Microplastics in the human brain

https://www.smithsonianmag.com/smart-news/the-human-brain-may-contain-as-much-as-a-spoons-worth-of-microplastics-new-research-suggests-180985995/

by headclone • 1 year ago

245 201 1 year ago

smithsonianmag.com

bhaney• 1 year ago

not a spoonful, but the same weight as a plastic spoon

SecretDreams• 1 year ago

That's not great

silisili• 1 year ago

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).

ryandrake• 1 year ago

How many Bald Eagle Per Football Fields would that amount to?

smnrchrds• 1 year ago

- 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.

mindwok• 1 year ago

I find this hilarious. Why would they choose such a misleading unit

card_zero6• 1 year ago

Isn't it about the same?

How big is a spoon, anyway?

upghost• 1 year ago

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]

[1] https://news.ycombinator.com/item?id=42958104

TZubiri3• 1 year ago

So more

chiefalchemist2• 1 year ago

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.

robocat• 1 year ago

I am hoping that they discover that polyethylene is a natural component of brain chemistry.

jondwillis2• 1 year ago

What about polystyrene, polyvinyl chloride, et. al?

medellin• 1 year ago

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.

chiefalchemist2• 1 year ago

Huberman Labs has been mentioning plastics in the body frequently.

Don't laugh, but I'm getting a new toothbrush to be safe.

mythrwy7• 1 year ago

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).

megamike• 1 year ago

just a spoon full of plastic helps the medicine go down the medicine go down the......

koolala• 1 year ago

I thought it was our gonads that had the most?

jdiff• 1 year ago

This statement isn't necessarily at odds with that one.

shironandonon_2• 1 year ago

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)

roenxi2• 1 year ago

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.

rTX5CMRXIfFG• 1 year ago

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.

SmirkingRevenge• 1 year ago

Would be nice if just once these sorts of things could have beneficial effects.

itishappy• 1 year ago

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."

tcfhgj2• 1 year ago

Nobody is going to stop driving. Car tires are the largest source of microplastics.

many already have, bicycles and public transport ftw

lenerdenator4• 1 year ago

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.

knowitnone3• 1 year ago

still rubber so still microplastics?

pants2• 1 year ago

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.

card_zero6• 1 year ago

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.

wruza• 1 year ago

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.

plagiarist• 1 year ago

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.

adriand• 1 year ago

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.

russdill• 1 year ago

My understanding is the best thing you can be doing along with reducing exposure is regular blood donation

ericd• 1 year ago

So what you’re saying is that leeches as medicine are coming back.

lemonberry• 1 year ago

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.

throwaway6576562• 1 year ago

dilution is the solution to the pollution

card_zero6• 1 year ago

Pass the microplastics along to some other sucker, a cunning plan.

TZubiri3• 1 year ago

So bloodletting?

throwaway6576562• 1 year ago

>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.

mreid• 1 year ago

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.

scotty79• 1 year ago

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.

kijin2• 1 year ago

Depends on where the sand is. I don't want that stuff in my lungs.

pulvinar• 1 year ago

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.

pfdietz• 1 year ago

Or plant fiber. You eat enormous amounts of this stuff that you can't break down.

crazygringo• 1 year ago

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?

Kapura2• 1 year ago

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.

mythrwy7• 1 year ago

Move away from big cities and high traffic areas in the meantime is my solution.

dymk• 1 year ago

Hope you never have to drive to the grocery store

shironandonon_2• 1 year ago

Doesn’t work. It’s in the rainwater. No rainwater on earth is safe to drink.

https://www.bbc.com/news/science-environment-62391069

hammock• 1 year ago

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

kijin2• 1 year ago

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.

ethagnawl3• 1 year ago

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.

penjelly3• 1 year ago

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.

joseangel_sc• 1 year ago

I don't think this is entirely true but we need more research https://youtu.be/FcnuaM-xdHw?si=6bvFQdUjHi28CugV

repiret3• 1 year ago

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.

twelvechairs• 1 year ago

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.

guelo• 1 year ago

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.

Lanolderen• 1 year ago

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..

throwaway815232• 1 year ago

How did the amount of brain microplastic manage to double between 2016 and 2025? The amount of cars hasn't changed that much.

JKCalhoun• 1 year ago

User hammock, in this thread, may have suggested an answer.

markerz• 1 year ago

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.

meindnoch2• 1 year ago

The weight of the average car is steadily increasing though. SUVs, electrics, giant trucks, etc.

o_nate• 1 year ago

Perhaps the proportion of synthetic rubber (vs natural rubber) is increasing in tires?

newsclues2• 1 year ago

I love breathing brake dust too!

7e2• 1 year ago

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.

7e2• 1 year ago

Downvotes for suggesting biodegradable tires. What a site of wankers we have here.

CommanderData• 1 year ago

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.

meindnoch2• 1 year ago

Mass rail transit.

Kapura2• 1 year ago

Didn't want to come off as too foamer ;)

niceice• 1 year ago

What percentage is that?

timr5• 1 year ago

This 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."

rthomas6• 1 year ago

Well, it still tells us something. What are the upper and lower bounds of whole brain microplastic content, given that 25% variation?

timr5• 1 year ago

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.

userbinator• 1 year ago

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

timr5• 1 year ago

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.

jondwillis2• 1 year ago

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…

_sys49152• 1 year ago

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

odyssey7• 1 year ago

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.

ed_mercer• 1 year ago

Even if you could invent it, I don’t think there would be demand for it (yet)

deadbabe• 1 year ago

Imagine if microplastics in the brain could somehow be utilized by neurons for really long term memory storage or something.

TZubiri3• 1 year ago

SV_BubbleTime• 1 year ago

Nonsense article, you could fit way more than that.

mondobe• 1 year ago

Perfect, I was hoping to increase my neuroplasticity.

knowitnone3• 1 year ago

I recognize and acknowledge your humorous post.

Sparkyte• 1 year ago

It totally struck my funny bone. It was very humerus.

HaZeust• 1 year ago

Nice.

nusl• 1 year ago

Doctors HATE this one trick! Click here to find out!

booleandilemma• 1 year ago

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.

latentcall• 1 year ago

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!”

yapyap• 1 year ago

baity headlines that scare the shit out of you, exactly what I’m NOT looking for on HN

synergy202• 1 year ago

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?

stevenwoo• 1 year ago

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...

synergy202• 1 year ago

Great to know the insights! It seems inevitable though as plastics are everywhere.

kaiwen1• 1 year ago

Pre-print paper that concludes “may”, so by implication, also “may not”.

And also may, or may not, be harmful.

renewiltord• 1 year ago

Sounds like methodological error. Like your black spatulas. Somewhere they’ve divided by zero, clamped, and averaged or something dumb like that.

purplezooey• 1 year ago

Well, Vonnegut was right. It's just a dog's breakfast.

alana314• 1 year ago

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

Microplastics in the human brain

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