's about reducing costs for the producers and supermarkets, ignoring externalities. That is, tons of plastic that doesn't get recycled and goes to the landfill. Now the issue seems worse as another important externality are adverse effects to human health.

I can't believe costs of switching to glass or ceramic are that high. I've bought tons of inexpensive dairy and desserts that came packaged using those materials. But since most customers don't care, they tend to use plastic.

I've seen and had alcohol in plastic. They generally seem to do fine.

But damn did it feel cheap in a bad way. Being cheap is obviously one of the reasons we use plastic containers, but the feeling associated with plastic alcohol is just plain irrationally bad.

a 500 ml Al can weights 13 grams. life knows if we can skim down its weight if we don't have self openers, the price if we develop a better recycling system etc.

if plastics have impact on human health, how many $ we can save for using re-usable glass and metal?

Aluminum cans are lined in plastic.

I think it's about steel cans?

Some EU supermarkets used to have a circular glass system where products were brought in bulk, and only canned in glass inside the shop, sometimes by the customer. Bottles were then returned after use, washed locally and reused many times. This looked fairly efficient.

Restaurants and bars still have the same system here for e.g. Coca-Cola drinks, which come inside a glass bottle that has been reused several times. I'm not sure plastic is more efficient than reusing a glass bottle. Lots of yogurts are packaged in glass containers, and price seems average. I have also heard that plastic is rarely recycled, so it also sounds unsustainable from that perspective.

> cost

Oh yes, I love paying a couple cents less per drink to have micro plastics in me

And - of course - you're probably not even paying a couple of cents less. Those couple of cents are extra profit for everyone further up the 'value chain'.

And yet you would get, on average, 0 microplastics from drinking out of plastic bottles since those are brand new bottles which have not been subject to UV degradation of any kind. They're also entering via the GI tract, which doesn't have a particularly high rate of foreign matter exchange with the blood stream.

Meanwhile you'll walk outside sipping your glass bottle and take a deep breath of tire dust from nearby cars, which is actually the primary route of exposure for microplastics to enter the body since the lungs do exchange particles with the blood stream (notably, you will also find silicates, soot and basically every other type of thing all throughout the body via lung exchange as a mechanism).

And when your girlfriend finds out you have microplastics in your emissions, she'll say "yay, thank you for putting microplastics in me."

in many ways it seems likely that this response was generated by chat gpt , I apologise if this was not the case

Apologies accepted.

What's the toxicity of microglass particulates?

AFAIK, glass is super stable. It won't shed anything significant unless you grind it, at least according to the literature.

Silica is one of the most common substances on earth — the crust is more than half silica by mass. Pretty much all life can, by necessity, tolerate a good deal of silica exposure. You don't really want to breathe a lot of fine silica dust (or, frankly, any size of glass bits), but actively grinding it into dust that gets airborne is just about the only way it'll cause problems, other than cutting yourself.

So glassware is safer than plastics? I'm not going to get bits of glass in my brain just from drinking soda out of bottles?

Yes, glassware is vastly more stable than plastics. Ever microwave something in a plastic bowl and it comes out smelling kinda plasticky? That smell means it’s degraded and venting volatile compounds that are chemically reacting with your olfactory neurons.

Smelling something doesn’t automatically make something dangerous, obviously. It does mean the molecules that were previously part of your plastic soup bowl are now knocking around in the open air.

Glass doesn’t do that at common temperatures. It’s basically inert.

You mean sand?

I was too clever by half. Dalewyn omitted safety from their criteria comparing glass to plastic.

>glass containers are fragile and they are very dangerous to handle if and when they break. Plastic containers are much more durable, and even if they break they are seldom as dangerous as broken glass.

"Being there" can be harmful in and of itself. Blocking receptors, clogging up conduits, etc. As I understand it, this is why certain elemental metals are so toxic: They're big atoms that deposit in harmful places and can't be effectively filtered out.

Also interfering with immune response https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9552327/ and directly or indirectly via immune response triggering inflammation https://www.sciencedirect.com/science/article/pii/S016041202....

True, but it could also be totally innert and not have any measurable negative effect. Who knows?

Bisphenol A have a carbon ring structure that resembles hormones like the estrogen. It can bind to the estrogen receptors and potentially increase risk of hormone related cancers.

Don't worry, we got rid of BPAs and replaced them with substitutes that probably do the same thing!

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6387873/

Small amounts of mercury and aluminum have been shown to be safe in the bloodstream. The dose is the poison

Which is why you have to take care not to eat too much seafood

True. Children and babies, even less seafood than adults

A quick search led me to this review, which has a number of studies linked in references, including a few that studied humans.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9885170/

Quote from the abstract: The direct consequences of MPs and NPs on the thyroid, testis, and ovaries are documented. Still, studies need to be carried out to identify the direct effects of MPs and NPs on the hypothalamus, pituitary, and adrenal glands.

Disappointingly nothing in that study relates these health impacts to known levels of microplastics in humans. That means there’s no way to tell, from that study, if the levels of microplastics to be found in you and me are likely to have material impact.

I definitely feel we should be more serious about reducing use of plastics, especially for uses likely to contribute to microplastic levels, but it’s going to be hard to convincingly make that case without quantifying these risks in relation to actual human microplastics levels.

One doesn't reduce the use of plastics without using something else as a replacement.

If we replace all plastic cups with glass cups, might we get micro-glass inside ourselves instead?

Glass, mostly silicon dioxide, might sound harmless, but glass can chip off in microscopic sharp fragments (think fiberglass dust - which some suggest might be as bad as asbestos). Glass also slightly dissolves in water (this is how glasses start to look frosty after enough dishwashing - they're dissolving), and slightly evaporates (everything has a vapour pressure!). And obviously the glass isn't pure - there can be all kinds of deliberate and accidental additives.

Am I worried about glass? No. But it seems naive to wholesale replace plastic with something else until there is a decent understanding of the replacement.

I disagree that replacing plastic without a decent understanding of a replacement is any more naive than continuing to use plastic without a decent understanding of the implications of plastic. Glass for one has been used for at least an order of magnitude longer than plastic has, without the mentioned issues of microscopic sharp fragments, dissolution in water, evaporation etc. causing harm. It seems clear to say that going back to glass and ceramics would be - on the balance of probabilities - likely safer, as they don't cause bioaccumulation to anywhere near the same extent, and history hasn't shown any comparable dangers which persist today.

I think we can find and should seek out easy wins. That is we should identify the major sources of microplastics and eliminate them. From my personal observation it seems the major issue could be textiles made from plastic. Clothes and carpets made from polyester, nylon, I would guess these are subject to a lot of wear and tear and rubbing which produces plastic dust that may be breathed.

The clothes dryer is a major culprit, as it turns fabric into lint especially when the fabric is mostly dry. The appropriate care for plastic clothing is to at least end the drying on a clothes horse or clothesline. The horse is a great way to get cotton relatively wrinkle free and not turn your favorite shirts into dryer lint. But it's a bit more labor-intensive to set up that drying, so it's unlikely to catch on.

This is completely inaccurate and disingenuous. Glass suffers from no such thing as "microglass", unlike plastic. Plastic actively sheds micro/nanoplastics into bottled water, with hundreds of thousands of particles (and probably more depending on its handling) floating in the water, along with any chemicals used to make plastic moldable, fire-retardant, etc. Glass bottles have no additives that leach out in anything but the most minute quantities, even in an alkaline solution. The same can't be said for plastic containers.

Also, while glass does dissolve in water, it is an extremely slow process that does not affect containers at room temperature in any significant way. As for the claim about glass evaporating due to vapor pressure, while technically true, the vapor pressure of glass at room temperature is so infinitesimally small that it's completely irrelevant for practical purposes. This process occurs at such a slow rate that it would take far longer than the age of the universe to have any measurable effect on a glass container.

> disingenuous

How about we leave the silly accusations of malice at whatever low rent other website they were learned at. You don't know motivations.

The term 'disingenuous' isn't about malice, it's about misleading comparisons. Equating the well-documented issue of micro/nanoplastics with hypothetical (and inaccurate) risks from glass muddies the water on a serious environmental problem. If you want to dispute the facts I presented about glass versus plastic safety, let's focus on that instead of tone policing.

Saying you don't know someone was being disingenuous isn't tone policing. It's nothing to do with tone.

Ok, disingenuous and/or stupid.

> they're not very reactive, and this lack of reactivity could mean they're not actually that harmful.

Per- and polyfluoroalkyl substances (PFAS) are so stable they are called "forever chemicals", but according the NRDC, "PFAS are also toxic at extremely low levels (i.e. parts per quadrillion), posing significant risks to our health":

https://www.nrdc.org/stories/forever-chemicals-called-pfas-s...

You can back that question up one level to "what are the biological effects of plastics?"

And the answer is, broadly, they mimic hormones. Compounds in plastics can activate endocrine receptors because they are similar enough to hormones which are more or less everywhere across the animal kingdom.

Sometimes it can be hard to pin down the specific negative effects in isolation, but there are some pretty clear metrics.

"A review of the endocrine disrupting effects of micro and nano plastic and their associated chemicals in mammals" https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9885170/

The most common plastic, PET, is inert and does not mimic hormones

This is not correct.

"When comparing water of the same spring that is packed in glass or plastic bottles made of polyethylene terephthalate (PET), estrogenic activity is three times higher in water from plastic bottles."

https://www.sciencedirect.com/science/article/pii/S096007601...

PET in consumer products has a lot of contaminating non-PET plastics, precursors and other chemicals co-present, which can lead to the effects you cite.

If you were to get a block of lab grade PET you’d find it was inert

Based on a similar search, my take away was that it’s too early to tell. Animal models suggest some risks, but it’s not very clear if that translates to humans. Feeding plastic to mice isn’t an exact analogue.

Here is one on human GI track

"Micro- and nanoplastics in the body are passed on during cell division"

https://www.sciencedaily.com/releases/2024/03/240306150719.h...