I'm amazed that wasn't taken into account! Many years ago, in the final year of my Biology degree, I did a paid summer internship at an Evolutionary Biology lab here in Spain, assisting in a project where they were researching relationships between metal ion accumulation (mostly zinc) and certain SNPs (≈"gene varieties"). A lot of my work was in slicing tiny fragments of deep-frozen human livers and kidneys in a biosafety cabinet over dry ice.
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.
> single-use plastic that is involved in biological research
The samples were not contaminated by plastic in the gloves. Latex gloves don't contain plastic, they're made from natural rubber. Nitrile gloves also don't contain plastic, although they're very similar to plastic.
The contamination that this study found wasn't microplastic contamination. The gloves weren't adding microplastics. The gloves were adding stearates, which aren't plastic, but look like microplastic in many of the methods for measuring microplastics.
You found a paper saying that contamination is possible. That doesn’t mean that most of these plastic studies are doing the necessary controls, let alone the (almost impossible) task of preventing the contamination in a laboratory setting where nanomolar detection levels are used to make broad claims.
Are more “controls” what is necessary here? The problem wasn’t plastic contamination, it was the presence of stearates. Distinguishing between stearates and microplastics sounds like a classification problem, not a control problem.
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.
Many papers in this field are missing obvious controls, but you’re correct that controls alone are insufficient to solve this problem.
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.
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]
granted, I feel like maybe a review of lab equipment regularly is not a bad idea. in my low level undergraduate summer job, we realized all the stuff I did in those 3 months were moot at the end because I end up running some blanks on the pipetting robot and discovered that some glitch resulted in progressively less material being pipetted towards the end of the tray vs. the beginning....
>>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
What boggles the mind is you commenting on an article you clearly did not read...stating something that is not there...
The various "OMG MICROPLASTICS" studies always smacked of alarmism. No one has actually identified tangible harms from microplastics; it's just taken as a given that they are bad. So this fueled a bunch of studies that tried to find them everywhere. Even the authors of this study go to great pains to not challenge the dogma that microplastics are existentially terrifying. So I fully expect we'll still be panicking over vague, undefined harm whenever we find microplastics somewhere.
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.
I guess with Raman I can see this being misidentified but I do testing with FTIR at my job, although not often for microplastics and we often detect olefins and stearates and they don't seem to get confused. I didn't realize there were stearates on nitrile gloves, we'll need to be more careful of that. We are always weary of protein contamination from people, or cellulose/nylon from clothing.
The way this study was done makes perfect sense for finding this cross-contamination issue, but does not actually address how microplastics samples are extracted and found in sampling studies.
The below meta-study largely discusses sampling methods and protection from cross contamination so everyone here acting like this one study’s somehow invalidates decades of quality research:
>Due to the wide contamination of the environment with microplastics, including air [29], measures should be taken during sampling to reduce the contamination with these particles and fibers. The five rules to reduce cross-contamination of microplastic samples are: (1) using glass and metal equipment instead of plastics, which can introduce contamination; (2) avoiding the use of synthetic textiles during sampling or sample handling, preferring the use of 100% cotton lab coat; (3) cleaning the surfaces with 70% ethanol and paper towels, washing the equipment with acid followed by ultrapure water, using consumables directly from packaging and filtering all working solutions; (4) using open petri dishes, procedural blanks and replicates to control for airborne contamination; (5) keeping samples covered as much as possible and handling them in clean rooms with controlled air circulation, limited access (e.g. doors and windows closed) and limited circulation, preferentially in a fume hood or algae-culturing unit, or by covering the equipment during handling [15], [26], [95], [105], [107]. A fume hood can reduce 50% of the contamination [105] while covering samples during filtration, digestion and visual identification can reduce more than 90% of contamination [95].
So don’t ghost ride the whip about the death of the microplastic plague just yet.
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.
"Chemically very similar", as in "contains long hydrocarbon chains", something which even all biological matter (lipids) has. I've looked at a few microplastic studies and many of them use pyrolysis and mass spectroscopy to detect their presence, which is going to show almost the same results for animal fat as pure hydrocarbon plastics like PE (the most common plastic by production volume) and PP.
Studies are extremely difficult to get right. I'm generally a little bit skeptical of data for this reason.
A bit of a tangent but still on the subject of environmental pollution; the other day I found out that CO2 sensor sensitivity naturally drifts over time... So when a CO2 sensor is replaced for long term climate research, if they try to calibrate the new sensor to the old one at the time of replacement, the drift would be carried over into the new sensor even if no actual real change of CO2 occurred... Apparently there are standards to prevent this but mistakes have been identified multiple times with the methodology for setting that standard... Anyway measuring data accurately is really hard.
"The researchers used air samplers which are fitted with a metal substrate. Air passes through the sampler, and particles from the atmosphere deposit onto the substrate. Then, using light-based spectroscopy, the researchers are able to determine what kind of particles are found on the substrate.
Clough prepared the substrates while wearing nitrile gloves, which is recommended by the guidance of literature in the microplastics field. But when she examined the substrates to estimate how many microplastics she captured, the results were many thousands of times greater than what she expected to find."
------------------
The very first thing that should have been done is to run results for a substrate that hadn't been placed in the sampler. You need to know what a zero result looks like just to characterize your setup. You'd also want to run samples with known and controlled micro-plastic concentrations. Why didn't they do this? Their results are utterly meaningless if they didn't.
From the study in the OP you cannot derive that current studies on microplastics are not valid. The headline framing that scientists have been measuring their own gloves, is science journalism doing what it does best...
Stearates are water soluble soaps, so any study using standard wet chemistry extraction, and that is most of them, washes them away before analysis even begins. Stearates also cant mimic polystyrene, PET, PVC, nylon, or any of the dozens of other polymers routinely found in environmental and human tissue samples.
Didnt they use for newest studies to detect microplastic in placentas I think only non plastic omitting alternative gloves and material. Can't recall there it was specifically mentioned in a worldclass ARTE docu about microplastics maybe some ARTE Ultras here can recall.
I once worked in a meatball factory. I touched almost every single meatball with nitrile gloves. There's probably a lot of earlier process steps where humans are touching the food with gloves.
I had always assumed there was a methodological failure that kept getting replicated. There were enough articles like "scientists find microplastics at bottom of peat bog" that really made me dubious of the claims.
"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.
Also consider how many people have to wear them every day or close to. How much they interact with food and packages that most of us eventually touch. Food for thought.
this feels like such a weird oversight in such a controlled environment: "oh my bad it was the gloves!"
I wonder in how many other studies this happened?
Decades ago the only modern disposable gloves like these were "natural" latex which served medical professionals well but were miserably inadequate for chemical use. So nobody even thought about using them with aggressive industrial materials.
Nitrile emerged only as a specialty alternative to some of the earlier synthetic chemical-resistant compounds.
They were not disposable, more expensive than the earlier synthetic compounds, also not as thick a glove was needed so they gave you protection that was never available from anything but a much more clumsy alternative. Not nearly as tactile as the disposables though, that is their big redeeming feature.
One of the major weak points of nitrile is acetone, and things like MEK or ethyl acetate, which will soak into the polymer, swell, and weaken it. If you don't let them get too weak and shred them, they will shrink back after they dry out and are still fairly OK after that But nitrile is much better against most other solvents, acids, and alkalis though. Chlorinated solvents can be kind of rough too.
I was often the first one to use nitrile in some facilities, these ended up taking over and were the typical turquoise non-disposable ones that go about halfway up the forearm. Not the skin-tight "student models" that so many people use today. Now available in various colors :)
But these early "green" gloves alone were the same ones contributing to the stereotypical look of an environmental worker, where they can be even more scary when they sometimes add a complete tyvek suit with boots, hood, respirator, and the gloves with rubber bands around the sleeves, sampling the river water while you are fishing downstream :(
The ones like we used are $16 a pair now and were never cheap enough to be disposable. They actually last many months though. Only one other old guy uses them when I go back to my old lab, everyone else was "trained" on disposables now, each lab has a wall-mounted dispenser of various sizes like they have in hospitals. The "cost savings" are so well-realized so long ago that nobody knows it's completely false :\ People go through them like water, and it's still a shitshow when they try not to.
It's really worse from a contamination standpoint because people will still wear them for an hour or two during various chemical-handling events, but also do a little paperwork or keyboard typing with the gloves on, plus doorknobs and cabinet handles they are touching are much riskier than it used to be when disposables were not an option. Just because it's such a drag to peel them off and put on a new pair 10 minutes later.
Before disposables arrived, we used to have slightly oversized non-disposables, and throw them on & off & on many times per day, I still do. Plus I often wash the gloves while wearing them not much differently than washing my bare hands, mainly to get rid of chemicals using (very) hot soap & water or even using other strong solvents like heptane to rinse off heavier chemicals and oils. Probably about as particle-free as you can get except for what is floating around in the ambient air. Not like the skin-tight almost too-thin gloves people settle for now where they need to be peeled back off inside-out and thrown away each time.
By this point in the 21st century there are dedicated representatives of the glove manufacturers making high-touch sales calls, so there have got to be some bonuses that didn't exist that many decades ago.
> To be honest, after reading some of these microplastics papers I'm starting to suspect most of them are bullshit. Plastics are everywhere in a modern lab and rarely do these papers have proper controls, which I suspect would show that there is a baseline level of microplastic contamination in labs that is unavoidable. Petri dishes, pipettes, microplates, EVERYTHING is plastic, packaged in plastic, and cleaned using plastic tools, all by people wearing tons of synthetic fibers.
> We went through this same nonsense when genetic sequencers first became available until people got it into their heads that DNA contamination was everywhere and that we had to be really careful with sample collection and statistical methods. [1]
So the problem is these particles are literally flying off the gloves of the scientists wearing them to the point it's interfering with the experiment and so... it's less of a problem?
That's a relief. Now I can stop worrying about microplastics. Just like the environment - we don't hear much about it any more, so they must have sorted that out too. Didn't they? Did they?
Carl Sagan was right all along. Always question science, never trust these so called experts, do your own assessment, research and thinking. This must be another global climate change scam.
265 comments
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.
> single-use plastic that is involved in biological research
The samples were not contaminated by plastic in the gloves. Latex gloves don't contain plastic, they're made from natural rubber. Nitrile gloves also don't contain plastic, although they're very similar to plastic.
The contamination that this study found wasn't microplastic contamination. The gloves weren't adding microplastics. The gloves were adding stearates, which aren't plastic, but look like microplastic in many of the methods for measuring microplastics.
>> I'm amazed that wasn't taken into account!
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.
> "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...
>> That doesn’t mean that most of these plastic studies are doing the necessary controls
That was never my argument. Read it again.
>>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
What boggles the mind is you commenting on an article you clearly did not read...stating something that is not there...
> I'm amazed that wasn't taken into account!
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 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.
The below meta-study largely discusses sampling methods and protection from cross contamination so everyone here acting like this one study’s somehow invalidates decades of quality research:
>Due to the wide contamination of the environment with microplastics, including air [29], measures should be taken during sampling to reduce the contamination with these particles and fibers. The five rules to reduce cross-contamination of microplastic samples are: (1) using glass and metal equipment instead of plastics, which can introduce contamination; (2) avoiding the use of synthetic textiles during sampling or sample handling, preferring the use of 100% cotton lab coat; (3) cleaning the surfaces with 70% ethanol and paper towels, washing the equipment with acid followed by ultrapure water, using consumables directly from packaging and filtering all working solutions; (4) using open petri dishes, procedural blanks and replicates to control for airborne contamination; (5) keeping samples covered as much as possible and handling them in clean rooms with controlled air circulation, limited access (e.g. doors and windows closed) and limited circulation, preferentially in a fume hood or algae-culturing unit, or by covering the equipment during handling [15], [26], [95], [105], [107]. A fume hood can reduce 50% of the contamination [105] while covering samples during filtration, digestion and visual identification can reduce more than 90% of contamination [95].
So don’t ghost ride the whip about the death of the microplastic plague just yet.
https://www.sciencedirect.com/science/article/pii/S016599361...
"Chemically very similar", as in "contains long hydrocarbon chains", something which even all biological matter (lipids) has. I've looked at a few microplastic studies and many of them use pyrolysis and mass spectroscopy to detect their presence, which is going to show almost the same results for animal fat as pure hydrocarbon plastics like PE (the most common plastic by production volume) and PP.
A bit of a tangent but still on the subject of environmental pollution; the other day I found out that CO2 sensor sensitivity naturally drifts over time... So when a CO2 sensor is replaced for long term climate research, if they try to calibrate the new sensor to the old one at the time of replacement, the drift would be carried over into the new sensor even if no actual real change of CO2 occurred... Apparently there are standards to prevent this but mistakes have been identified multiple times with the methodology for setting that standard... Anyway measuring data accurately is really hard.
People do not appreciate correctness enough.
Keeping things meticulously clean on the microscopic level is a complicated task. One of the many reasons why so few EUV chip fabs even exist.
Clough prepared the substrates while wearing nitrile gloves, which is recommended by the guidance of literature in the microplastics field. But when she examined the substrates to estimate how many microplastics she captured, the results were many thousands of times greater than what she expected to find."
------------------
The very first thing that should have been done is to run results for a substrate that hadn't been placed in the sampler. You need to know what a zero result looks like just to characterize your setup. You'd also want to run samples with known and controlled micro-plastic concentrations. Why didn't they do this? Their results are utterly meaningless if they didn't.
"When Good Intentions Go Bad — False Positive Microplastic Detection Caused by Disposable Gloves" - https://pubs.acs.org/doi/10.1021/acs.est.0c03742
From the study in the OP you cannot derive that current studies on microplastics are not valid. The headline framing that scientists have been measuring their own gloves, is science journalism doing what it does best...
Stearates are water soluble soaps, so any study using standard wet chemistry extraction, and that is most of them, washes them away before analysis even begins. Stearates also cant mimic polystyrene, PET, PVC, nylon, or any of the dozens of other polymers routinely found in environmental and human tissue samples.
Nothing to see here.
"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.
they tracked levels of plastic-related chemicals and fertility markers. after plastic detox 3 out of 6 couples got pregnant.
the whole research process methodology, not just measurement, miss critical assessment
How could you possibly know your analytical technique was valid if you don’t run a blank to see?
Nitrile emerged only as a specialty alternative to some of the earlier synthetic chemical-resistant compounds.
They were not disposable, more expensive than the earlier synthetic compounds, also not as thick a glove was needed so they gave you protection that was never available from anything but a much more clumsy alternative. Not nearly as tactile as the disposables though, that is their big redeeming feature.
One of the major weak points of nitrile is acetone, and things like MEK or ethyl acetate, which will soak into the polymer, swell, and weaken it. If you don't let them get too weak and shred them, they will shrink back after they dry out and are still fairly OK after that But nitrile is much better against most other solvents, acids, and alkalis though. Chlorinated solvents can be kind of rough too.
I was often the first one to use nitrile in some facilities, these ended up taking over and were the typical turquoise non-disposable ones that go about halfway up the forearm. Not the skin-tight "student models" that so many people use today. Now available in various colors :)
But these early "green" gloves alone were the same ones contributing to the stereotypical look of an environmental worker, where they can be even more scary when they sometimes add a complete tyvek suit with boots, hood, respirator, and the gloves with rubber bands around the sleeves, sampling the river water while you are fishing downstream :(
The ones like we used are $16 a pair now and were never cheap enough to be disposable. They actually last many months though. Only one other old guy uses them when I go back to my old lab, everyone else was "trained" on disposables now, each lab has a wall-mounted dispenser of various sizes like they have in hospitals. The "cost savings" are so well-realized so long ago that nobody knows it's completely false :\ People go through them like water, and it's still a shitshow when they try not to.
It's really worse from a contamination standpoint because people will still wear them for an hour or two during various chemical-handling events, but also do a little paperwork or keyboard typing with the gloves on, plus doorknobs and cabinet handles they are touching are much riskier than it used to be when disposables were not an option. Just because it's such a drag to peel them off and put on a new pair 10 minutes later.
Before disposables arrived, we used to have slightly oversized non-disposables, and throw them on & off & on many times per day, I still do. Plus I often wash the gloves while wearing them not much differently than washing my bare hands, mainly to get rid of chemicals using (very) hot soap & water or even using other strong solvents like heptane to rinse off heavier chemicals and oils. Probably about as particle-free as you can get except for what is floating around in the ambient air. Not like the skin-tight almost too-thin gloves people settle for now where they need to be peeled back off inside-out and thrown away each time.
By this point in the 21st century there are dedicated representatives of the glove manufacturers making high-touch sales calls, so there have got to be some bonuses that didn't exist that many decades ago.
> To be honest, after reading some of these microplastics papers I'm starting to suspect most of them are bullshit. Plastics are everywhere in a modern lab and rarely do these papers have proper controls, which I suspect would show that there is a baseline level of microplastic contamination in labs that is unavoidable. Petri dishes, pipettes, microplates, EVERYTHING is plastic, packaged in plastic, and cleaned using plastic tools, all by people wearing tons of synthetic fibers.
> We went through this same nonsense when genetic sequencers first became available until people got it into their heads that DNA contamination was everywhere and that we had to be really careful with sample collection and statistical methods. [1]
[1] https://news.ycombinator.com/item?id=40681390