Posted by giuliomagnifico 9 hours ago
The reason I bring this up is because the researchers had taken the essential precaution of providing me with a ceramic knife to do the cutting (and platic pliers), to eliminate the risk of contaminating the samples with metal from ordinary cutting implements.
That some research on microplatics did not take into account the absolutely mental amount of single-use plastic that is involved in biological research, particularly gloves of all things, boggles the mind.
Agreed. While I didn’t anticipate this myself, nor would have likely figured it out myself, I also don’t expect my claims to influence global policy.
The scientists who failed to realize this do expect that, so the standards we expect from them need to be higher in accordance with that.
This was taken into account: https://news.ycombinator.com/item?id=47563392
There is practically universal recognition among microplastics researchers that contamination is possible and that strong quality controls are needed, and to be transparent and reproducible, they have a habit of documenting their methodology. Many papers and discussions suggest avoiding all plastics as part of the methodology, e.g. “Do’s and don’ts of microplastic research: a comprehensive guide” https://www.oaepublish.com/articles/wecn.2023.61
Another thing to consider is that papers generally compare against baseline/control samples, and overestimating microplastics in baseline samples may lead to a lower ratio of reported microplastics in the test samples, not higher.
When you are taking measurements at the detection limit of any molecule that is widespread in the environment, you are going to have a difficult time of distinguishing signal from background. This requires sampling and replication and rigorous application of statistical inference.
> Another thing to consider is that papers generally compare against baseline/control samples,
Right, that’s what a control is.
> and overestimating microplastics in baseline samples may lead to a lower ratio of reported microplastics in the test samples, not higher.
There’s no such thing as “overestimating in baseline samples”, unless you’re just doing a different measurement entirely.
What you’re trying to say is that if there’s a chemical everywhere, the prevalence makes it harder to claim that small measurement differences in the “treatment” arm are significant. This is a feature, not a bug.
> There’s no such thing as “overestimating in baseline samples”
What do you mean? Contamination and mis-measurement of control samples is a thing that actually happens all the time, and invalidates experiments when discovered.
> What you’re trying to say is that if there’s a chemical everywhere, the prevalence makes it harder to claim that small measurement differences in the “treatment” arm are significant.
No. What I was trying to say is that if the control is either mis-measured, for example by accidentally counting stearates as microplastics, or contaminated, then the summary outcome may underestimate or understate the prevalence of microplastics in the test sample, even though the measurement over-estimated it.
That was never my argument. Read it again.
> "You found a paper"
johnbarron didn't find it. The authors cited it as foundational to their own work. it's ref. 38 in the paper under discussion. From the paper: "this finding had not been reported in the MP literature until 2020, when Witzig et al. reported that laboratory gloves submerged in water leached residues that were misidentified as polyethylene."[1]
> "most of these plastic studies are [not] doing the necessary controls"
which studies? The paper they linked surveys 26 QA/QC review articles[1]. Seems well understood.
> "a laboratory setting where nanomolar detection levels are used to make broad claims"
This is like saying "miles per gallon" when discussing weight. "nanomolar detection levels"...microplastics are individual particles identified by spectroscopy, reported as particles per mm^2. "Nanomolar" is a dissolved-species concentration unit. It has nothing to do with particle counting. (I, and other laymen, understand what you mean but you go on later in the thread to justify your unsourced and unjustified claims here via your subject-matter expertise.)
> "(almost impossible) task of preventing the contamination"
The paper provides open-access spectral libraries and conformal prediction workflows to identify and subtract stearate false positives from existing datasets[1]. Prevention isn't the strategy. Correction is. That's the entire point of the paper they linked and the follow-up in [2]
[1] https://pubs.rsc.org/en/content/articlehtml/2026/ay/d5ay0180...
[2] https://news.umich.edu/nitrile-and-latex-gloves-may-cause-ov...
This paper used “light-based spectroscopy” [1]. Many others use methods that depend on gas chromatography or NMR. A relatively infamous recent example used pyrolysis GCMS to make low-concentration measurements (hence: nanomolar), which they credulously scaled up by some huge factor, and then made idiotic claims about plastic spoons in brains.
Relatively little quantitative science in this area depends on counting plastic particles in microscopic images, but it’s what gets headlines, because laypeople understand pictures.
[1] as an aside, the choice of terminology here is noteworthy. A simple visual light absorption spectra is also “light based spectroscopy”, but is measuring the aggregate response of a sample of a heterogeneous mixture, and is conventionally converted to molar equivalents via some sort of calibration curve (otherwise you can’t conclude anything). But there could be other approaches that are closer to microscopy, which they also discuss. “Particles per square millimeter” is also a unit of concentration (albeit a shitty one, unless your particles are of uniform mass).
Anyway, the point is that these kinds of quantitative analyses are all trying to do measurements that are fundamentally about concentration, which is why I chose the words that I did.
"1 nanomole of polyethylene" requires you to pick an arbitrary average molecular weight.
This changes the answer by orders of magnitude depending on what you pick.
Which is why nobody does it.
> Relatively little quantitative science in this area depends on counting plastic particles in microscopic images...Many others use methods that depend on gas chromatography or NMR.
So we're dismissive of some subset of papers, because they get false positives using toy methods.
Real science would use gas chromatography.
But...the paper we're dismissing tested gas chromatography. And found the same false positive. [1, in abstract]
> A relatively infamous recent example used pyrolysis GCMS to make low-concentration measurements (hence: nanomolar)
The brain study I'm guessing you are referring to, [2], measured low concentrations, yes.
But it reported them in ug/g.
Because polymers don't have a defined molecular weight.
> made idiotic claims about plastic spoons in brains
The brain study I'm guessing you are referring to, [2], does not mention spoons, or, come close.
Are we sure there's a paper that did that?
[1] Witzig et al, https://pubs.acs.org/doi/10.1021/acs.est.0c03742, "Therefore, u-Raman, u-FTIR, and pyr-GC/MS were further tested for their capability to distinguish among PE, sodium dodecyl sulfate, and stearates. It became clear that stearates and sodium dodecyl sulfates can cause substantial overestimation of PE."
[2] Campen et al, https://pubmed.ncbi.nlm.nih.gov/38765967/, "Bioaccumulation of Microplastics in Decedent Human Brains"
"I have unique insight as a non-expert that all experts miss and the entire field is blind to" -> usually nonsense
"I think in this specific instance academically qualified people are missing something that's obvious to me" -> often true.
"Nanomolar" is a dissolved-species concentration unit. It doesn't apply to spectroscopic particle counting.
Been here 16 years, it's always an adventure seeing whether stuff like this falls into:
A) Polite interest that doesn't turn into self-keyword-association
B) Science journalism bad
C) Can you believe no one else knows what they're doing.
(A) almost never happens, has to avoid being top 10 on front page and/or be early morning/late night for North America and Europe. (i.e. most of the audience)
(B) is reserved for physics and math.
(C) is default leftover.
Weekends are horrible because you'll get a "harshin' the vibe" penalty if you push back at all. People will pick at your link but not the main one and treat you like you're argumentative. (i.e. 'you're taking things too seriously' but a thoughtful person's version)
I used to be a code monkey, I wrote systems software at megacorps, and still can't understand why so many programmers irresponsibly write memory unsafe code given it has a global impact.
So Poe's law applies here.
(to go a bit further, in case it's confusing: both you and I agree on "why do people opt-in to memunsafe code in 2026? There’s no reason to" - yet, we also understand why Linux/Android/Windows/macOS/ffmpeg/ls aren't 100% $INSERT_MEM_SAFE_LANGUAGE yet, and in fact, most new written for them is memunsafe)
Creating a user interface for the world’s knowledge doesn’t make the developer an expert on the knowledge that the interface holds in its database. Regardless of how sophisticated that interface might be.
What boggles the mind is you commenting on an article you clearly did not read...stating something that is not there...
The Bay Harbor Butcheress[0] :)
[0]: https://en.wiktionary.org/wiki/butcheress (at First I made it as a joke but turns out that butcheress is a real term, indeed)
There is a “case files” podcast on it that I found quite good.
https://casefilepodcast.com/case-178-the-woman-without-a-fac...
The only connection between the crimes was the presence of DNA from a single female, which had been recovered from 40 crime scenes, ranging from murders to burglaries. In late March 2009, investigators concluded that there was no "phantom criminal", and the DNA had already been present on the cotton swabs used for collecting DNA samples; it belonged to a woman who worked at the factory where they were made.
At worst, I'd expect to see people disregarding the threat, not disregarding the presence of the microplastics themselves.
On the other hand I suspect much of the real science on environmental plastic might avoid the term microplastic since it seems to have a meaning that flows to whatever can make the scariest headline today. I have seen the size range to qualify run from microscopic up to a couple of millimetres. Volumes, quantities, or location stated without regard to individual particle size. I'm relatively certain that they have not discovered 1mm particles inside red blood cells.
Even what counts as a plastic seems to be an easy way of adding vagueness, I saw one table that seemed to count cellulose as a plastic, which makes sense if you are thinking about properties of the material, but unsurprisingly easy to come across that it's not really worth going looking for it.
This type of research requires very little creativity or study design -- just throw a dart in a room and try and find microplastics in whatever it lands on. Boom, you get a grant for your study, and journalists will cover your result because it gets clicks. Whenever this type of incentive exists, we should be very skeptical of a rapidly-emerging consensus.
If it's true that microplastics are everywhere and in everything (which maybe that's now not actually the case), even a very small chance that there's some serious harm we're not aware of should be taken extremely seriously, because at this point there's (apparently) no practical way to avoid or get away from them, or to even stop producing them. And since they're such a new phenomenon in these quantities, we haven't really had the time to really drill down and figure out *if* there are longterm negative effects.
IMO, we should be intellectually humble about our lack of knowledge on these microplastics, and part of that humility should involve being cautious about introducing them to our bodies and environment.
What does that look like today, pragmatically speaking?
https://www.ehn.org/toxic-tire-chemicals-threaten-salmon-as-...
Just because you as a single consumer may not seem impacted by microplastics does not mean it's alarmism to suggest that it's a really bad phenomenon.
What great pains are they going through? The study is a discussion of measurement techniques and makes no comment on whether they are harmful because that’s irrelevant to the paper.
This could just as easily be a paper on how wearing the wrong type of gloves results in overestimating calcium in soil. You’re the one injecting a political agenda.
>This type of research requires very little creativity or study design -- just throw a dart in a room and try and find microplastics in whatever it lands on. Boom, you get a grant for your study
Precisely, and mapping of that kind is entirely valid and required in huge amounts to have the full picture. Somebody has to do the grunt work.
No way this isn't heavily studies by now.
Edit: found a whole meta-study in like 30 seconds of searching: https://www.frontiersin.org/journals/public-health/articles/...
Hey remember what happened with BPA? That was frustrating. We saw ostensibly legitimate concern, then manufacturers telling us they got rid of it. Maybe it would’ve inspired confidence if the removal adverts came with data sheets on the replacement chemicals.
Just like BPA, BPS is an endocrine disruptor. The idea that it's less harmful than BPA is mostly due to lack of research.
Unlike bare skin, you can't really feel when your gloves are contaminated. So you are less likely to replace gloves when you should. With bare hands, you can feel the raw chicken juices on you, so it's pretty natural to want to wash your hands right after handling the raw chicken.
Gloves are important in medicine, but that's with proper use where doctors and nurses put on new gloves for every patient. That doesn't always happen.
To the contrary. You take off and throw out your gloves every time you finish doing something with raw meat. It's procedure. It's habit.
You're never relying on "feel" to determine whether there are "raw chicken juices on you". Using "feel" is not reliable.
I don't know why you think food service workers aren't constantly putting on new gloves, but doctors and nurses are. Like, if you're cutting up chicken for an hour you're not, but if you're moving from chicken to veggies you absolutely are.
I've seen enough absent-minded nose wipes on the back of gloves at Chipotle-style establishments to be pretty OK with this take.
And that's where people are watching.
I think that because I was a food service worker and it's impossible to change gloves during a rush. Nitrile gloves and sweaty hands simply do not mix. There are also many more forms of cross contamination than just raw meat to cooked food.
But they don't generally require them to replace gloves between batches of (the same kind of) meat, or between different kinds of vegetables, or when switching from vegetables to meat, or between customers if they're on a service line. While it's recommended in those situations, I'm not sure any state mandates it.
You are supposed to. I've seen plenty of fast food places where the gloves stay on between jobs.
I'm sure there are upscale places that are better on this point.
> You're never relying on "feel" to determine whether there are "raw chicken juices on you". Using "feel" is not reliable.
If you were just working with raw chicken, that slimy feeling on your skin is a pretty good motivator for most people to immediately wash their hands. It's more than just procedure or habit, your hands feel dirty and you want to wash that off.
> I don't know why you think food service workers aren't constantly putting on new gloves, but doctors and nurses are. Like, if you're cutting up chicken for an hour you're not, but if you're moving from chicken to veggies you absolutely are.
You absolutely are supposed to. But there's a gap in what you are supposed to do vs what actually happens in practice. Especially if you get a penny pinching boss that doesn't like wasting money on gloves.
That doesn't happen so much in medicine because the consequences are much higher. But for food? Not uncommon. There are more than a few restaurants with open kitchens that I've had to stop eating at because employees could be seen handling a bunch of things with the same set of gloves on.
It also does not help that food is often a mad rush.
And it's true that you would get cleaner food prep if you used gloves properly. However, that requires a lot of gloves getting thrown away.
I’ve never seen for example sushi portrayed with anything but bare hands
“ Stearates are salts, or soap-like particles. Manufacturers coat disposable gloves with stearates to make them easier to peel from the molds used to form them. But stearates are also chemically very similar to some microplastics, according to the researchers, and can lead to false positives when researchers are looking for microplastic pollution.”
Stearates aren’t microplastics. Maybe we need to be concerned with stearate pollution too.
We’ve reached the absurd point where all sides of the political spectrum have sacred cows, and an exceedingly poor understanding of scientific reasoning, and all sides also try to dunk on the others by claiming scientific authority.
I mean, I get the instinct that foreign-entity can't exactly be good for me, but the same instinct applied to GMOs, and as far as I know organic foods have never yielded any sort of statistically visible health impacts.
Plastics earn their keep in general by being non-reactive and 'durable', so it's not entirely shocking if they can pass through (or hang around inside) the body without engaging in a lot of biochemical activity.
I'd also consider plastic, and their additives, to be a lot bigger and longer lasting unknown than GMOs.
I have seen zero evidence that they are bad in very small quantities, but the dose can make the poison and they are out there in increasingly alarming quantities.
More like flippancy, even hubris.
The approach you advocate is essentially the EU's precautionary principle. [1]
[1] https://eur-lex.europa.eu/EN/legal-content/summary/the-preca...
Even if plastics of all sizes are 100% biologically inert, they're still a Trojan Horse for other toxins.
https://www.sciencedirect.com/science/article/pii/S030438942...
https://www.researchgate.net/profile/Verla-Wirnkor-2/publica...
Roughly 50% of indoor dust is composed of microplastics, so it's not like it's uncommon.
I highly doubt that. Soil, skin and pollen are usually the big ones. Hairs depending one how you count dust, but eliminating hair like fibres would also eliminate most of the sources of plastic, unless you allow really large particle sizes.
[edit] Checking research. The highest claim I found was 39% of fibres (in household dust, Japan). but that seemed to be per particle not by volume.
>eliminating hair like fibres would also eliminate most of the sources of plastic
If you allow fibres they'd be 0.01% of fibres if you've got a dog anything like mine.
Genuine question: we used to simply wash our hands well before preparing food.
At what point did the wearing of disposable gloves become "better"?
"Strong claims require strong evidence". Somehow it happens pretty regularly in academia that only one method becomes acceptable and any conflicting results get herded out on technical grounds.
With what chemical structure, even? That should have been the first red flag.