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I had strong echoes of a naieve lab experience in the 1970s: testing for organophosphates in seawater at the Forth Estuary was basically impossible except for gross amounts, because the standard analytical glass washing we used contaminated the glassware. You have to maintain a completely independent suite of glassware from pipettes all the way through to reaction vessels, and chromatography cells, and wash them with chromic acid, or special formulations.
(I don't work in this field any more, I was a lowly bottle washer and lab tech on a job creation scheme, I am sure the field has moved forward)
Similar issues plagued tests of iron concentration in seawater. Sample collection was contaminating the samples for years, until a procedure to collect a non-contaminated sample was developed by John Martin. He was able to finally figure out that actually most ocean water was iron deficient (that is to say: iron was the limiting factor in phytoplankton growth). Testing for environmental contaminants, especially in things that are commonly used by human civilization is really tricky.
People seem to be misunderstanding this paper. It doesn't claim that any previous papers have overestimated contamination. That would only happen if scientists didn't routinely use blanks as a comparison, which they do.
E.g. "A procedural filter blank was created during each sample batch and analysed alongside the samples, to enumerate potential contamination that could have been introduced during the extraction process."
https://eprints.soton.ac.uk/476076/1/1_s2.0_S014765132300286...
This is an overstatement of the protection that blanks provide. As it says, they only (potentially) provide insight into contamination caused during the extraction process.
This is why it is good lab procedure to always "run a blank." A blank is simply a sample that is constructed exactly like a real sample but without the thing you are studying. This way you quickly learn about contamination from tools/gloves/environment etc.
If microplastics are everywhere in flesh/brains/etc., how do you construct a blank without them? Isn't that the very issue here?
Here's a very naïve example to help illustrate how you can do a "blank" (a control).
Say you're testing a sample of water in a test tube. Repeat all steps in exactly the same way, but use distilled water. You can even do all the steps and use no water! (Including having an empty container and pouring nothing from the empty container into the test tube).
By doing things like this you create samples that allow you to look for contamination. How do you know that the thing you're testing has microplastics? (Or whatever) because it has more than the blanks/controls. That's it. Congrats, you've isolated a variable in your experiment.
Btw, this is pretty common practice. In fact! Here's a video of someone doing exactly that "nothing" control looking for microplastics. Those steps are done at 10:20.
> Repeat all steps in exactly the same way, but use distilled water. You can even do all the steps and use no water!
This is where I get lost. Maybe I don't understand what a blank is.
If you have access to distilled water that you have excellent reason to believe is free from what you're detecting, then great. But my point is we don't have access to animal flesh guaranteed to be free of microplastics, do we? Because they're everywhere in the environment.
And if you use no water at all, it seems like you're missing the entire vector of contamination from acquiring and transporting the water. E.g. if the water container is producing contamination, then your blank of no water isn't revealing the source of contamination! The blank isn't helping at all.
I don't have any issue with the concept of a blank sample when they're feasible. My issue is, I don't see how you can produce a blank sample of animal tissue without microplastics specifically because microplastics are everywhere in nature, and I don't see how a slide with zero animal tissue at all is a useful blank.
> If you have access to distilled water that you have excellent reason to believe is free from what you're detecting
> we don't have access to animal flesh guaranteed to be free of microplastics, do we?
These two assumptions could potentially be at odds.
> And if you use no water at all, it seems like you're missing the entire vector of contamination from acquiring and transporting the water.
I don't have an answer for you for the exact process but I'm also not a scientist working on these experiments. But the people who are doing the experiments are. They know the answers to these questions. A lot of it is going to be detailed in the papers but some won't be because it's more common knowledge among the niche, but you'd likely learn it if you pursued a PhD in the domain
Just so you know, the tone of your comment is extremely off-putting.
I don't have the slightest idea why you're rudely telling me "don't make assumptions", especially if you don't have additional information to add. And the suggestion to "pursue a PhD in the domain" if I want answers is exceedingly obnoxious.
If you don't have helpful answers, you don't need to leave a comment. You don't need to say that you don't have answers but add a bunch of rude sentences while you do it. Better to just not reply at all.
It doesn’t have to be an identical material, just one that has similar properties in attracting and holding contaminants.
> Repeat all steps in exactly the same way, but use distilled water.
But how do you know your source of distilled water isn't also contaminated?
The point is that blank lets you measure that level of "background" contamination, which you then use to correct the measurements made on actual samples.
Suppose you measure around 100 plastic particles per unit in your blank and 1000 in a sample of A. This suggests that A enriches (sheds, etc) microplastic particles. On the other hand, if you found (say) 101 particles/unit in a sample of B, you'd conclude B doesn't do that.
You continue reading the comment and use the other version of a blank
The point isn’t to have 0 microplastics according to the test.
The point of the blank is to identify the base level given the current testing environment. Then you test again with the variable.
If the majority of the microplastics contaminants were introduced in the blank, the variable would show minimal, if any, bump.
I don't believe the point is to construct a blank without them. Rather, the point is to capture what is already there (contaminants) so you can calibrate during the real sample.
Exactly.
If you run a blank and it has no fewer microplastics than the thing you are studying, then that tells you something.
Well, in this case, it tells you that you may have contaminated the sample with your lab setup.
That's EXACTLY what the blanks for! It lets you see what to expect with "All things being the same - just not with the sample in place."
You sure you're a coder?
> Be kind. Don't be snarky. Converse curiously; don't cross-examine. Edit out swipes.
Previously discussed here: https://news.ycombinator.com/item?id=47561711
If lab gloves specifically designed to not contaminate samples are shedding microplactis particules I would expect plastic not designed for this to shed much more micro-plactis particules when it's used.
Are lab gloves specifically designed to not contaminate samples?
That's why gloves are used in scientific research in the first place - to avoid contamination (unless one is working with dangerous substances in which case it's also to protect a person). If they are not fit for purpose that's a problem.
No actually, gloves are used for human comfort first and foremost. A substance does not have to be harmful to people for them not to want to be stained by it; merely keeping fluids off is a huge boon.
We don’t even need to see scientific evidence to see that we’re probably using too much plastic. Most stores and especially supermarkets are full of plastic. Most clothing contains plastics. It’s just hard to avoid even if you want to.
That just means we use plastic a lot.
Whether the balance of how much plastic we use is leaning towards too much depends on the upsides and downsides, and this article is pointing out that one downside we thought was significant is less significant than we thought.
Even if you exclusively buy plastic-free at the store, the ink on the receipt transfers a particularly toxic plastic to your hands.
Small correction: it’s not the ink that is toxic, but the chemicals added as a coating to help the ink develop. Still pretty bad for you though. Some stores have bisphenol free receipts (especially those that are all about natural and plastic-free goods), but they are rare.
And even if you refuse the receipt, the cashier still contaminated your food.
Also, line cooks.
The fact that there's so much microplastics everywhere that it's hard for us to even study tissue in isolate is already not encouraging.
Also the main finding of concern imo in the original Nature paper wasn't the finding that we have a plastic fork-worth of microplastics in our brains. It's the finding that brain tissue seems to concentrate microplastics at a much higher rate than other tissue in the body
I find it concerning that there seems to be such a concerted effort to downplay the significance of that finding
In this case, the lab gloves are shedding materials that superficially resemble microplastics under a microscope but aren't actually microplastics. (I was concerned about that at first too because of the overlap between food service gloves and lab gloves!)
I don't buy the whole premise.
A couple of months ago there were a bunch of news stories, about how maybe oil companies should be sued, just like tobacco companies were.
Then, suddenly out of nowhere, it's actually the gloves that is the problem. It's an excellent counter to such a movement. The scientists are wrong, you see. Microplastics? Overblown!
The average joe will read only the headline/clickbait, and forever doubt microplastics.
If anything I think people who only read the headline will incorrectly assume that gloves are full of microplastics :P
Gloves are full of macroplastics.
Iranian oil is the national security focus now. And Cuba.
Is that finding robust under the possibility that the microplastics in the sample were introduced by the gloves used to handle the sample? One could, for example, explain that result with a hypothesis that the reason there's more microplastics in brain tissue is that they had more hands touch them with lab gloves than the liver and kidney samples.
What are negative consequences attributed to have microplastics, and have to the compare to the risks associated with say drinking alcohol?
Drinking alcohol is probably way worse, but you can choose to not drink, you can't choose to live a normal life and not get microplastics.
Also, alcohol has existed since forever and humans have been drinking it since the beginning of civilization. We have a pretty good idea of what it does and how to keep it under control. Microplastics are a recent thing, it may be a dud, but it may be a serious problem for future generations, so keeping an eye on them is a good thing.
Sure, but the popular news and people concerned about it are generally much closer to hysteria than “keeping an eye on them.”
Which might be the correct answer! Something that's extremely hard to undo should have us much more worried than keeping an eye. We should have tons of research projects running on this.
As for plasticisers common in plastics there's increased risk of premature birth and some other stuff. Also a much higher risk of PCOS (which is why an insane amount of women have it now) and some other stuff among the male offspring.
It's too early to say anything definitive but early research links them to serious risks, including increased risks of heart attacks, stroke, and mortality, alongside potential inflammation, metabolic disruption, and reproductive harm.
https://med.stanford.edu/news/insights/2025/01/microplastics...
> Animal and cellular studies have linked microplastics to biological changes including inflammation, an impaired immune system, deteriorated tissues, altered metabolic function, abnormal organ development, cell damage and more. A recent large-scale review of existing research by scholars at the University of California, San Francisco, concluded that exposure to microplastics is suspected to harm reproductive, digestive and respiratory health and suggested a link to colon and lung cancer.
> More than two years after the procedure, those who had microplastics in their plaque had a higher risk of heart attack, stroke and death than those who didn't.
> So far, his research shows that these plastics can get inside cells and lead to major changes in gene expression. "These findings suggest that the particles contribute to vascular disease progression, emphasizing the urgency of studying their impact," he said.
> Children, whose organs are still developing, could be at higher risk of harm
https://pmc.ncbi.nlm.nih.gov/articles/PMC10151227/
> Thus, chronic exposure to low concentrations of microplastics in the air could be associated with respiratory and cardiovascular diseases depending on an individual’s susceptibility and the particle characteristics.
> The results of cellular and animal experiments have shown that microplastics can affect various systems in the human body, including the digestive, respiratory, endocrine, reproductive, and immune systems.
> In addition, microplastics interfere with the production, release, transport, metabolism, and elimination of hormones, which can cause endocrine disruption and lead to various endocrine disorders, including metabolic disorders, developmental disorders, and even reproductive disorders (i.e., infertility, miscarriage, and congenital malformations)
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The "compared to drinking alcohol" bit feels like bait and I won't engage. They are two completely different risk factors. For one, alcohol doesn't concentrate in brain tissue.
It's the finding that brain tissue seems to concentrate microplastics at a much higher rate than other tissue in the body
If I remember correctly, the method they used to detect microplastics, which involves pyrolysis, gives much the same result for lipids (which brain tissue has a lot of) as pure hydrocarbon plastics like PE and PP, because they all feature relatively long hydrocarbon chains and the pyrolysis products will contain the same short-chain hydrocarbons.
I find it concerning that there seems to be such a concerted effort to downplay the significance of that finding
There is nothing to be concerned about. This is just the (re)discovery of basic chemistry and the natural response to misguided alarmism.
Before I ask, I want to disavow any suspicions people may have that I'm a shill for asking, so to borrow from a related subject: I hate the idea of bioaccumulative toxins. 3M and DuPont executives behind not just the original per- and polyfluorinated chemicals, but the replacements like GenX that are basically a nearly identical molecule with just a few atoms changed belong in prison, not in boardrooms, to say nothing of all the people complicit in distributing them in consumer products.
I may have taken the bait from the plastics industry on this one, I really don't know, but wasn't one of the pushbacks something along the lines of "well yes, there are microplastics, and yes, they do accumulate in the body, but you shouldn't worry about it - there isn't really any evidence of systemic harm being caused by them"?
Do you know if there are studies that do show evidence of harm from microplastic accumulation? It sounds really bad at face value, but I still want good, hard evidence before I'm ready to add an industry to my personal list of perpetrators of crimes against humanity.
I'll repost from a different comment I left:
---
Early research links them to serious risks, including increased risks of heart attacks, stroke, and mortality, alongside potential inflammation, metabolic disruption, and reproductive harm.
https://med.stanford.edu/news/insights/2025/01/microplastics...
> Animal and cellular studies have linked microplastics to biological changes including inflammation, an impaired immune system, deteriorated tissues, altered metabolic function, abnormal organ development, cell damage and more. A recent large-scale review of existing research by scholars at the University of California, San Francisco, concluded that exposure to microplastics is suspected to harm reproductive, digestive and respiratory health and suggested a link to colon and lung cancer.
> More than two years after the procedure, those who had microplastics in their plaque had a higher risk of heart attack, stroke and death than those who didn't.
> So far, his research shows that these plastics can get inside cells and lead to major changes in gene expression. "These findings suggest that the particles contribute to vascular disease progression, emphasizing the urgency of studying their impact," he said.
> Children, whose organs are still developing, could be at higher risk of harm
https://pmc.ncbi.nlm.nih.gov/articles/PMC10151227/
> Thus, chronic exposure to low concentrations of microplastics in the air could be associated with respiratory and cardiovascular diseases depending on an individual’s susceptibility and the particle characteristics.
> The results of cellular and animal experiments have shown that microplastics can affect various systems in the human body, including the digestive, respiratory, endocrine, reproductive, and immune systems.
> In addition, microplastics interfere with the production, release, transport, metabolism, and elimination of hormones, which can cause endocrine disruption and lead to various endocrine disorders, including metabolic disorders, developmental disorders, and even reproductive disorders (i.e., infertility, miscarriage, and congenital malformations)
I'm late responding, but why no backscattered electron images from the SEMs?
The micropastics should have a really low average Z, I think the stearates will be much higher and distinguishable in a BSE image, and (not to mention if you observe their x-ray spectrum...)
So I'm either confused about something or pointing out that they're hard to distinguish in an SE image is not really a useful point, ... it's more relevant that SEM isn't the typical tool used for these counting efforts.
I'd look myself but I recently moved and the SEM is in parts. :)
Someone needs to analyze samples which can't be contaminated. Like samples from an asteroid. As I know, for a couple of years ago there was a delivery from one.