Bioaccumulation of Microplastics in Decedent Human Brains
ncbi.nlm.nih.gov
ncbi.nlm.nih.gov
The only good news is that apparently the brain can clear these particles; the problem is that there is a steadily increasing amount of exposure which means that rather than clearance, there is accumulation.
Easy on the hyperbole. Let's assume that this study is correct, and everyone at median age of 50 is walking around with this level of microplastics in the stated organs. Are we all dead? Disabled? Dying? No. Our lifespans are amongst the longest in human history. I'm doing OK. How about you?
Far bigger practical concerns are that we're fat and lethargic and suffering from metabolic disease, heart disease, cancer and diabetes en masse because we eat too much. About the only thing you can do with this finding is wave your hands around and make hypothetical links to this and that (as they do in the paper), or try to claim that this is really, secretly the underlying cause of the stuff that is actually, observably killing us.
I'm not saying there's no concern here, but I am not "terrified" of this. I am actually scared of getting fat, or falling down when I get old from being weak. These are things that happen to nearly all of us.
Anyway, first rule of science: when we look for things, we find things. If you are "terrified" by everything new you find, you are applying an emotional judgment to what you see, and not being objective enough.
Personal choices go a long way, here. Exclusively use glass and metal cookware, utensils, food containers, and straws. Don't paint your fingernails, or if you do, don't chew your nails. Don't eat fast food, takeout, or DoorDash, be selective about your restaurants (tour the kitchen if you can). Wash your vegetables. Buy from butchers that wrap in non-plasticized paper. Don't live in cities with poor air quality. Replace StainMaster carpets with ceramic tile. Don't eat large predatory fish like tuna, (avoid large predatory animals in general, as they are metals and plastics concentration machines). Buy bottled water in glass only, or filter your own.
Can you reduce your intake to zero? No, but you can get pretty close.
Until you can figure out how to stop breathing and drinking, you have microplastics in your body. In fact there's no organisms left on Earth without microplastics in their body. Which is why everyone is making a fuss. If this does turn out to be a problem, we're kind of fucked.
This kind of "terror" is usually little more than a backdoor way for someone to advance their low-evidence "science" agenda:
"I'm scared of X, therefore all of you must worry about it too, and that means stop doing/using X, and/or do exactly what I say to minimize the impact of X."
I'm not saying you have to do anything. I'm saying that microplastics are prolific, and we don't understand the effects. That's just reality.
Personally, I believe on a political scale we should be reducing our plastic consumption. Because it creates far too much waste.
You'll note that I never said that we shouldn't do more research. You'll also note that sibling comment (agreeing with you) is calling for regulation and government action. So maybe you are just calling for research, but...
> Push for better understanding and maybe regulations to help reduce the impact. Again, with getting fat I have agency over. It's on me to do it. With microplastics, government action is needed, so we need to be better informed and press government to act on our interest.
> What, exactly, would you have the rest of us do, other than panic?
Push for better understanding and maybe regulations to help reduce the impact. Again, with getting fat I have agency over. It's on me to do it. With microplastics, government action is needed, so we need to be better informed and press government to act on our interest.
Advocate for a reduction in plastic manufacturing, consumption and waste. It's pretty straightforward. We did it with lead. I acknowledge that there are certain things that we make with plastic that modern society requires to function. For the rest, if we cannot manage to figure out how to keep this stuff out of our bodies and brains, then we should be replacing it with alternatives.
The part about this study that I personally find terrifying is the trajectory. A 50% increase in 8 years is astonishing. Without more data points we don't know what curve we are on right now (logarithmic? exponential?) but is this an experiment we really want to be running on our brains? I can tell you that this experiment participant wants to opt out immediately.
We are talking about bioaccumulation of an environmental pollutant in critical human organs here. The precautionary principle would seem to apply.
Well, thanks for being explicit about it, I guess.
> We did it with lead.
Yeah, you skipped a step: we know that lead is toxic. It's not an unproven hypothesis.
> The part about this study that I personally find terrifying is the trajectory. A 50% increase in 8 years is astonishing.
I mean...maybe? The methodology is pretty uncalibrated, the demographics of the groups is completely unknown, and the ug/g estimates they're making don't pass a common sense test. Far more likely that you can't read anything into the time-series comparisons.
Still not terrified.
It is my job (all scientists' jobs) to call out panic based on "science". More generally, the people who want you to believe that X hurts you (for whatever value of X) need to bring solid evidence, not just unproven hypotheses.
I don't really care about plastics, fertility or fœtus so I won't pretend I do, but if you do, maybe look into it?
Not getting fat is easy, avoiding microplastics is not. One problem affects people with a certain lifestyle, the other affects everyone (it's an environmental issue).
Also, as the article points out, the amount of microplastics accumulated in living organisms is still rising. It's something that needs more attention.
The notion that scientists can or should be emotionless, and that this somehow produces 'objectivity', should really be consigned to the history books. Expectation and promotion of emotional detachment leads to burn out, anxiety, unrealistic expectations, unsupportive working environments, poor judgement, dehumanising of experimental subjects, etc etc etc. See the majority medical and psychiatric science history.
I'd far prefer different terminology. Maybe 'calm' or similar. Expecting and encouraging scientists to be calm is more realistic and achievable, and doesn't deny the fundamental reality that much of human existence has an emotional component.
Panicking over microplastics in human brains is surely an entirely understandable reaction. Rather than criticising it, we can learn from it. I want my healthcare researchers to be calm but strongly motivated.
The problem with poisons is that we view them in a binary way. They're either bad, or they're not. They either hurt you, or they don't.
But in reality it doesn't always work this way. There's infinite levels of bad.
Eating off a lead plate, as the greeks did, is poisonous but certainty not deadly. Nobody was disabled.
Instead, the rich just slowly went insane over the course of their lives. Across decades, their mental state deteriorated as they grew mad. For their society, impossible to perceive. Too slow, too widespread.
Obviously we don't know the extent or even if there is anything bad about microplastics. But if there were, would we even be able to tell by the time we get there? Or would that just become life?
The point is: without evidence that "the poison" is actually toxic, and certainly without evidence that it's more toxic than anything else you're regularly doing, then you're effectively just fretting. In the case of microplastics, we basically have neither. We have some weak lines of evidence of minor harm in other animals, and lots and lots of theories about what might happen.
Note that I didn't say "don't worry about it". I just said "don't be terrified".
Personally I feel like the environmental contamination is the problem. Let's say we do workout this is causing some type of health issue, that's it , there is no way to fix this. We've contaminated everything with microplastics and there's little doubt , if we keep doing it, it WILL cause major issues, at least for the ecosystem, which we do rely on and that will have negative effects for us.
If as you claim the brain can clear out these particles, why is it terrifying? I have been asking for why microplastics are harmful and gotten a lot of great ideas but almost no studies or evidence. I guess we need to start researching the causal effects of MPs and not just how much MPs there are everywhere.
Brains were 0.5% plastic by weight? The highest value was nearly 1% plastic.
That seems hard to believe.
How is it even getting to the brain- isn’t there a blood brain barrier that even pathogens have a hard time getting through?
When you're saying "about" and then cubing the number you can have a pretty significant difference.
In any case, comparing it to a solid ball isn't so useful. Even the idea of "density" for something that is dispersed as small particles isn't too useful; proportion of mass is really the only useful metric.
> Micro- and Nanoplastics Breach the Blood–Brain Barrier (BBB): Biomolecular Corona’s Role Revealed
> The blood–brain barrier (BBB) is an important biological barrier that protects the brain from harmful substances. In our study we performed short term uptake studies in mice with orally administered polystyrene micro-/nanoparticles (9.55 µm, 1.14 µm, 0.293 µm). We show that nanometer sized particles—but not bigger particles—reach the brain within only 2 h after gavage. To understand the transport mechanism, we performed coarse-grained molecular dynamics simulations on the interaction of DOPC bilayers with a polystyrene nanoparticle in the presence and absence of various coronae. We found that the composition of the biomolecular corona surrounding the plastic particles was critical for passage through the BBB. Cholesterol molecules enhanced the uptake of these contaminants into the membrane of the BBB, whereas the protein model inhibited it.
The sensitivity of the GC/MS method makes me hypothesize that the stated values are massively inflated. Whatever error there was in that original measurement is probably amplified like crazy in scaling up to ug/g estimates.
It’s not like corporations are taking plastics out into the wilderness just for fun.
I would say a relevant part of them comes from individuals. If you believe the issue is important enough, then raising awareness is the right direction so they take healthier choices. However most of the worlds population lives in developing countries, and microplastics are very low in their list of priorities, their top priority is actually making to the end of the month with enough food, shelter and some medical care or even education for them or their kids.
Blaming everything on greedy corporations is a very superficial analysis.
This is why we, as a population, won't agree to curb CO2 sufficiently to address climate change but instead will simply adjust and, maybe eventually, accept geoengineering based approaches. That said, the next 10 years will be telling in how conservatives react to much higher home owner's insurance premiums...
https://www.newsweek.com/microplastic-map-reveals-countries-...
> When it comes to microplastic inhalation, Mongolia and China came in joint first place, with citizens of both countries inhaling more than 2.8 million microplastic particles a month. The United Kingdom came in third place, in joint place with Ireland, inhaling 791,500 particles per month. By comparison, the U.S. came in near the bottom of this list, in position 104 out of the 109 countries assessed, with only 10,500 microplastic particles inhaled per month.
Which country has the biggest stock market? US https://www.statista.com/statistics/710680/global-stock-mark...
Which country comes near last in inhalable microplastics: US
So you should be thanking shareholders if you live in the US (most are probably voters too!).
Ask your representatives today to ban all goods using China’s supply chain, and start producing all your country’s needs in your own soil.
Then measure the inhalable microplastics stats, that way we can know for sure if your country’s “environmental protection” is viable or just an excuse to offload dirty work to developing countries.
Remember the US is second in manufacturing next to China.
https://www.brookings.edu/articles/global-manufacturing-scor....
Why isn’t the US as polluted then?
Cyanide will kill you. Almonds have trace amounts of cyanide. You can eat almonds till you get sick, but that tiny amount of cyanide won't kill you. The dose makes the poison. On the other hand, those fancy car-fentanyl, if a flake touches your skin, you'll od and die. It's super super toxic.
One flake of microplastics in your body isn't going to do anything.
Now,
> although recent studies associated MNP [micro- and nanoplastic] presence in carotid atheromas with increased inflammation and risk of future adverse cardiovascular events
It's not like every muscle fires on every heartbeat. They try, but some are old or dead. There are a lot of them, all working together. And they're constantly repairing or regrowing new muscle cells. How does the heart shed microplastic? Can it? How much till the immune system kicks in and starts causing inflammation? Inflammation is generally good, but super dangerous in the heart. Too much inflammation, and well, it stops firing correctly.
> what is not clearly understood is the internal dose in humans.
How much microplastic is too much? nobody knows. Seems like, you get too much, and repair systems start kicking in. The repair systems can't actually fix anything, but make you weak/sick, and you're generally worse off. When some other thing shocks the system, your body is already in panic mode, so the "normal" response of panicking doesn't change anything. Odds are, you just die.
Also, why are you trying to deliver a point without looking up most of the examples I've listed? Do you expect that to be a convincing argument?
Consider also that some pollutants accumulate in the food chain, impacting future generations, for an indefinite time. Such as mercury in seafood.
Do you think the problem will go away over time? Are you OK with having fewer things that you can eat without poisoning yourself? Do you realize we only have so many reservoirs from which calories can come from?
Take care where your rice is grown.
Ultraprocessed foods are already poison and most of us, probably including you, are consuming them regularly. Are you OK with that? And what is this talk about caloric reservoirs? Humans 8000 years ago had far fewer options and they still survived long enough to pass cultural lineages down to us. Most of your "caloric reservoirs" did not exist before the 20th century because the science and industry that created them did not exist.
It's not like we'll be able to just outlaw it and be done with the issue after a few years. So for this specific polluant, it feels right that we should be cautious and look for solutions as quickly as we can.
Ultra processed foods are a problem and likely contributing to the plastic problem. I do what I can to reduce my reliance on both. Yet the solution won't be the few educated among us stopping ourselves. It must be regulated collectively or we'll remain in a prisoners dilemma as the pollutants accumulate.
Primarily, I _am_interested with health outcomes within my and my children's lifespan so that's the sort of time span I'm primarily concerned about. If the comparison to asbestos hold's true then we still have a _long_ time (long enough that any potential deleterious effects will be felt by all currently living and soon to be living members of my family) before any sort of regulatory action will be taken regardless of the health impacts.
> Also, why are you trying to deliver a point without looking up most of the examples I've listed? Do you expect that to be a convincing argument?
Because I'm _not_ your fact-checker. You're other examples may well follow a much quicker time-frame between discovery and strong regulatory action; I don't really care one way or the other, since at least one example shows a course of history which would play out poorly for those of us alive _now_ and exposed to increasing levels of environmental plastics.
I suspected mass induced psychosis around Covid times. Now I suspect all the plastic people are consuming.
People don't get any engagement and media sensationalism for finding no evidence. Now that society is biased towards that instead of truth, "maybe" is the best they can do.
Is it microplastics or nanoplastics or both?
How many types of plastic are there, half a dozen? What type of plastic do you want to test, what about multiple plastics in different proportions?
It can be difficult to identify mechanisms behind adverse reactions to more obvious stressors, let alone something like this which appears more chronic, long-term, and insidious.
1. https://grants.nih.gov/grants/guide/notice-files/NOT-ES-23-0...
Several dozen major ones, starting at cellulose.
And before you think I'm missing the point: Well, no, cellulose didn't biodegrade for what IIRC several hundred million years. That's why there's no such coal.
It still barely biodegrades.
Even if it requires 'macroplastics' concentrations to cause problems, inert still doesn't mean harmless. One example which comes to mind is that senescent cells are 'inert' compared to cancer cells and they appear to be responsible for /have a role in aging's damage to tissues.
We ARE, it's just that nobody cares (or can figure out why)
50% of men will get cancer. Autoimmune diseases become more prolific over time. Fertility has been spiraling for decades. Mental health issues are on the rise.
Even at low concentrations (1–30 µg/ml), photoaged microspheres at 1 and 5 µm in diameter exerted more pronounced biological responses in the A549 cells than was caused by pristine microspheres. High-content imaging analysis revealed S and G2 cell cycle accumulation and morphological changes, which were also more pronounced in A549 cells treated with photoaged microspheres, and further influenced by the size, dose, and time of exposures. Polystyrene microspheres reduced monolayer barrier integrity and slowed regrowth in a wound healing assay in a manner dependent on dose, photoaging, and size of the microsphere. UV-photoaging generally enhanced the toxicity of polystyrene microspheres in A549 cells
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10176241/
Maternal exposure to microplastics and nanoplastics has been shown to result in fetal growth restriction in mice. [...] Maternal exposure to both microplastics and nanoplastics resulted in evidence of placental dysfunction that was highly dependent on the particle size. The umbilical artery blood flow increased by 48% in the microplastic-exposed group and decreased by 25% in the nanoplastic-exposed group compared to controls (p < 0.05). The microplastic- and nanoplastic-exposed fetuses showed a significant decrease in the middle cerebral artery pulsatility index of 10% and 13%, respectively, compared to controls (p < 0.05), indicating vasodilation of the cerebral circulation, a fetal adaptation that is part of the brain sparing response to preserve oxygen delivery. Hemodynamic markers of placental dysfunction and fetal hypoxia were more pronounced in the group exposed to polystyrene nanoplastics, suggesting nanoplastic exposure during human pregnancy has the potential to disrupt fetal brain development, which in turn may cause suboptimal neurodevelopmental outcomes.
https://pubmed.ncbi.nlm.nih.gov/37724921/
PS-MPs can decrease transepithelial electrical resistance by depleting zonula occludens proteins. Indeed, decreased α1-antitrypsin levels in BEAS-2B cells suggest that exposure to PS-MPs increases the risk for chronic obstructive pulmonary disease, and high concentrations of PS-MPs can induce these adverse responses. While low PS-MP levels can only disrupt the protective pulmonary barrier, they may also increase the risk for lung disease. Collectively, our findings indicate that PS-MP inhalation may influence human respiratory health.
https://pubmed.ncbi.nlm.nih.gov/31727530/
(TL;DR; they are affecting our bodies for the worse, even as feti)
Aren't plastics by design long chains of molecules? 1 nm is like a handful of atoms at most afaik. How small do plastics get?
A 10-carbon chain with its hydrogens attached can hardly be called "polyethylene"; it is a higher alkane and behaves more like wax or mineral oil than what most people would call a plastic:
https://en.wikipedia.org/wiki/Higher_alkanes
I wonder if the PE they are finding is actually https://en.wikipedia.org/wiki/Petroleum_jelly
"you think your job is bad, kaitlyn? get a load of what dr. campen's got me doing this week!"
https://www.thomassci.com/Equipment/Homogenizers/_/Polytron-...
Remember when RF was the boogeyman? Paranoia about microwave ovens and cellphones causing cancer and other illnesses?
Even the Antarctica is starting to see microplastics: https://www.smithsonianmag.com/smart-news/in-a-first-micropl...
Monkeys with hand Grenades. Humans with plastics.
I wonder if this correlates with the rise in the use of 'compostable' (i.e. weaker) plastics, that are more likely to break down during use.
27 organ material samples from 2016 and 24 samples from 2024 - but they don't say if they're from different people. I assume they are but it's not stated.
Just wondering how much the increased age would have contributed to differences between the two years.
It was different people who died in different years.
We have no evolved defence against compounds and materials developed in the last century.
This different paper talks about this approach and its limitations: https://www.mdpi.com/2673-8929/1/2/16
"Prior to Pyr-GC/MS analysis, environmental samples undergo purification steps to isolate MP from the environmental matrix. However, this purification is not complete, and several organic and mineral constituents survive these treatment steps, especially in complex matrices such as sediments or soils. Hurley et al. [15] reported that the efficiency of removing organic matter from soil varied from 34% to 108% depending on the used reagent (H2O2, Fenton’s reagent, NaOH, KOH). These remaining particles will hamper the characterization and quantification of MP particles through Pyr-GC/MS. Upon thermal cracking, the polymers release pyrolysis products of lower molecular weight. Some of these products are defined as indicator compounds when they allow the detection of targeted polymers. However, some constituents of the remaining natural organic matter may release the same pyrolysis products as the targeted polymers [15,16,17,18], hence a potential MP overestimation. The identification of pyrolysis products that are specific to the targeted polymers is therefore necessary."
Sounds like the detection methods and methodology for microplastics are evolving. It is plausible that the amounts are materially over estimated.
Another thing that seems implausible is the increase between 2016 and 2024? "our finding that total plastics mass concentration in brains increased over 50% in the past 8 years.". 50% in 8 years! Is the world really that different in terms of plastic exposure 2024 vs. 2016. Unless something has fundamentally changed with the food supply in this period how can this be possible? Plastic production is increasing (https://www.statista.com/statistics/282732/global-production...) but for a 50% increase in this period something would have to have fundamentally changed with exposure routes in this period.
The extent to which microplastics cause harm or toxicity is unclear, although recent studies associated MNP presence in carotid atheromas with increased inflammation and risk of future adverse cardiovascular events2,3. In controlled exposure studies, MNPs clearly enhance or drive toxic outcomes4–6. The mantra of the field of toxicology – “dose makes the poison” (Paracelsus) – renders such discoveries as easily anticipated; what is not clearly understood is the internal dose in humans.
An association means little considering Microplastics are more commonly found in garbage ultraprocessed food.
And the second part of your quote is saying we can make anything toxic in a controlled exposure if we dose it high enough
You can’t do a double-blind randomized control trial.
And we have barely learned to measure these nanoplastics.
But there are starting to be strong correlations between the plastic occurrence and terrible diseases. Recent data on atherosclerosis + infarcts is horrible.
Recent data on testes production of sperm cells also looks very damning.
In summary, there are a few unexplained things in medicine that might very well be caused by plastics. Eg. More colon cancer in young people in the west. Eg. Declining sperm quality in the last 30 years in the west. Yes, it could be foods, but it doesn’t explain the whole picture. Plastics could be it.
My guess is that a LOT of nasty studies will come out in the next years.
I switched to glass and metal for all my food and water, for as much as I can control it.
You could on animals.
There are situations where overthinking it is bad. Yes, obviously, microplastics in your brain are bad for you. Common sense. Any delay because "the science isn't there yet" does more harm than good.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9885170/
> Endocrine toxicity induced by MPs is an emerging issue, despite the subject being rarely documented, there is growing evidence for ingested MPs bioaccumulation in mammalian tissues and organs with deleterious outcomes including endocrine abnormalities, reproductive toxicity, gut microbiota dysbiosis, and defective immunological responses in rodents, rats and mice.
And:
> However, there are still no conclusive research reports that have determined the direct consequences of MPs and NPs on the hypothalamus, pituitary, and adrenal gland.
However, “absence of evidence is not evidence of absence.” These microplastics are definitely on the more suspicious side, just like tobacco use was.
Unfortunately we do not live in that universe.
Sometimes I read accounts on industrial revolution England and think “how the heck people survive THAT.” Several decades from now there will be people who think of us the same way haha.
https://www.prnewswire.com/news-releases/national-safety-cou...