Microplastics in the human brain
smithsonianmag.comThis paper came up as a pre-print. You can't make the extrapolation that the headline is making - they're using gas chromatography to estimate quantities from 1-2mg samples, and then extrapolating to get to these scary sounding whole-organ estimates. If you look at the paper [1], you'll see that the microplastics in in situ samples are not discernible by light microscopy, and that there was a ~25% variation in within sample measurement of the GC [2], indicating a great deal of uncertainty in the precision of the fundamental measurement (the authors brush this off; see quote below).
Basically, you've got an extremely sensitive measurement system being used to make tiny measurements, and then they extrapolate these measurements by a huge factor to get to ug/g estimates. Further extrapolating (to the weight of an organ, say) when you know that there's 25% inter-sample variation, is just guaranteed to be nonsense.
[1] https://www.nature.com/articles/s41591-024-03453-1
[2] "Both analytical laboratories (UNM and OSU) observed a ~25% within-sample coefficient of variation, which does not alter the conclusions regarding temporal trends or accumulation in brains relative to other tissues, given the magnitude of those effects."
IMHO the more important part is they used pyrolysis gas chromatography, which breaks down all polymer chains.
Besides man-made plastics, guess what else has long hydrocarbon chains, occurs naturally in humans and other biological matter, and behaves similarly under pyrolysis...
https://en.wikipedia.org/wiki/Fatty_acid
Here's an interesting related article: https://www.oaepublish.com/articles/jeea.2022.04
Analysis of saturated, monounsaturated and polyunsaturated fats was demonstrated to form the same pyrolysis products as PE
To their credit, they do discuss this in the results. I suspect the reviewers had the same concerns.
Their response is not especially convincing, IMO, but they do at least discuss it.
Well, it still tells us something. What are the upper and lower bounds of whole brain microplastic content, given that 25% variation?
I couldn't begin to tell you [1]. It's not a 25% variation, once you've extrapolated from the samples by 10,000x (or whatever). The 25% inter-sample error was on a few replicas of teeny tiny measurements. The post-extrapolation error bars are so wide that they're meaningless.
The Smithsonian magazine article is garbage. Ignore it. The paper is saying that they see longitudinal trends in plastic bioaccumulation in various cadaver tissues, and this is plausible. But no, you don't have a plastic spoon in your head. That's just panic porn.
[1] Actually...I just asked Gemini and it reminded me that the expected variance of a draw from a distribution, scaled by factor C, should have a variance of the scaled sample distribution that grows with C^2. So, if we scale up the measurement by a factor of 10,000, we'd expect the variance of the scaled estimate to be proportional to 10,000^2.
I may be misunderstanding you, but it sounds like you're claiming that they had e.g. 10 tiny samples of tissue, that their measurements had an average 25% variation across those 10 samples, and that therefore the whole brain estimate (mass 10,000x that of a single sample) therefore has a much greater uncertainty. But doesn't the standard error of the mean get reduced by the square root of the number of samples? i.e. if you had 10 samples with 25% variation across samples, and you're taking their mean, the error of that mean should be 25% / sqrt(10) = 8%. And that should be the relative error for the scaled up whole-brain microplastic concentration as well. Or is there some other source of variation that I'm missing?
You're talking about reduction in statistical variance due to replication of measurement (and then averaging). I'm talking about what happens when they extrapolate from that value by a huge factor (which is what they've done, and the silly article does egregiously).
The paper isn't clear what they mean when they said "~25% within-sample coefficient of variation", so I can't directly address what you're asking, but it's tangential to the point I'm making. My naïve interpretation is that they did an ANOVA, and reported the within-group variance, or something similar.
All I'm saying in my footnote is that, whatever the final point estimate, scaling it by a factor of C will affect the variance of the final sample distribution by C^2. So for example, if you have an 8% variance on the measurement at ug/g, and you scale it by 1300 (for 1300g; what the interwebs tells me is the mass of a standard human brain), then you'd expect the variance of the scaled measurement to be 1300^2 * 8%.
That makes a ton of assumptions that probably don't hold in practice -- and I expect the real error to be larger -- but illustrates the point.
I think there is some kind of mixup, you can not scale up the variance percentages quadratically:
If you do a small-scale measurement, say you get result of 5g, with a standard deviation of 0.2g. That means the variance is 0.04 g^2.
If you then scale the setup up by 1000 (=> getting 5kg as expected value), then the variance scales to 1000^2 * 0.04 = 40000 g^2.
BUT the standard deviation is still 200g. The relative uncertainty is NOT increasing quadratically!
(another sanity check: if you change the units by a factor of 1000, your variance must not increase, relatively).
But maybe I misunderstood your point?
> If you then scale the setup up by 1000 (=> getting 5kg as expected value), then the variance scales to 1000^2 * 0.04 = 40000 g^2.
They didn't "scale the setup". They made a small-scale measurement, then extrapolated from that result by many orders of magnitude. They didn't grind up whole brains and measure the plastic content.
Imagine the experiment as a draw from a normal distribution (the distribution is irrelevant; it's just easier to visualize). You then multiply that sample by 10,000. What is the variance of the resulting sample distribution?
> What is the variance of the resulting sample distribution?
Relatively? The same. Yes it scales quadratically, but that is just because variance has such a weird unit.
Just consider standard deviation (which has the same physical unit as what you are measuring, and can be substituted for variance conceptually): This increases linearly when you scale up the sample.
An example: Say you take 20 blood samples (5 ml), and find that they contain 4.5 ml water, with a standard deviation of 0.1 ml over your samples.
From that, your best guess for the whole human (5 liters, i.e. x1000) has to be 4.5 liters water, with standard deviation scaled up to 0.1 liters (or what would you argue for, and why?)
...so you are saying that the probability distribution indicates that there is a 50% probability that there more than a spoon's worth of plastic in our brain?
Why yes, i think i will believe the random internet commenter.
Practically every internet commenter is random.
Which is fine in plenty of contexts. Rebutting this particular article? Nah.
Evaluate things based on reasoning, not source.
Evaluate based on both. Why remove any explanatory variables?
And for what it is worth, the paper itself has plenty of other interesting findings that OP fails to discuss or rebut at all. OP asks an LLM some very basic statistics questions, putting into question their ability to credibly apply and interpret the LLM's findings.
My interpretation of that evidence is that OP, a random internet commenter, just doesn't think it is credible that plastics are harmful to humans, and is grasping at plastic straws with cherry picked evidence and poor rebuttals to reach that "fact based" conclusion.
> My interpretation of that evidence is that OP, a random internet commenter, just doesn't think it is credible that plastics are harmful to humans, and is grasping at plastic straws with cherry picked evidence and poor rebuttals to reach that "fact based" conclusion.
So what? If some things haven't been discussed or rebutted, then just say that the argument is incomplete for those reasons and move on.
Remember that car tire degredation is a significant portion of microplastics in the environment. Investing in mass transit is as imperative as it was to move away from leaded gasoline.
And we need more lightweight cars , not heavier, since tire wear is proportional to vehicle weight to the fourth power. Ironically, CAFE regulations and EV incentives both did the opposite
I'm not sure why you're being down voted for suggesting a practical and fact based solution. The USA is, regrettably, not making a pivot towards public transportation anytime in the near future. So, lighter cars are one way to address this issue.
You didn't expound upon your point about the unintended consequences of CAFE standards but they're very real. Instead of making smaller and more efficient sedans per the guidelines, car makers opted start making all of their vehicles "light trucks" -- 80%+ of new vehicles are SUVs or bubbly looking "crossovers" -- which are not subject to the same demanding standards. Small sedans also cost less and would require ongoing R&D to continue to meet the CAFE standards. The end result, as this thread is interested, is heavier vehicles with bigger tires and more plastic in the environment and our brains.
Los Angeles would be very difficult to transition at this point, it’s just too low density. It was better 100 years ago than it is now.
Los Angeles is one of few US cities that is managing to build at least some new transit lines. Increasing density in desirable cities is actually pretty easy, all you have to is make it legal (by-right zoning) and then the market will do the immensely productive and profitable thing.
I find it interesting that at a certain time in Los Angeles, a segment of society could afford a craftsman cottage house, but not afford an automobile. This was the prime era of the Pacific Electric streetcar suburb, say around 1890-1920. Today, obviously, anyone who can afford a house anywhere in the country can afford an automobile.
The end of the Pacific Electric system was not a conspiracy theory by tire companies or anything like that; the price of the cars dropped and that's what consumers preferred, i.m.o.
Or Kansas City. Or St. Louis. Or Detroit. Or Chicago, even.
Pretty much any major American city is less dense than it was 100 years ago. It was cheaper to build out than it was to build up.
From an infrastructure perspective building out instead of up is incredibly expensive. Not just transport but also water, sewage, electricity and internet.
I should specify: it's more expensive for the developers and their home-buying customers to build up instead of out.
All of that stuff you listed comes from tax dollars, and people ultimately care less about that than what's coming out of their pockets for a home purchase. Well, until it's unsustainable, anyways.
Yes exactly. Building is cheap in the US relatively speaking. There are tons of grants and government money to help move things along. Those avenues don't really exist for maintaining things that were built with grants and outside funds. So we see TONS of expansion followed up with almost no maintenance and suburbs and less populated places literally cannot afford to maintain the services that they utilize. The burden is almost entirely shifted onto renters in urban areas instead.
In this country we have this ideal of a rugged individualist whose out there living off the land and making his own way. Never will this rugged individualist acknowledge that he's dependent on 10x as many miles of roads as his urban counterpart. Never will this rugged individualist acknowledge that providing him with internet access on the state's dollar costs orders of magnitude more than someone living in a sustainable location. Same with delivery costs and literally every other thing this person consumes. They get to pretend to be a self-reliant individualist while leaching off of the tax dollars of urban residents who cost a fraction of the amount to support.
> Never will this rugged individualist acknowledge that providing him with internet access on the state's dollar costs orders of magnitude more than someone living in a sustainable location
Thankfully we have Starlink to replace pork consumption with actual services.
Fires can solve that.
You’re right, but the thing that leads us to lighter EVs is solid state batteries.
Yeah, I’d expect EVs to get lighter over time as technology progresses. Car bloat is a much bigger problem. Totally insane that little practical city cars like the Honda Fit have gone practically extinct in the US in favor of bigger, heavier cars that don’t even necessarily bring improved cargo capacity for all that extra bulk.
I have a 2018 Fit and it's a fantastic car. It gets 36 MPG and has much more interior space than it would seem. I've had taller people ride in it comfortably and its crowning achievement was fitting a hot water heater in the cargo area with the rear seat split -- without having to remove the child car seat on the other side. Pair a roof rack and you really don't need more -- especially day-to-day.
It's a crying shame that they've stopped selling them in the US. Marketing (the real men need their Rams, thank you very much!) and the CAFE loophole seem to have won the day, though, and we're all worse off for it.
Marketing does seem to work, especially over generations. I think the main reason trucks/SUVs were marketed so much was because of a 25% tax on imported light trucks and not cars. The so called "chicken tax"[1] was imposed on light trucks in 1964 and is still with us today.
A big reason car companies push trucks so much is that they are more profitable per unit. Demand is extremely limited in terms of quantity, because you can only really sell about 1-2 cars per family, per about 10 years.
That means, all else being equal, a car company makes more profit selling a vehicle that has a higher profit margin. The $80k trucks my family members buy do not cost 3X as much to manufacture as say, a nice Camry, but the price you pay is about 3X. This means the dealer/manufacturer just outright make more money if a higher percentage of people buy trucks instead of small cars.
Consumers have "signaled" that they will be fine paying three times as much for the same exact feature set (no, they are not hauling anything, and there certainly isn't a massively higher percentage of Americans doing truck things than 50 years ago), even using longer term loans to make it happen.
When the car market has been basically saturated for decades, how else do you "make line go up" than selling the same product (transportation) for more money?
> The $80k trucks my family members buy do not cost 3X as much to manufacture as say, a nice Camry, but the price you pay is about 3X.
> ... even using longer term loans to make it happen.
I don't understand how so many people are driving these vehicles. Not only are they 2-3x as expensive to buy or lease but they're also 2-3x more expensive to fuel and maintain. (Probably to insure, too?) I don't have any data to back this up but my intuition tells me that these vehicles and their loans could be the cause of the next subprime mortgage-esque financial crisis.
It really is difficult to imagine a better vehicle for suburb/city usage than the Fit, unless you have a bunch of kids/people to move in which case I’d skip crossovers/SUVs entirely and go straight to minivans (which are also better than SUVs for most peoples’ needs).
Roads and road standards are a tragedy of the commons. People keep buying bigger cars and demanding more, wider lanes and parking spaces because they don't take any of the burden individually - it's the taxpayers as a whole that foot the bill.
Paradoxically most of the 'small government' types are often the biggest road users.
The solution to tragedies of the commons is to internalize externalities. Tax should scale with carbon use, congestion contribution, and microplastic emission.
> Paradoxically most of the 'small government' types are often the biggest road users.
I think it's "limited government". I'm pretty sure they would prefer roads get more spending.
> tire wear is proportional to vehicle weight to the fourth power.
Does this mean that a bus that weighs 10 times as much as a small car will produce 10000 times as much tire dust? If it does, I'm not sure if investing in buses will reduce tire dust at all. A bus can replace a lot of cars, but 10000 is a stretch. We need more trains.
I think the root observation here comes from https://en.wikipedia.org/wiki/Fourth_power_law which really talks about the inferred stress to the road for given weight on the axle, not tire wear based on vehicle weight. The above seems to be using a simplification based on passenger cars staying with 4 tires across 2 axles but how this relates to tire wear is going to be a bit more complicated when you start talking about vehicles which can have more axles, more tires per axle, and significantly larger tires.
I'd believe buses have a lot of tire wear compared to an individual car but I wouldn't use that relation as proof of just how many times so.
trams were popular in tons of places before, I understand they improved traffic significantly compared even to today, and they'd still have a positive effect now, I think. But most places shifted towards a car centric focus and we lost those.
Do you have a citation for the vehicle weight to the fourth figure? There is about a 2X variation in the weight of the vehicles I’ve owned, but even accounting for differences in tire size, I can’t come up with a 16x difference in how often I change the tires.
Thinking about it a different way, there isn’t much difference in recommended tire pressure among the autos I’ve owned. That means that the pressure between the road and the tire is relatively constant but the surface area of contact is directly proportional to vehicle weight. For a fixed contact pressure, I am struggling to imagine a physical process by which the rubber loss is not proportional to the contact area.
The fourth power law is usually applied to deformation of asphalt roadways (here's a citation for that: https://www.researchgate.net/profile/Maxwell-Lay/publication...); I haven't heard it applied to tires before. If I had to guess I'd agree with you - I would expect a smaller exponent, particularly if the tires are designed for the given load.
This Engineering Explained video seems pretty thorough. The short of it is that your intuition is in the right direction, its definitely not to the fourth power of weight. Vehicle weight does contribute to wear but according to Continental its less important than driving style and road curviness.
Most studies I've seen on this topic agree that the amount of pollution created is not linear, and this also makes intuitive sense. The heavier your vehicle, the wider and/or larger diameter your tires need to be to give it the required amount of grip. If those bigger tires wear out in the same time as your smaller vehicle tires, you've already created considerably more pollution.
I know this figure comes from road wear. I don't know if it applies to tire wear, and indeed I suspect it doesn't, if only because tires tend to scale with vehicle weight as you mentioned. I think road wear may be associated with structural cracking of the road which may not change significantly with tire area.
That says nothing about tire wear.
You think tire wear is less than road wear for a given load?
Yes.
Tire wear is caused by the surface of the tire being rubbed off through contact with the road. Most tire replacements happen because too much rubber has worn off of the contact surface.
While that happens some in the other direction, that’s not what usually causes road failure. You can tell this because pot-holes and other road failures have abrupt edges - they are not the road material until nothing is left but the earth beneath.
Roads also wear by being elastically deformed by the weight of the vehicles upon them. Eventually this deformation leads to failure of the road material, and it breaks away from the rest of the road, creating cracks and pot holes and so on.
Because the cause of failure is different, I don’t have any reason to expect the effect of vehicle weight to be the same. Moreover, unlike tire wear, its easy to hypothesize a physical reason that heavier vehicles will disproportionately wear the road: heavier vehicles will cause more deflection, and every material I have experience with will fail from repeated deflection faster if it’s deflected more.
Thanks, that was very helpful!
Also motorcycles/scooters. Unless you have children or live in a place with serious snow a motorcycle and a car sharing app/rentals for when you need to haul a sofa or something is a great combo.
Cheap, easy maintenance, good fuel economy and speed, traffic jam immunity..
I don't think this is entirely true but we need more research https://youtu.be/FcnuaM-xdHw?si=6bvFQdUjHi28CugV
None of these things are going to happen. Voters keep voting with their votes and their wallets that they want bigger cars and don't care about climate change. Meanwhile reactionary billionaires have hijacked most of our mass media as we blow by the 1.5°C Paris agreement and Trump dismantles our science institutions.
EV/hybrid only "zones" in Europe are crazy to me because the electric cars leech more tire carbon into the air anyway. Some regulation seems intelligent on the surface, but the devil is in the details.
Solid/particulate pollution from tires is definitely a problem, but in terms of carbon specifically isn't it many orders of magnitude less than the carbon from gas engines or electric power plants?
> These particles can include synthetic rubber, plastics, carbon black, and trace metals (like zinc)
you're correct. I mistakenly thought it was only carbon coming off the tires. So yeah, EVs have a significantly lower carbon output that ICE vehicles. My point still stands but thanks for the callout.
EV/hybrids also have regenerative brakes so emit less brake dust. Between emissions, tires, and brakes I'd be curious to see how it balances out.
But really cycling and transit are the way to go to make cities more liveable. Personal cars take too much space in a city and ruin the built environment for everyone not in one.
These zones are generally densely populated areas, and in Europe they usually have low speed limits, and roads design to encourage driving at low speeds.
To think that the minuscule difference in tire dust is significant at all, compared to the pollutants that EVs completely eliminates, is absolutely ridiculous.
The devil is in the details, yes. Have you considered that the policy makers have actually looked into the details? Have you looked into the details? Have you read any detailed reports about tire wear or did you just make up a problem based on your own intuition? Because I’ve seen reports from EV fleet operators that indicate that they see no difference in tire wear. Most likely the added weight (which isn’t all that much for modern, smaller EVs.. you know, the ones that people actually drive in urban/suburban areas in Europe) as a factor is drowned by other larger factors.
And we’re not that far away from EVs with the same or lower weight than their ICE counterparts, so getting these kinds of policies in place has some forward-looking aspects to them as well.
Excessive NO2 emissions spewed by diesel engines not meeting regulations very literally removed years from our collective life spans in city centres across the world.
Despite their own health hazards no amount of tire particulate from EV's can achieve that level of widespread public health impact.
How did the amount of brain microplastic manage to double between 2016 and 2025? The amount of cars hasn't changed that much.
Perhaps you're thinking our body is at equilibrium with the amount of plastic in our environment, but the reality may be that our body accumulates microplastics from the environment and they become concentrated over time. Kind of like how we can't get rid of heavy metals from our body, so eating lots of fish accumulates mercury to toxic levels. But eating fish is a conscious decision whereas microplastic exposure is an unavoidable fact of life now.
You can probably reduce microplastic consumption, but it is quite a pain and more expensive. Try buying everything at the store not wrapped/bottled in plastic. This does not even work as well as you might think as many things are wrapped in plastic and then presented as if they were not. For example, breakfast sausages in the meat display at my local Whole Foods are wrapped in paper when they give it to you, but come to the store in ~1lb plastic wrapped packages.
The hope is that the subjects in both samples have about the same age distribution. If they didn't, then the statistics are dubious.
The weight of the average car is steadily increasing though. SUVs, electrics, giant trucks, etc.
Perhaps the proportion of synthetic rubber (vs natural rubber) is increasing in tires?
User hammock, in this thread, may have suggested an answer.
Or one could just mandate that tires contain only biodegradable ingredients. That seems an inevitable step since wheel isn't going away no matter what the level of public transportation is. Some public transit, like busses and some subways, use rubber tires today.
Downvotes for suggesting biodegradable tires. What a site of wankers we have here.
Government could force car tyre companies to invest in developing plastic free tyre alternatives?
If there's no regulation then there's no will or urgency to waste money doing so.
Mass rail transit.
Didn't want to come off as too foamer ;)
Move away from big cities and high traffic areas in the meantime is my solution.
Doesn’t work. It’s in the rainwater. No rainwater on earth is safe to drink.
Does osmosis remove? Is it in all groundwater?
Because I have a well. A deep one. And an osmosis system.
6 months ago on HN "Boiling and filtering can remove microplastics from drinking water: study:
Do you consume drinks? Meat? Produce? All these things are chock full of their own micro plastics. It's unavoidable. We can probably reduce contamination but our children's children's children won't be free of it, not until organisms evolve to efficiently eat it. Then we'll have whole other sets of problems.
Do I consume drinks? No, except water and instant coffee, no soda, no beer. Meat? Yes in small quantities and much of it comes from the local environment. I grow most of my own produce, with RO water.
Yes they are unavoidable, just the plastic containers etc probably give some and I do eat candies and imported bananas and bread etc. But pretty sure I get a lot lower dose than most people.
However I'm not sure it matters that much until a mechanism of actual damage is established.
> I grow most of my own produce, with RO water
Do you really grow enough food to make up most of your diet on RO water? And is this specifically to avoid microplastic exposure, or what?
I grow around 1/3 of my own food. Yes all with RO water. I'd like to get above 50%.
Specifically produce, however we grow most of what we eat. We pressure can, dehydrate and ferment to preserve. I have background and decades of experience in growing, which is to say it's more than just standard hobby garden level.
The RO water is not to avoid microplastics (although that might a side benefit) but rather that the water is highly mineralized. It would be a long post to explain why I do this. Some is theoretical health concerns, some is more practical.
This is really interesting. Do you have suggestions how to use RO in garden scale? (Like link where could I start)
I built my own RO system it cost around $1500 including a water softener. There are some ongoing supplies every year, maybe $200 or less.
I don't have any links I just figured it out, but it's not super complicated. I made it out of undersink RO membrane housings (housings from those little RO systems you can buy for around $300 that do a couple of gallons a day). The membranes have pressure pumps in front of them that get it up to a couple hundred gallons RO water total a day.
Basic steps are 1) Soften the water, 2) Pass it through very tight filters (like 1 micron), I also carbon filter for organic contaminants, 3) Booster pumps put water through osmosis membranes and from there into a storage tank.
I just used plastic totes with gravel in the bottom to house the membranes and booster pumps.
I should write up a blog post on it one day because professionally installed osmosis can be expensive.
Thanks!
Interesting, thanks!
> However I'm not sure it matters that much until a mechanism of actual damage is established.
This is the thing about all the microplastics articles I see popping up: they rarely include any description of harm. If they even mention it, it is only speculative, as in this article. Until I read a scientific article about real harms, I am going to regard most of the microplastics news as fearmongering. Humanity has been surrounded by vast quantities of plastic for decades; if there was a big effect, wouldn’t we have seen it by now? If it has big effects, those effects would be surprising, which means that the evidence would have to be strong. I don’t see a lot of strong evidence.
If anyone reading this has a paper like this, please share.
There is no strong evidence of anything yet, but consider how long it took to "prove" to society's satisfaction that cigarettes are harmful, despite most scientists finding the lung cancer connection quite clear from pretty early. Comprehensive and long term data takes a long time. It could be worth it to be cautious in the meantime.
If microplastics are making our lives 10% worse in some dimension, we will have to stumble onto what that dimension would be basically by luck and then spend at least a decade rigorously studying it before we could make useful assertions.
The hubub about microplastics is that, we don't have great civilization wide health data on most health dimensions, so we don't even have good baselines to figure whether we have regressed in many ways. IF there is a negative effect, it will effect everyone all over the planet and there is no escape
It's an extreme corner of the likelihood/amount of harm graph, and some people think that corner of the graph warrants caution even before harm is proven.
It's the same situation we faced with leaded gasoline, and the US is pretty bad when it comes to those kinds of "mild, diffuse harm that mostly affects people who can't afford whatever system the wealthy use to avoid the harm" problems.
It's not fearmongering, we are literally gambling that microplastics have minimal harm right now.
That is perhaps the most insidious property of all when it comes to microplastics--it's incredibly difficult to work that out.
We don't have control groups, they're found in virtually every complex organism on Earth, including (best we can tell) all humans, so we can't form a control group. We've only recently really started to notice, care, or study them, so we don't have strong historical data to compare against. We don't have many isolated populations (especially of large enough size) where microplastic bioaccumulation is the only major difference in how their lives have changed in biologically relevant ways over the decades, so we can't effectively isolate the effects of microplastics from other confounding factors.
So you have these things that basically became completely ubiquitous--an unavoidable fact of not just human life, but all complex life on Earth--before anyone realized, with several other major global factors shifting concurrently. The end result is that, by the tools and methods with which we perform science, it's nearly impossible to study their exact effects. Maybe they're a slow-burning apocalypse subtly disrupting the mechanisms of life at their most fundamental levels and only getting worse with time, or maybe they do nothing or next to nothing like having a glass of sherry with your Sunday brunch once a week, or maybe they're somewhere in that vast, murky expanse in between the two extremes. Hell, there might even be a net benefit somehow. We just plain don't know, and don't know how we could know, so speculation is just about all we've got at present, and without knowing it's really hard to say if the messaging and literature surrounding the subject is aggressively over-alarmist or recklessly under-alarmist. The best we've really got is the simple fact that we notice them now, and thus have the chance to pay close attention, part of which is regularly taking basic measurements like these to try and correlate trends.
About all we do know is that they weren't here before, and "before" encompasses 99.9999% of all life that we know to have ever existed, so it's definitely weird and maybe probably bad.
There's definitely criticism to be had with the broader state of public health and science communication that harm, or at least the understanding that "we have literally no idea what the broader implications of this are but they're maybe probably not good", are considered to be implicit, either due to fallacious appeal to nature or the simple fact that alarmist headlines catch more attention, generating more traffic and revenue, and thus acceptance rates and grant money downstream. Which is, I think, the real core of the issue.
Nanofiltration or reverse osmosis will be most effective: https://www.epa.gov/sciencematters/reducing-pfas-drinking-wa... (save the site while the EPA still exists!)
I guess the polyamide filter in that system isn't putting microplastic particles in the water? Probably not.
Hope you never have to drive to the grocery store
Imagine a grocery store that is within a short walking distance, such that you don't need to haul a weeks worth of groceries but can get fresh food every single day.
US supermarkets are massive, take forever to buy small amounts of groceries, and even the walk to and from the car is long.
A better world is possible! (If better grocery stores constitute a "better world")
> you don't need to haul a weeks worth of groceries but can get fresh food every single day
I lived that life in my 20s
Turns out I don't actually want to go to the grocery store every day. I want to go once a week and stock up, which I can do thanks to inventions like the refrigerator and the automobile
no judgment on you in particular, but i’m not a fan of this thought process. I believe it’s a major cause for why americans (statistically) are so obese. and i say this as an american that lives in a city but has family in the suburbs.
running errands with your own two feet every day by walking, cycling, etc keeps people healthy and lean. this country has a major car problem. it’s sad.
of course one can go to the gym to stay lean and healthy, but that’s even more time consuming than stopping by the store for 5 minutes on the way home, and it requires extreme motivation. Hardly an improvement i’d say.
> running errands with your own two feet every day by walking, cycling, etc keeps people healthy and lean. this country has a major car problem
I did live this exact lifestyle in my 20s. I was definitely more active but my diet was way worse. I was closer to a lot of restaurants, and I was closer to a lot of bakeries and convenience stores and such as well.
A healthy lifestyle also requires a healthy diet and city living gave me far too much easy access to snacks and junk food. A lot of "it's only 5 minutes to go buy a snack". Daily stops for coffee that often included a pasty
Yeah, the walkable city does mean people are more active
It doesn't necessarily mean they are much more healthy. It still requires other forms of self control (which I admit, I struggled with)
thanks for the thoughtful reply. :)
I agree, it’s not a magic fix for all issues! But it does address one major component, the physical activity part. The other is diet, which is a separate issue of course.
And by that you mean drive to the gym, right? ;)one can go to the gym
I don't believe it. If you lived right next door to the grocery shop would you still only go once a week and stock up?
Nobody wants less flexibility, rigid plans and higher maintenance costs. I think what you really want is a big house with lots of space away from other people and since you can't have your cake and eat it too you've sacrificed everything else.
You got me
I actually did live in an apartment a block away from a grocery store and yes, you're right. I would not trade my current house for having a grocery store that close
Because living in apartments sucks
But even if I did live in my current house with a grocery store right next door, I still would prefer to go as few times a week as possible. Planning ahead and limiting how often I am at stores helps me tremendously with sticking to a budget, which is also something I place a lot of value on
When I lived close to a grocery store not only did I spend more because the prices were higher, I also made more frequent trips for things on a whim, like snacks and treats. It was a much more expensive lifestyle
Maybe other people don't have that same struggle with convenience, but I do. By making the barrier higher, my life is more affordable and I eat less junk food for sure
This is all just my experience though
> Because living in apartments sucks
This depends on a) what you want, and b) the apartment. If you want a garden, then an apartment is a non-starter, obviously. Also if you care about what the exterior of the building looks like that you'll want a house. But other than it doesn't make much difference.
The main difference for me is insulation from your neighbours. I've lived in good apartments and bad ones. The best ones you simply forget that you even have neighbours. The worst ones you can't forget because you can hear their conversations and them locking doors etc. The trouble is it's hard to tell what it's going to be like before you move in and this isn't the kind of thing that has standards or that anyone seems to think about. So for someone sensitive to noise, but also likes to make a lot of noise (I'm a musician), I'm resigned to living in a house too. But I'm not sure it has to be this way.
Well good news, nothing is stoping you from bringing home a full cartful of groceries that walking distance either. You just have more options.
Now, if you are really attached to your car and are only open to using your car for groceries, stay in suburbia, it's oversupplied through centralized planning and not at risk of going anywhere!
> Well good news, nothing is stoping you from bringing home a full cartful of groceries that walking distance either
Dunno about you but I only have two hands and can only carry so much at one time
I could have bought and brought a wagon or something I suppose, but that presents its own problems.
Where do I store the wagon in my tiny apartment?
What do I do with it when I'm actually in the store shopping, to make sure no one steals it while I'm in the store? I can't bring it into the store, it's too bulky for narrow urban grocery store aisles
How do I get my wagon full of groceries to my apartment, with no elevator?
Actually how do I get my empty wagon up to my apartment even, it's not going to manage narrow stairwells very easily even empty. So even if I leave it at the bottom and carry my groceries up by hand, I still have to get the wagon itself upstairs somehow
And then I also own a wagon that takes up my limited apartment space, which I only use to get groceries and provides no other utility for my life.
Unlike a car which I use all the time and only one of those uses is getting groceries
Have you never heard of a shopping caddy? https://en.wikipedia.org/wiki/Shopping_caddy
They're incredibly popular here, and yes, all supermarkets will have a lock stand near the checkout area so you can leave them there and easily reach for them as you're bagging your groceries. They're also foldable and/or small enough to fit in almost any closet.
Those little things would definitely not carry a weeks worth of groceries. They barely look like they carry more than I could by hand
Never seen a grocery store with a lock stand for these things either
They can hold a surprisingly big amount of cargo if you pack things right. Here in Spain they're definitely used for weekly hauls of groceries, although it might be pushing it if have more than two kids.
Not only that, but if you're close to a road at all, you'll intake the micro-plastics and nano-plastics.
So you really need to move away from roads. That's possible, but it's really hard to do in most developed nations. Just moving away from a city won't get you to where you need to be. Even when you get there, you have other issues. Like, food, energy, water/sewage treatment, etc.
I don't think people realize how difficult it would be to get away from this particular pollutant in our environment. I mean most of us don't own 500 acres in the Brazilian, Namibian, or Ghanaian countryside that we can retreat to. Even Brazil may be too far gone at this point to be honest. And Brazil is enormous. A lot of space. The number of tolerable nations that would have unaffected areas is decreasing fast. This really is a global problem.
ETA: Some remote parts of Canada and Alaska might fit the bill? Assuming you're not big on quality of life.
You can have really very good quality of life in remote areas. You just might die before you get help if you have a heart attack or something. But the rest of the time it's great!
15 minute cities is the answer.
My grocery store is literally in another town 20 miles away. I have an EV but apparently those are even worse for microplastic generation. Am I screwed?
An EV is objectively not worse for the environment. And virtually all vehicles contain large amounts of plastic (eg PVC). I recently heard model year 2024 vehicles are ~30% plastic by weight.
I’d wait until somebody can clearly state what the demonstrated harms of microplastics are before you conclude that there’s nothing you can do. An EV reduces emissions that we KNOW are bad, and over their lifetimes, the reduction is huge compared to an ICE vehicle. If you’re worried, though, walk or bike whenever you can.
Biking to grocery store is not an option for you, but you can still make a difference if you think about it. Eg, go to the store less frequently. Switch to a chest freezer for perishables. And so on. Draw up an energy budget and do the math.
There is a cost to human life, sure. But you can make it work if you really care enough. You are definitely not screwed.
I don't think you understand where I'm living.
"Microplastic Free", no, there is no such thing right now. But I'm very far from any major roads/interstates and hundreds of miles to any big city. I didn't move out here to avoid microplastics though, it just (maybe) turned out that way.
I'm actually not terribly afraid of microplastics at all, I just don't like urban environments.
Hope you never have to haul a family of 4 worth of groceries on a bus.
I do on a bike or walking weekly, it's not that crazy.
In a prewar US mid sized city, the density supports multiple grocery stores I can reach in about the same time as driving and finding parking.
Groceries. For a family of four (4). On a bicycle. Sure. How many times a day do you make the trip?
I make at least trip one trip a week. Why would I need to go every day?
I may stop by a store again during the week for a smaller trip if there's something I really need, or pop to a corner store if I need to grab something like drinks for guests, but it's not out of my way.
It's really not a big deal. Bike panniers can hold a ton.
What's so crazy about that? Never seen a bicycle with panniers and a basket? Or a cargo bicycle?
I've seen what a week's worth of groceries looks like for four people and short of a rickshaw you ain't getting all of that on a bicycle with or without panniers. I'm fairly certain the respondent is coyly ignoring the headcount requirement in my original sneer.
>I've seen what a week's worth of groceries looks like for four people
>short of a rickshaw you ain't getting all of that on a bicycle with or without panniers
Four Americans, maybe.
Pfft. 56,000 calories doesn't pack but so dense unless you're routinely feeding your family pemmican.
Trivial if you leave near a grocery store. If you live in most US cities, much more the suburbs, then being dependent on your vehicle to do literally anything is part of the problem. In very few places in the US can you choose to do otherwise.
I love breathing brake dust too!
What percentage is that?
Perfect, I was hoping to increase my neuroplasticity.
I recognize and acknowledge your humorous post.
It totally struck my funny bone. It was very humerus.
Doctors HATE this one trick! Click here to find out!
Nice.
I like the analogy where other articles have said we have microplastics in our brain about the size of a credit card (which generally weigh between 4g and 10g) better.
Saying a “spoon’s worth” seems to be downplaying the unmitigated potential risk. We have no idea what will happen as we (and all the other creatures on earth) keep storing more and more microplastics in our organs.
Nobody is going to stop driving. Car tires are the largest source of microplastics.
(actually I don’t drive though so who am I to judge)
> unmitigated potential risk
The risk does seem fairly mitigated, most of us will make it through today fine. The only part of my brain I can account for now is the 1x credit card worth of plastic, all the other bits are a mystery. Death was inevitable before the microplastics, remains inevitable after the microplastics and things seem fine so far.
We don't know much about the risks of anything. People regularly douse themselves with mind-altering substances and ingest the weirdest variety of stuff.
Shortening your period of observation so that the effects have not occurred yet does not mean it’s “mitigated”.
And your philosophy of your own mortality is just as reductive, because humans have been trying to survive since time immemorial and do not actively work on their deaths unless in an unhealthy mental state.
Seems like a more important problem, then, the part where people inevitably die. I mean compared to having some plastic in their heads.
I mean, what are we really going to do about it? So much chaos in the world, I don't think many are focusing on keeping plastics out of our body. No one's championing it.
> The risk does seem fairly mitigated, most of us will make it through today fine.
This is an incorrect usage of the word "mitigate." To mitigate means to lessen the risk. Mitigation requires action.
I suspect you mean that the risks are "overstated."
I barely think the risks have been stated at all. They found a correlation between high levels of microplastics in the brain and dementia. There is a correlation between a bunch of things and dementia. I expect there is a correlation between good health and dementia, unhealthy people would tend to die off young without the time to fall apart mentally.
Would be nice if just once these sorts of things could have beneficial effects.
Like the ship-produced aerosols that seeded clouds, increased albedo, and cooled the planet, in what James Hansen has called a "Faustian bargain". We successfully stopped that with regulations.
Not to mention that all spoons are different. I always get confused about “half a spoon”. Is it half of a “pile” or there must be half of its surface visible from above, while the subject matter is flat in the spoon (i.e. the lateral projection shows only the spoon). And should you account for the pile slope in case of bulk materials? And then when you figure that out, your spoon may be anywhere 0.5-1.5x in size/depth than someone else’s. It may be literally 3x times more or less. But even that is still less inexact than measurement extrapolation methods that the article uses, according to the top commenter.
I was trying to figure out from the headline if they meant enough microplastics to fill the bowl of a spoon or microplastics equivalent to a plastic spoon. I don't know why everyone is allergic to weights and measures.
If they're going for shock value they should use something more sinister than a spoon. Like enough plastic to make a little decorative Halloween spider. People would be more frightened by a spider than a spoonful of plastic.
> Nobody is going to stop driving. Car tires are the largest source of microplastics.
many already have, bicycles and public transport ftw
There's realistically fewer than twenty metro areas in the US where the majority of commuters could rely solely on biking and public transit for everything. Twenty might be generous, even.
That may be true, but you don’t have to rely on biking for “everything.” Some biking is better than no biking.
I live in a small college town a couple of miles from the college. I walk, run, or bike to work nearly every day. But I am not a purist about it. We have a snowstorm forecast for tomorrow so I am going to drive (my EV). Would it be better for the environment if I walked? Probably? Does one trip really make that much of a difference though? Probably not.
I think there are likely many many places where people can walk or bike to some of the things if not all of the things. People really should do that more (not the least reason because biking is wonderful). Biking to the grocery store is mostly impractical for me as it is many miles away. But that’s ok! I am doing other things.
Since the pandemic passenger car miles, airline miles are back at pre-pandemic levels.
Transit use is at 80% of pre-pandemic levels.
https://ti.org/antiplanner/?p=22722
Farebox recovery ratios have consequently become even worse.
The new US government is also presumably not going to fund much transit expansion.
It'd be interesting to see if more people work from home on a given day than use mass transit to get to work.
It's also pretty similar in Australia at least and probably in more places around the world.
There is a positive spin on this: the majority of Americans already live in or near dense urban centers. If we had solid public transportation only within these centers and to adjacent suburbs we would eliminate most car trips. That's bot much physical area to cover.
Depends on what you consider "in or near".
I live "in" a major American city. Well, a reasonably major Midwestern city. It's roughly a third the size of Rhode Island. It has half a million people in it.
Unfortunately a bicyclist on the road will be exposed to far more tire microplastics than drivers in their enclosed cabins with filtered and recirculated air.
still rubber so still microplastics?
Less!
To me, the spoon sounds scarier. But I don't think there's a right answer to how scary a new phenomenon should be made to sound. You want it to sound scarier, this thing we don't know much about? Won't that happen naturally since everybody's ready to be scared of news anyway? Is it being downplayed? Relative to what, hunches? The information should be presented dispassionately, but engagingly, and that is an impossible combination, so it what we'll actually get is always something with the wrong overtones.
> not a spoonful, but the same weight as a plastic spoon
oh
- There is a horrifying 512-ounce version that they call Child size. How is this a Child-sized soda?
- Well, it's roughly the size of a two-year old child, if the child were liquefied.
That's both a misleading headline and a really odd unit of measurement. So odd that I wouldn't be surprised if the US adopted it as the official unit of measurement of microplastics (I kid, as an American).
How many Bald Eagle Per Football Fields would that amount to?
I find this hilarious. Why would they choose such a misleading unit
Isn't it about the same?
How big is a spoon, anyway?
do we need a unit conversion for how many spoonfuls of plastic are in a plastic spoon?? seems like it might be important for this article.
Well article says a teaspoon has 7g mass, and just spitballin here but I'd say a plastic spoon has about 1g/cm^3 density. And there are 4.83cm^3 in a teaspoon. So I guess in fact there are 1.44 teaspoons of teaspoon in the brain. Or would that be 1.44 tsp^2...?
But I'm an American and I have at least 3 imperial teaspoons of microplastic in my brain or gosh darnit I'm 2 bald eagles short of a touch down. If you know what I'm sayin.[1]
That's not great
So more
As I understand it, they took a small sample of brain tissue, extracted the plastic, and then extrapolated that (based on the tissue sample size) over the whole of the brain.
This assumes the presence of plastic is evenly distributed throughout the brain, which isn't necessarily the case.
I would think that we would be seeing a lit more issues if we had that much plastic just in our brain. But maybe our body doesn’t mind all that much. I guess we will see how things play out in another 30 years though.
Huberman Labs has been mentioning plastics in the body frequently.
Don't laugh, but I'm getting a new toothbrush to be safe.
This is one of those headlines that smells like nonsense before even reading the article (doesn't mean it is nonsense, but the quantity advertised seems implausible).
I am hoping that they discover that polyethylene is a natural component of brain chemistry.
What about polystyrene, polyvinyl chloride, et. al?
Really regretting chewing on all of those straws as a kid, eating hot food out of all of those takeout trays, keeping my car windows open, living near roads… and…
I rode a hard plastic bike seat on my bmx to school and back everyday. eyes emoji. my kids i shoot out will be g.i. joe figurines
The only good news here is that it's possible that the body can clear the plastics. This is from the linked study:
> While we suspected that MNPs might accumulate in the body over a lifespan, the lack of correlation between total plastics and decedent age (P = 0.87 for brain data) does not support this (Supplementary Fig. 1). However, total mass concentration of plastics in the brains analyzed in this study increased by approximately 50% in the past 8 years. Thus, we postulate that the exponentially increasing environmental concentrations of MNPs2,14 may analogously increase internal maximal concentrations. Although there are few studies to draw on yet performed in mammals, in zebrafish exposed to constant concentrations, nanoplastic uptake increased to a stable plateau and cleared after exposure15; however, the maximal internal concentrations were increased proportionately with higher nanoplastic exposure concentrations. While clearance rates and elimination routes of MNPs from the brain remain uncharacterized, it is possible that an equilibrium—albeit variable between people—might occur between exposure, uptake and clearance, with environmental exposure concentrations ultimately determining the internal body burden.
Which means that if we were to take action on this, we might actually be able to reduce our exposure. Unfortunately, things are going in the wrong direction.
I keep thinking it would be nice if microplastic exposure were to start generating the kind of focus and controversy that is currently taking place with vaccines and autism spectrum disorder.
My understanding is the best thing you can be doing along with reducing exposure is regular blood donation
Interesting. My father has received a ton of donor blood over the past few years. Once he's gone I'll be donating regularly. My father's alive because dozens of people donated.
To anyone here that has made a deposit to the blood bank: we thank you.
blood bank CEO thanks you too because the make millions selling your blood
Go away. Just go away. Sometimes too much cynicism is toxic.
Donating blood is good for other people regardless of the profit motive from the company.
And if you're talking about the Red Cross, their CEO is reported to make less than 700k/year.
That's not bad for running one of the largest medical non-profits in the world.
Cool, what was I gonna do with it? Unless we're selling to Dracula, owning external blood is highly regulated. So anyone buying has some credentials to use it.
So what you’re saying is that leeches as medicine are coming back.
Pass the microplastics along to some other sucker, a cunning plan.
dilution is the solution to the pollution
So bloodletting?
>>environmental exposure concentrations ultimately determining the internal body burden.
As another commenter asked "How did the amount of brain microplastic manage to double between 2016 and 2025?" It is doubtful that the environmental concentration level doubled during this time.
I think this is a conversion error. According to the ABC story about this the brain has 4800 micrograms of microplastics. That's alarming, but that is 4.8mg, which is .0048 grams. A plastic spoon is over 4g. They mixed up micro and milli and were off 1000x. ABC news: https://abcnews.go.com/Health/brain-tissue-higher-amounts-mi... Original study: https://www.nature.com/articles/s41591-024-03453-1
I must have some of that microplastic in my brain since I misread the start of the title as "Human, Brian May, ..." and then couldn't parse the rest properly.
Pre-print paper that concludes “may”, so by implication, also “may not”.
And also may, or may not, be harmful.
Sounds like methodological error. Like your black spatulas. Somewhere they’ve divided by zero, clamped, and averaged or something dumb like that.
I thought it was our gonads that had the most?
This statement isn't necessarily at odds with that one.
Well, Vonnegut was right. It's just a dog's breakfast.
why did not they got flushed by our digestive system,yes micro plastics are tiny,still they are too large to get into arteries and veins thus no way to reach the brain?
Nanoplastics can be so small that they can get inside most cells even blood cell so could pass through gut lining and blood brain barrier and sometimes are shaped like the key/lock our body already uses for certain intracellular chemical interactions and interferes with the correct molecules doing work, so they can be both inert for the most part and harmful because our cells just don’t just eject them automatically - though there also appears to be some max amount based on exposure level. The vast majority we might eat is excreted in bowel movements and urine and it still accumulates in tissue due to ubiquity. article for laypeople https://www.npr.org/sections/shots-health-news/2024/12/18/nx...
Great to know the insights! It seems inevitable though as plastics are everywhere.
Is there no molecule that could be designed which would break down microplastics throughout the body, without harming biological materials? Or even just the blood stream?
I’m not a chemist, but it seems like if this can be done it would be huge.
Even if you could invent it, I don’t think there would be demand for it (yet)
Does it have a negative effect on us though?
I mean, assuming I do have a spoon's worth of microplastics in my brain, I don't notice any impairment.
I write JavaScript just fine.
Cool. Now how much sand is in your brain? Equivalent of two glass spoons? Sand dust is way more abundant than plastic and similarly inert.
You're being downvoted, but I think it's a really good question.
We eat and breathe all sorts of stuff that comes in nano-sized particles. We've been inhaling smoke from cooking fire, eating plant matter crushed between rocks rubbing against each other, drinking water with dissolved bits of all sorts of things, and so forth for many millenia now.
The body seems to have mechanisms to clear most of this stuff out of us over time, no? Isn't our body chock-full of waste products from our cells that are constantly getting flushed out? Is there any reason to think that nanoplastics would be different?
Or plant fiber. You eat enormous amounts of this stuff that you can't break down.
Depends on where the sand is. I don't want that stuff in my lungs.
Lungs have been dealing with sand dust since there were lungs, have they not?
Honest science on a foreign material in the brain or body should be able to present a baseline amount of total foreign material for comparison.
If our environment is now 10% microplastics, then 10% of the foreign material found in the brain being microplastics would be normal.
Such an easy point, and yet the parent posters dont get it...
just a spoon full of plastic helps the medicine go down the medicine go down the......
Imagine if microplastics in the brain could somehow be utilized by neurons for really long term memory storage or something.
No
Nonsense article, you could fit way more than that.
baity headlines that scare the shit out of you, exactly what I’m NOT looking for on HN
So are we okay with this? We don’t want to hurt industries or the market so we should accept this, right? I think it’s extremely important that Nestle and Coca Cola continue to be successful. I certainly don’t mind eating plastic if it means the market does well.
Okay I’m sorry for the snark but when these articles come up some are like “the studies are inconclusive of the effects” but I’m just like “there’s plastic in your brain!”