The longer it goes without concrete and clinically significant findings, the larger I think the probability of the findings being wrong becomes. I also find it strange that so few of the studies I have read ever comment on the fact that our system might be fully capable of removing the nanoparticles by itself, just as it removes everything from dust to methylmercury. We do not know if this is the case, but the fact that nobody is addressing this further strengthens my fear that there is a lot of confirmation bias going on.

Every time I post something like this, I get a lot of angry responses, so I can try to preempt some of them by saying: I am not asserting that microplastics are safe. But the pattern of lots of pilot studies, and few studies that significantly prove the theory, is very recognizable to me.

Until someone either conducts a naturalistic experiment with lots of people exposed to large doses of microplastics and compares them to a control group, or we expose some larger animals to microplastics over a long time in a true randomized controlled study, I'm going to remain skeptical.

But there's also a practical weight that matters in a lot of these pursuits. Plastics overtook the world during a time when people weren't really considering their impact at ecological scale and didn't have sufficient models and tools to really assess what they might do to biological systems over lifetimes or generations. It was a historical accident that happened fast and without many brakes applied and now "plastics everywhere" is a pervasive background noise that's very hard to meaningfully control against. So the controlled science which was never conducted initially, and we now think probably should have been, is almost impossible to perform because we're left in that that fuzzy "soft sciences" place where everything is already plasticked.

But does that mean we should just keep charging ahead without trying to look, and that maybe a mindful step back from unscientific historical use would be worth considering even without conclusive evidence (since such evidence is now too hard to gather)?

We've been using plastics for a long time. They improved the world in important ways. There's nothing we can detect in large-scale studies of industry workers or other exposed groups that would suggest they're dangerous. That's kind of it. Every story you see on HN about microplastics is hand-wavy and involves dubious assertions and hypotheticals, and the alternative is... what? That we go back to making all commodity items out of metal, with a more serious environmental impact, higher transportation costs, and so on?

There are wasteful uses of plastic which should be curtailed, e.g. for packaging fresh produce - but the concern here isn't microplastics, just pointless trash.

We know enough about heart attacks to know they can be caused by plaque build-up in arteries. We don’t know enough about nano-plastic or micro-plastic buildup in our bodies, or its effects.

At the very least, it’s worth investigating the role of plastics and ruling it out.

Many technologies have been studied properly and been found to be safe or unsafe. Smoking, non-ionizing radiation, airbags, alcohol consumption, exercise, beta-blockers, metformin, GLP-1, antipsychotics—all of these have been well studied and have been found to be clinically, not just statistically, relevant with regards to safety. Even vaccines are much better studied and understood with regard to risk compared to microplastics. So, I don't think I am just randomly picking on plastic research. I am holding it up as an example of research areas that are triggering skeptical red flags, as opposed to research that isn't stuck in the speculative phase.

I also wasn't commenting on the issue of overproduction of goods, which I have thought about, but that is not what I was focusing on here.

Otherwise it feels a bit like an argument from anxious cynicism: "There must be a major danger or tragedy with everything including X, if we don't see it, that just means it's been good at hiding."

Plastic nanoparticles isn’t a single thing. There are many types of plastics, with many types of additives. Most plastics are bioreactive, especially when not handled properly or maintained in the proper conditions. A great many plastics and especially additives are known to be toxic, carcinogenic, etc. These aren’t controversial statements and is widely known, understood, and cataloged.

Further, in this study, they point to prior studies that have established most adult humans have detectable amounts of nanoplastics in the blood stream. Further the point to prior research establishing many nanoplastics (and specially polystyrene, what they are studying here), passes the blood brain barrier.

They contribute findings that, in mice, polystyrene nanoparticles are admitted to neurons and they isolate a number of changes in the proteins and signaling of the cells that propagate to other parts of the brain. The changes are indicative of changes observed in Parkinson’s, but since we don’t understand Parkinson’s, we clearly can’t establish a causal link in this way.

RCTs could establish a probable correlate, but given again plastic nanoparticles are a single monolithic thing, there’s an incredible amount of variability in such a trial. This will take a lot of time and need to be pretty narrowly constructed so fundamental research like this is how you establish and guide such trials in the future. We haven’t really focused on the subject very long. But all of the facts above should be of grave concern.

Even if the body clears out nanoparticles, which I’m certain it must, that doesn’t mean they can’t cause serious issues prior to clearance. We are also presumably constantly exposed to more so you should view it as a chronic and persistent level in the body even if the body can clear it. In fact I would say unlike heavy metals we almost certainly clear it otherwise you would simply accumulate greater and greater concentrations; which I don’t think is observed.

It’s good to be skeptical, but I don’t think “we haven’t established a specific disease caused by the pervasive presence of plastic nanoparticles in animals” doesn’t imply “this is ok” by any measure.

With regard to your last point, I kind of agree, but there has to be a balance between two extremes. You can't assume something is safe just because you don't have a smoking gun. On the other hand, the "you can't prove it's 100% safe for everybody at all times throughout the universe, so we must assume it's dangerous" position can also be very dangerous. To me, the anti-GMO movement makes this mistake in a serio

us way, hurting actual people in deprived parts of the world. I fear that the microplastic scare is overblown and takes focus away from much more important issues.

> "Researchers said the plastic[polystyrene]-protein accumulations happened across three different models performed in the study - in test tubes, cultured neurons, and mouse models of Parkinson’s disease. West said questions remain about how such interactions might be happening within humans and whether the type of plastic might play a role."

Another thing to keep in mind is that Parkinson's appears to have a whole lot of different causes or risk factors, which accumulate as we age, from genetics to exposure to organophosphorous pesticides and this is just one more added to the list (wiki):

> "PD is believed to begin principally by degeneration of dopaminergic nigrostriatal neurons in the brain and secondarily by complex pathological mechanisms, including mitochondrial dysfunction, oxidative stress, apoptotic cell death, protein aggregation and misfolding, inflammation, excitotoxicity, loss of trophic factors, and other cell-death pathways"

So, it's not about 'plastics' in general, it's just that there are specific types and additives that should probably be phased out.

Good luck finding a single person on earth (let alone, a group) not exposed to microplastics.

The “forever chemicals” were found in even the most remote areas of the world. Wind, rain, storms, and other natural events carry this junk and spread it all over the world.

There is literally a massive plastic graveyard in the ocean. Plastics turning into micro/nano plastics. Infiltrating food (fish), water, and carried into populations.

By your reasoning we can just call anything chemicals, as all physical matter are a mixture of chemical elements.

Words matter. Sand is not a chemical.

I'm sure there are more scientific ways to do a study.

That means double blind experiments. Your correlative studies don't offer enough evidence. Causation is our strongest scientific metric.

Human causative experiments are worth it as well in my mind with paid volunteers who are aware of the risk. But the legal barriers here are likely high.

We can start with chimpanzees.

What you are describing here is "pursue as dogma"

Plastic is made from refined natural gas and crude oil. We know for a fact those things are carcinogenic. There is no universe where putting them inside your body is not bad, and we should be doing everything we can to reduce it.

> a naturalistic experiment with lots of people exposed to large doses of microplastics

Are you volunteering to be in that group? Why not?

This is the type of ignorant generalisation that causes the widespread paranoia we're discussing here. Crude oil consists of a mixture of literally hundreds or more different compounds. Benzene is carcinogenic, and so are a few other aromatics. Methane isn't, and neither are the other pure alkanes. The keyword is "refined". Highly refined mineral oil isn't carcinogenic. Neither is petroleum jelly.

Of course you don’t

The usual response I get is something like, "that kind of research is really hard to do." My response to that is, "conducting just easy research is not only unhelpful but actually detrimental to the field."

What is the experiment you are proposing here exactly? It sounds like you want to give extra microplastics to a randomly selected group for tens of years, and then comparing the incidence of Parkinson disease among them compared with a control group who was administered some placebo. Is that what you are proposing?

If that is what you are asking for then that is a “never gona happen unless you go full Mengele, and even then it is hard” type of research.

Alternatively, compare the sickness rates in a population near a new factory emitting microplastics with a similar population elsewhere. With many potential sites, extensive on-site research could yield valuable insights beyond what is available from desk-based studies.

Or, consider an experiment where you add plastic to one fish-filled pool and use another pool as a control, monitoring the ecosystems over a year or two. This could provide more robust data than some commonly seen studies.

It's impossible to know that the vaccines are net life-saving without proper placebo-controlled RCTs. Without that, you just have scientific-sounding marketing material.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10602106/

The in vivo study involves injecting nanoplastics directly into the brain of mice along with human α-synuclein fibrils, so is one step up from in vitro work but still quite artificial.

In sum, it does not demonstrate that nanoplastics in the environment, or even those that might be directly administered to mice, e.g. in food, have any effect on Parkinson's-like symptoms or pathology.

Edit: I should add that laboratory mice are often in contact with plastics that they chew on. So it's highly unlikely that ingesting plastics has any effect on mouse models of Parkinson's as this would have been noted decades ago.

Doesn't it only mean there were no control group? Just like when they found out that mice suddenly started dying less when they raised lab temp a bit.

However, mice that have human α-synuclein have been around for decades, and nobody has (so far) noticed any effect of plastics on the development of Parkinsonism in these mice, neither are there any claims that Parkinsonism is more prevalent in people who have plastic implants of one kind or another.

Note that people ingest plastics all the time, e.g. through the breakdown of toothbrush bristles.

Plastics are found in human blood/lungs/breast milk/placenta etc, so the concern is much stronger than just accidental ingestion from a toothbrush.

Read about effects of xenoestrogens, which a bunch of these plastics apparentlt are, and cross check with some realities of today.

Yes, I appreciate the risk of plasticisers, and these should be addressed.

However, by the time an item made of plastic has become a "microplastic", these plasticisers have been leached out.

Haven't we learned by now that if journalists are using scary headlines it is because they have nothing better to report, and if studies are concluded with 'we need to look into this more because data is scary' it means they didn't have anything better to conclude?

Let's all calm down and wait for the other shoe to drop, if it does, and in the meantime communicate the message: 'these scares happen every decade, it is nothing new and we are still around, let's wait for some evidence before we panic'.

And take this opportunity to say 'enough' to single use plastics when there are better options. It is absurd that we let it get this far. Let's go back to glass for liquids at least, and get rid of the 'wrap everything in a layer of plastic' tendencies that are completely unnecessary.

You don't need a double blind study to look at smoking and say "inhaling smoke is probably bad for you". Likewise you can look at the evidence of microplastics being bad for human health and say "ingesting random synthetic chemicals that bio-accumulate and are hard to break down are probably bad for you".

Obviously panic isn't helpful. But I've switched anything that has to touch hot food/liquid to some combination of glass/metal. I've also started buying milk in glass containers. All of this has had zero impact on my life beyond some upfront cost buying glass food storage containers and making milk more expensive. I'd recommend everyone else who can afford it do the same.

Even in the 1950s when everyone smoked everywhere and you couldn't escape second hand smoke outside of the house, it was still a healthier choice to not smoke yourself.

Side: Unfortunately in multi-family apartment buildings in tropical places like India where balconies are common, even escaping second hand smoke in your own home is difficult if you don’t keep your windows always closed to the neighbor below you.

Good observation, as a general rule any new substance must generally proven to be safe ( and there are reasonable ways to do it, without being overly cautious), it must not be a case of proving that something is harmful once in use.

It's like continuously pouring small grains of random dirt you scraped off the ground into your car's engine while it's running, when you're not entirely sure how the engine works, and going "meh, they're just tiny particles of dirt. My engine is still running. Probably fine". You can run that experiment on your one and only body if you wish.

If only fruits and vegetables had robust, natural, bio-degradable packaging of their own. Some sort of peelable skin, perhaps.

That is the thing: they rot. And if wrapped in plastic, they last longer ... so more fruit makes it to the markets. That being said, I strongly prefer fruits directly from trees that were not treated with 50+ different chemicals.

Food forests were very much a thing, for a very, very long time. Thousands of years.

And whether food forests were a big thing and not just common in some areas, is quite disputable.

Do you want to compare the actual plant - size, nutrition profile?

Do you want to compare the growing methods - monoculture pesticide gmo corn vs heirloom corn?

Food forests being a big thing is disputed by some people, that doesn't mean they didn't exist, and it certainly doesn't mean that we couldn't do the same thing but better if we made an effort to.

It irks me when people use 'the way we do things now' to dismiss alternatives with great potential. What's the motivation there?

Where's the logic in saying 'we can't do that, because that's not how we are doing things now?' It's stupid, and it shows a complete lack of imagination.

Food forests being a BIG thing all around the world is something many people, myself dispute. So you make a claim against the common consensus, it is up to you to proof your point.

"Where's the logic in saying 'we can't do that, because that's not how we are doing things now?'"

And the logic is, now there are way more people to feed. And I have actually seen quite some alternative permaculture communities. Usually they struggle to feed themself, let alone feed others(usually cannot live off their huge land at all). You cannot live off imagination. You need solid food.

And food forests do have some potential, but not to feed the world.

Maybe that's true. But, does it actually matter - at all - that some communities didn't work? It shouldn't, but you think it does. That's weird.

> food forests do have some potential, but not to feed the world.

Think those goalpoasts just broke the sound barrier. We went from "food forests would let people eat fruit with less pesticides" to "well they won't feed the entire planet".

And you're still wrong. Food forests will have a critical role in feeding the world sustainably. It's not just about calories - it's about soil health, diversity, fairness, carbon sequestration.

> You cannot live off imagination. You need solid food.

There's no call for this kind of condescending strawman. It's very much against the guidelines here.

Can you point me then towards some communities, that do live off their land? Without pesticides?

Like I said, I have seen quite a few. But usually those with the biggest words had the lowest yield. And no doubt some can do it. (Conventional organic farming obviously does work). But the combination of permaculture and food forest and alike I have not seen work. Nice looking gardens, yes, but simply not enough solid food as an outcome.

And in general:

"There's no call for this kind of condescending strawman. It's very much against the guidelines here. "

Well, then maybe reconsider your words before?

"It's stupid, and it shows a complete lack of imagination."

Modern synthetic pesticides were invented in the 40's. Natural pesticides have been used for thousands of years. Your question doesn't seem to discern a difference.

> Well, then maybe reconsider your words before? "It's stupid, and it shows a complete lack of imagination."

That wasn't a strawman, nor was it personal. And it's 100% true, so I'll say it again - using the way things are done now to shut down ideas for making things better is profoundly stupid and unimaginative. If you think that mean I'm saying you are stupid, well...

The difference is still the number of people between then and now. So far it is a hypothesis, that we can feed everyone without conventional agriculture methods.

There is no evidence despite all the research evidence?

Or do you mean, there is more evidence that cell phones do not cause harm, than there is that they do cause harm?

I don’t know why the burden of proof is so difficult for people to understand. If you make a claim, the onus is on you to prove it, not for others to disprove it.

I am confused. Why are you talking about cell phones?

Heavier, easily breakable, and far more expensive to process?

It would be interesting to see what relationship exists with allergies here as well, which are also becoming more prevalent for reasons we don't yet understand.