Micro- and nanoplastics breach the blood–brain barrier in mice
mdpi.com
mdpi.com
The limited science we do have unsurprisingly indicates that it is.
It’s weird to me that a lot of HNers, like I see with western doctors, believe that until something is conclusively proven in peer reviewed research it should be treated as if it doesn’t exist at all. IMHO that’s irrational and robotic, there are such things as safe assumptions and educated guesses.
Plastic is pretty chemically inert. We've been using it widely for decades to great benefit and there is no strong evidence that it's harmful. I would not be surprised to find that in the body it's basically benign.
Or maybe not, but I don't see how you can "know" either way, without scientific research.
https://www.thelancet.com/journals/lanpub/article/PIIS2468-2...
> These findings seemingly contradict a previous GBD estimate published in The Lancet, which emphasised that any alcohol use, regardless of amount, leads to health loss across populations.
https://www.thelancet.com/journals/lancet/article/PIIS0140-6...
I don’t understand how one could read user3939382’s comment and conclude that the expressed position is that we don’t need science.
That’s not at all what they said. Rather, they were advocating for the application of the Precautionary Principle while waiting for science.
You're very much fighting the "healthy lead" fight
Fertility rates are dropping for different reasons--fewer individuals choosing to enter into long-term relationships and have kids, and families choosing to have fewer children on average than previous generations.
[1] https://www.hopkinsmedicine.org/news/newsroom/news-releases/...
1. You can't prove a negative.
2. What constitutes a change from the status quo? The status quo is a vague concept in a dynamic world.
So you have to use some judgement. Plastic is really, really safe in small amounts. Same with CO2 emissions. It's only in huge quantities that they are a problem.
This is the critical thing. People are really really bad at nuances like “harmless in small quantities, harmful in large”. People tend to want to argue whether X is good or bad in a totally contextless abstract, like sports fans taking fandom too far.
HN doesn’t seem better than reddit or fox news in this respect. It seems to be fundamental to human nature. And yes, I know I do it as well. Such a frustrating bug in human cognition.
Or maybe we discover some sort of light/sound/other wave/something that, like an x-ray, has low enough health risks to be worth sometimes putting through humans, but that somehow does something to plastic that will let the body dispose of it all?
Or maybe some drug gets created that somehow turns on some bodily function that can handle the plastic problem.
Or.... I don't know, I'm no expert, but I bet there's more possibilities.
Of course, would be good to do our best to reduce plastic use altogether anyway, for environmental as well as health reasons!
[1] https://interestingengineering.com/science/bacteria-really-c...
Don’t take new plastic, and in a few years you should be good.
Nanoplastic circulates in the bloodstream which is continuously refreshed, or sits somewhere in the cells which are continuously disposed of.
Some toxins or heavy metals can accumulate in bones, but I’m not sure if plastic can do that.
macrophages breaking their bonds? (I'm not sure...that's a question)
https://jamanetwork.com/journals/jamanetworkopen/fullarticle...
You can dual filter, smaller and larger than, but you'd still have plastics.
Thanks
Why isn't blood letting mentioned more?
Probably not.
> 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.
Still concerning, of course. They didn’t really do any quantification of how much this happened, they just administered rather extreme concentrations of deliberately produced nanoplastic formulas and then later found a couple particles in brain sample images.
The images they included (scroll down to Figure 3) are somewhat confusing in that they all have green dots in them, but only some of the dots are labeled nanoplastics. Even the control mouse has a lot of little green dots, but they’re not identified as nanoplastics for reasons I don’t understand. Someone more familiar with the subject matter would have to comment on how reliable this method is. The number of green dots is strikingly large in even the control mouse, so clearly they’re not all nanoplastics.
> These findings together with the computer model underline that MNP PS particles can cross the gastrointestinal barrier and the BBB within a short time, but only 0.293 µm sized particles were able to be taken up from the gastrointestinal tract and to penetrate the BBB. This suggests that the size of the particles may be a critical factor in their ability to penetrate the BBB [42].
> 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.
I'm not downplaying the problem at all. If microplastics are in major organs that is a serious problem that warrants additional research or even outright bans. However, if microplastics are getting to the brain I think there'd be conclusive evidence by now.
But these corporations put out metric tons of it externalizing the cost to everything and everyone. While the individual is told they can’t have a plastic bag or straw, and that we can recycle our way out of it (which is a scam — it was shipped to China, not recycled). Thanks corporatism! Government is carrying water for corporations while individuals are distracted into thinking they can clean up the mess with personal action [3]
1. https://extension.psu.edu/microplastics-in-our-waters-an-unq...
2. https://www.theguardian.com/environment/2022/mar/24/micropla...
Now, metal recycling is definitely a thing. Recycling alu or iron is definitely a valid thing. It costs a lot of energy to convert iron ore or bauxite into the associated pure metals.
Countrywide laws that could change how recycling and products work: require cradle-to-grave product laws, and then make the source responsible for disposal. (That would turn the current externality into an internality. And their scale would help solve it.)
https://www.nytimes.com/2019/04/15/business/yellow-vests-mov...
Furthermore, if you redistribute a UBI to the people, it makes the tax popular. This is massively important in a society that's tax-averse, and helps gather support for actually solving collective action problems.
Your third citation is a weird ranty blog about everything from anarcho-capitalism anti-vaccine rants that is more angry than informative, but it’s somewhat beside the point: We are making laws to reduce microplastics deliberately introduced to products. Asking the entire world to stop using plastics immediately isn’t a real option. Individual action does have a significant effect, as the highest numbers of microplastic/nanoplastic particles are found directly inside of plastic containers like plastic water bottles. Several orders of magnitude higher than your government-provided tap water.
Your characterization of having the entire world stop using plastics “immediately” is a strawman. We had decades. The amount of plastic has only grown, while R&D into non-biodegradable alternatives doesn’t get mych funding by comparison. The suggested solution is to have governments fund a UBI with Pigovian taxes. We can’t even pass this: https://csas.earth.columbia.edu/sites/default/files/content/...
We the People should be angry, since we and our children will have to live with the consequences of this dysfunction and inaction, and increase in production and consumption of these things which externalize the cost, thanks to the profit motive. The list of things in that third link goes way beyond plastics. This is how our system works. Ours is an environmentallh irresponsible generstion living on an ecological credit card. The individuals are distracted from banding together to vote in governments that will pass a Pigovian Tax and Dividend on an increasing number of negative externalities. It requires a political movement, and anger is a great motivator and uniting force.
In that third link, I list all the narratives individuals are told, in order to take focus away for governments and corporations, and onto shaming individuals into performing individual action downstream of the actual problem.
You think we can just stop using plastics in a couple decades?
Look at what we did with CFCs globally when we came together — that is a massive success:
https://en.m.wikipedia.org/wiki/Montreal_Protocol
We can also help reduce meat consumption gradually with more products like Beyond Meat and Impossible Foods etc. but it is far better and more effective if the government gets involved and taxes factory farms.
As a side note, I know the alternatives have to be good enough before people switch, because I have been building https://qbix.com for OVER a decade, and only now we are ready to present an alternative to the Big Tech monopolies no one can exit because they lack viable alternatives. This problem is everywhere in capitalism.
If I limit my personal use of products like these, will this keep microplastics from entering my body? Or is there an effect from the broader environment, regardless of my personal initiatives?
Also, will there be enough products that eliminate microplastics that it won’t be a huge cost/effort burden to go without?
It’s not possible to keep micro plastics out of your body 100%, but like everything it’s a question of how much. Even your tap water contains compounds like cyanide in trace amounts that we can measure, but that just says more about our ability to measure Tony quantities of compounds. You have to look at the relative significance of different amounts.
This works for other forever chemicals, it may work for micro plastics:
> Regular Blood Donations Can Reduce Toxic Forever Chemicals in the Bloodstream: Study
> https://theswaddle.com/regular-blood-donations-can-reduce-to...
In Seattle I've tried to donate blood multiple times over the last decade.
Every time, "because I've been to India in the last 5 years" they are unable to take my blood. Something about the risk of malaria. At worst, given a shortage, why not take my blood and analyze it? maybe even clean it (like with a dialysis machine)?
Talk about a dumb rule. Anyways... is there some other way to get this advantage? Are there blood letting doctors?
Also afaik it is 3 months[1] for malarial region (like India) it was updated from one year after FDA guidance changed in 2020
[1] For former residents of malarial region you must have resided outside for three years first, here is link to the full guidance from FDA
https://www.fda.gov/regulatory-information/search-fda-guidan...
https://www.horiba.com/int/scientific/resources/science-in-a...
the main source of microplastics is synthetic textiles. There is a serious argument to be made to ban synthetic textiles in areas where they can be reasonably replaced with cotton.
The other main sources are "city dust" and car tires. I suspect those types of microplastics are much harder to reduce.
Second, I agree with the conclusion that more research is needed. I’d love to know what effect these plastics have on brain function.
Is there a way to clear them at all? Even with medical assistance? There is chelation therapy that can clear some heavy metals. Anything like that for nanoplastic?
I have no idea so I submit the question to the hive mind.
>Brain damage and behavioural disorders in fish induced by plastic nanoparticles delivered through the food chain
It’s MDPI. The no-paywall thing is part of their predatory scheme. Along with blazing fast reviews with not too many questions asked. Seriously, it’s completely unbelievable that any significant article would be thoroughly reviewed in 2 weeks, as this article seems to have been.
> Second, I agree with the conclusion that more research is needed.
Indeed.
Glass and many other materials that can be nano-ized can do the same.
Polysorbate 80 can open the BBB even more. Just take a vaccine.
Isn’t that just clay?
Can't we just do some scans/biopsies on humans to assess if we have plastic in the brain and start from there?
How does this experiment further anything? I'm kind of appalled that this is some people's job - it's pointless, stupid and cruel, and done by scientists who get paid the big bucks doing it.
I know I'm a little ranty - but I'm serious. Why do people do these experiments?
I'm sorry if "the big bucks" sounded like over 100 000$ for every single one of them.
Some guy still got a grant to feed mice plastic, didn't he?
Not to say there isn't good science being done, but I do question the ethics.
I'm not a scientist, but couldn't we check cadavers for microplastics? Wouldn't that be more concluent?
You're right about the cadavers! Maybe such a study exists and we could skip ahead to agreeing its a problem or perhaps we enter the next phase: "are we sure these plastics in my brain are akshuuuaallly a problem, perhaps they are making me less stupid and more healthy MR SCIENTISTS"
One does not prevent the other.
Anyhoot!
Definitely! That is completely legitimate and suffering must be avoided as much as possible.
But sometimes such experiments are necessary and cannot be easily avoided. The alternatives are not understanding what is happening (which is ok if the thing is harmless; I don’t think that this is the default hypothesis for nano-plastics), or doing the analytical experiments in humans.
> I'm having problems seeing what usable data was extracted from these mice that wouldn't have been found some other way
Off the top of my head, in this setting we control exactly the amount of particles and their size, which is important to assess the mechanisms by which they penetrate the tissues.
Looking at dead humans has a huge sampling bias (people giving their body are not representative of the population as a whole), and we have no idea about the kind of particles they were exposed to, or of any other factor that could affect what we want to quantify. Maybe some kinds of substances can increase or decrease penetration rates (things that affect blood pressure, for example). In a controlled setting, we know that all mice were exposed to exactly the same conditions.
The study in question found microplastic in 80% of test subjects. The presence of these particles is likely not new, just that it's been difficult to detect them until now. Buckle up, we're not likely to find out that they give us superhuman abilities.
That's not been argued, we're arguing the salaries of the scientists instead - not certain why.
I haven't talked abount embezzeling anything or that experiments are useless - just that I can't see why this one was done, and it makes me weary of most experiments on animals, even more than I normaly am, as they seem much more arbitrary than I would have liked to think.
Thanks for your insight and snarkiness anyway.
Lab animals are kept in regulated conditions (illegal/unethical behavior under the radar aside), experiments are vetted by institutional review boards, and they live pretty decent lives. There is mandatory sensory stimulation, handling, and socialization.
If you want to get rid of animal models, kiss basically every medical intervention goodbye (drugs, prosthetics, procedures, surgery).
As for having my brain biopsied - I'm not the one arguing that we have microplastics in the brain. The scientists had this hypothesis, and killed some mice to prove it. I'm saying that they shouldn'y have been allowed to, since the result does not further anything about plastics in human brains, and other options seemed both to provide better human data and be more ethical.
Anecdotal example: I have met a british guy who makes a living from participating in medical trials. He makes about 10-20k per year if I remember correctly.
As for your example, I too knew someone living a pretty terrible life doing trials for a living, that died sadly. While I understand your point, I'm sure you can think of many avenues for this person to make a living without doing trials - i.e. stocking shelves, working a warehouse, janitorial work, service, etc. If they are under precarious circumstences, there are many options still.
Uh, no. Grad students make bupkiss while they could easily pull six figures after completing a bachelor's. They do this because they are a curious, masochistic bunch who find working on important problems to be a worthwhile endeavor.
And is feeding mice plastic and then seeing if they have plastic in them a worty endeavour? It's fine because they aren't paid as well as if they were working corporate?
I'm also aware that a lot of people have to tailor their doctorate work to their advisor, meaning it could very well be that no one doing this experiment was "curious" or believing that it was "important".
I'm sure you know many bitter PhD's that studied things they find utterly pointless today - I had many teachers laughing at their own peer reviewed work.
Here's data for CMU:
https://www.cmu.edu/stugov/gsa/campus-advocacy/stipend-repor...
While it's not rich people's money, it's more than enough to be very comfortable, especially compared to someone working minimum wage.
I don't feel bad being very critical of how their time is being spent - especially here.