A Big Panic Over Tiny Plastics
Science can detect increasingly small particles of plastic in our air and water. That doesn't mean it's bad for you.

A study published in the Proceedings of the National Academy of Sciences (PNAS) in January has been used for a media wave of scaremongering about plastic residue in bottled water. Its results are based on a system developed by researchers at Columbia University and Rutgers University that uses a "hyperspectral stimulated Raman scattering (SRS) imaging platform with an automated plastic identification algorithm that allows micro-nano plastic analysis." That sounds impressive, and it really is, relying on an immersive tank, lasers, and advanced computational techniques.
The study's major contribution to science was actually not in coming up with an estimate of the amount of plastic in bottled water, but in inventing a technique that could detect nanoplastics at all. Nanoplastics, as the name implies, are much smaller than already tiny microplastics. Microplastics can be as small as one micron in size, 1/83rd the width of a strand of hair.
The smallest-sized particles the researchers picked up measured 100 nanometers. This means we can now detect bits of plastic so small that 10 million of them would amount to a piece of microplastic a fraction of the width of a hair.
Just as a stronger telescope will discover more planets, or a better microscope might tell us there are more bacteria in a petri dish than we previously knew, so too did this impressive newfound ability to see infinitesimally small bits of plastic mean that they discovered a seemingly infinite amount of plastic.
Nearly every news outlet hit concerned thirsty Americans with headlines such as "Scientists Find About a Quarter Million Invisible Nanoplastic Particles in a Liter of Bottled Water" (Associated Press) and "Bottled water contains hundreds of thousands of potentially dangerous plastic fragments: Study" (The Hill), as if the 240,000 figure is directly meaningful to their readers.
The number of pieces of plastic, as opposed to the amount of plastic, is irrelevant to the danger (if there even is a danger), but the aim was to communicate dread at all of the tiny shards of toxicity loosed upon our water-gulping bodies. It's like pretending it is actually informative about our colorectal risk from eating beef to reveal we are consuming more than 30,000 grams of beef a year vs. the equivalent 66 pounds. The number of discrete units on any arbitrary scale is not what's important for our health risk; it's the total weight.
To be clear, the PNAS paper didn't just convert microplastic units to nanoplastic units. The techniques did allow for the detection of a greater amount of plastic in the water, but the implications of that were played up in the media in the most dire way possible. The Washington Post headline referenced "100 to 1000 times more plastics." The subhead of that article proclaims: "A new study finds that 'nanoplastics' are even more common than microplastics in bottled water." In that article we are told, "People are swallowing hundreds of thousands of microscopic pieces of plastic each time they drink a liter of bottled water, scientists have shown—a revelation that could have profound implications for human health."
Emphasis on "could." There are no good studies on what the effects of these particles are. Most of the media outlets that covered the nanoplastic discovery disclose that there's never been a documented effect on health from the particles, but they still can't resist framing the discovery with maximum alarm.
Every person breathes, and has breathed in since the dawn of time, nanoparticles. They are in decomposing skin, leaves, and ash. Plastic is different, to be sure, which is what the current studies are properly concerned with. We do know that bottled water contains small bits of plastic, the oceans contain small bits of plastic, and our tap water contains small bits of plastic.
What we don't know is how any of this plastic may, or may not, affect us. The panic thrust upon us by almost all the media framing is premature and in many cases antithetical to the actual processes of scientific inquiry. A headline such as Earth.com's "Over 240,000 cancer-causing nanoplastics found in bottled water" is not just quantitatively illegible, it's an assertion not based on any proof of carcinogenic effect. Likewise, a recent article in The New Yorker titled "How Plastics Are Poisoning Us" is interesting, taught me things I didn't know about small plastics and "nurdles," and excited my interest in further research, but what it didn't do was present any proof that plastics are poisoning us.
The scientists behind the study themselves said they've personally reduced the amount of water they drank out of bottles. Columbia's Wei Min claimed he cut his bottled water consumption in half.
In half? I doubt lung cancer researchers cut their smoking in half. Did Herbert Needleman, the researcher who proved the effects of lead on child development, react by painting his son's nursery walls with only one coat of lead paint instead of two? The nanoplastic chemists are showing proper caution, but their continued use of some level of bottled water rebuts the more fearmongering claims attached to their work.
One example of proper perspective appeared in an Associated Press article quoting Denise Hardesty, an Australian government oceanographer who studies plastic waste. She pointed out that the total weight of nanoplastics found in a bottle of water was the "equivalent to the weight of a single penny in the volume of two Olympic-sized swimming pools."
I once swallowed a penny. I lived. We all have swallowed lots of water—bottled, tap, and maybe even from swimming pools. All of this water will have infinitesimally small pieces of plastic in it which science is now able to detect and count. The numbers associated with these tiny bits of plastic will be quite large. The conclusions we should draw from the huge counts are not quite nil, but are many orders of magnitudes less significant than the media panic over nanoplastics we're swimming in.
Editor's Note: As of February 29, 2024, commenting privileges on reason.com posts are limited to Reason Plus subscribers. Past commenters are grandfathered in for a temporary period. Subscribe here to preserve your ability to comment. Your Reason Plus subscription also gives you an ad-free version of reason.com, along with full access to the digital edition and archives of Reason magazine. We request that comments be civil and on-topic. We do not moderate or assume any responsibility for comments, which are owned by the readers who post them. Comments do not represent the views of reason.com or Reason Foundation. We reserve the right to delete any comment and ban commenters for any reason at any time. Comments may only be edited within 5 minutes of posting. Report abuses.
Please
to post comments
Nanoplastics "equivalent to the weight of a single penny in the volume of two Olympic-sized swimming pools."
Mammoplastics in breast implants, in vast volumes, are OK though... MORE than OK, especially in Spermy Daniels! 'Cause shit gives Dear Leader a raging hard-on!!! (Mentally if not physically any more, in His old age.)
This is how The Science! (tm) crowd get started. One article like this that is uncontroversial and yet shocking to our sensibilities. And then hung off of it is all the pseudo-science and crypto-religious nonsense that really damages our lives.
A family friend was lecturing me the other day about plastics causing every malady under the sun- from cancer to early puberty in girls. And this study was the start. It gives folks like him the ability to declare The Science! ™ and get everyone nodding. Then they start bringing up all these tangential studies that are either garbage, disproven, or wildly mischaracterized. And if you show the slightest pause in accepting their doom and gloom, why you are obviously a heretic.
All of this water will have infinitesimally small pieces of plastic in it which science is now able to detect and count.
They do this with chemicals too. The Daily Mail usually has some article about chemicals in the environment with scary revelations like "53,000 nanograms were detected! We're all gonna die!" They neglect to mention that that equals 0.000053 grams.
There are some substances that would be fatal if that amount ended up in your bloodstream, so it is not logical to simply dismiss small numbers out of hand just because they are small. Alexander Litvinenko died from Polonium-210 poisoning from what was estimated to be 10 micrograms. (0.00001 g) Which is over a hundred times the estimated lethal dose.
I'm talking about chemicals that might be harmful in greater amounts and you're talking about a radioactive isotope of a heavy metal. Talk about moving the goalposts.
The Daily Mail usually has some article about chemicals in the environment with scary revelations like “53,000 nanograms were detected! We’re all gonna die!” They neglect to mention that that equals 0.000053 grams.
How did I move the goalposts? I was only pointing out that you were criticizing The Daily Mail for "usually" having "some article" that mentions "53,000 nanograms" being detected as if that is dangerous when it is equal to "0.000053 grams." You were not quoting an actual article, for one thing. Instead, you made up an example of what you sort of remember seeing "usually". You didn't say anything about what the substance was, so 0.000053 grams might be dangerous or it might be a trivially small amount.
How did you move the goalposts?
Let me help--
The Daily Mail usually has some article about chemicals in the environment with scary revelations like “53,000 nanograms were detected! We’re all gonna die!” They neglect to mention that that equals 0.000053 grams.The Daily Mail usually has some article about chemicals in the environment with scary revelations like “53,000 nanograms were detected! We’re all gonna die!” They neglect to mention that that equals 0.000053 grams..
'In the environment'.
Polonium is not something one would encounter 'in the environment'. It is an extremely rare element manufactured in Russia.
Polonium -210 even more so.
That is how you moved the goalposts.
Dumb and wrong. I work with Po-210 for my work to reduce static electricity. It's more common than you think. Anyone could drop a strip outside and suddenly it's "in the environment".
‘In the environment’.
Yes, sarcasmic did say that in his comment. But it wouldn't make sense for an article to say that 53,000 ng were found "in the environment." If the journalist writing the article was fairly ignorant of basic chemistry, they might say that. But that wasn't a quote from an actual article, as I pointed out before. A technical report about a toxin found in testing environmental samples would give either a concentration or at least the amount found and how big the sample was, so that concentration could be understood.
And to repeat myself, my criticism was over the implication that it is the simple fact of an amount (or concentration) of a potential harmful substance being small that is enough to dismiss it as a concern. That is clearly not true for all substances.
There are indeed. But if the plastics were toxic at such low levels, we would have clearly seen many symptoms already from the far higher concentrations that we take for granted.
There is acute toxicity (symptoms appear shortly after exposure) or there could be long-term health risks, where you might never pin down a causal effect, but have a strong correlation that should make you wary.
https://www.nejm.org/doi/full/10.1056/NEJMoa2309822?logout=true
Given the length of time we've been manufacturing and using plastics literally in the area of food and drink storage and preparation, we would have a negative association with a longitudinal study by now if there were any negative outcomes.
This isn't some rare element being used as a poison it's a thing people interact with thousands of times a week, at least.
Maybe there is a number of microplastics that could kill a person, in fact it's very likely since a large amount of anything is likely to result in death. The number that would take might even be good to know, but so far no linkage has been found at all and frankly there is little reason to think there is one in the first place.
Also, as far as I'm aware, no one knows what the lethal dose of microplastic is but it's probably akin to outright eating a pile of plastic...which notably if you eat a pile of rocks you'll also probably die but somehow that doesn't result in any fear mongering over the mineral content of their drinking water.
Given the length of time we’ve been manufacturing and using plastics literally in the area of food and drink storage and preparation, we would have a negative association with a longitudinal study by now if there were any negative outcomes.
The fact that plastics are so pervasive might make it difficult to find any negative associations, if they are not particularly large effects. There wouldn't be an easy way to compare populations of people exposed to them to populations that were not.
The question isn't "what is a lethal dose of microplastics?" The question is "what significant harmful effects are occurring due to our level of exposure to microplastics?" We should want to know the answer to that no matter what government policies we would or wouldn't consider in response to that information.
^ This is the slimy pile of lefty shit who supports murder by cops:
JasonT20
February.6.2022 at 6:02 pm
“How many officers were there to stop Ashlee Babbitt and the dozens of people behind her from getting into the legislative chamber to do who knows what?...”
She deserved it.
The difference is there's clear evidence that polonium is dangerous even in microscopically tiny doses. For many of the substances the panic-paddlers shout about, there's no evidence that they're dangerous in micro-doses or sometimes at all.
OK. I'll switch to beer. Better safe than sorry.
Aluminum cans are lined with plastic. Better drink from glass bottles.
Cans are lined with plastic, here is a video of can being dissolved in acid. Worth a watch if you have never seen it. https://www.youtube.com/watch?v=7r7_SFdSdE4
You could have mentioned that 100 nm is smaller than any bacterium and even some viruses. They are talking about particles that could be physically moved around by bacteria.
But thank you for saying this obvious point. There has never been a demonstration of harm from microplastics. If anything, the fact that they exist for so long shows that they don't break down or react with anything. So, it shouldn't be any different than sand.
If anything, the fact that they exist for so long shows that they don’t break down or react with anything. So, it shouldn’t be any different than sand.
No, it shows that they don't break down quickly or react quickly with substances in the environment. Where "quickly" is relative to substances that are broken down to simple components in the environment over the course of days, months, or years. Substances that might take decades or centuries or more to biodegrade, like plastics, can still result in biochemical reactions that might have harmful effects to the food webs of ecosystems. (And that includes us.) Until we know with some degree of certainty, it is worth paying attention to the research and not making any assumptions in any direction.
Might, maybe, could possibly.
He's got me convinced. It's back to the Stone Age. It's the only way to be sure.
It’s back to the Stone Age. It’s the only way to be sure.
No. The only way to be sure is to nuke the entire site from orbit.
^ This is the steaming pile of lefty shit who supports murder of the unarmed:
JasonT20
February.6.2022 at 6:02 pm
“How many officers were there to stop Ashlee Babbitt and the dozens of people behind her from getting into the legislative chamber to do who knows what?…”
You’re repetative. Also, she totally deserved it you lonely fuck.
"It’s back to the Stone Age. "
They stone bottles in the stone age. You wouldn't last a minute.
Substances that might take decades or centuries or more to biodegrade, like plastics, can still result in biochemical reactions that might have harmful effects
No, they can't. Taking centuries to degrade is them exactly not resulting in biochemical reactions of any kind. That's why they don't degrade. That's why we use them so extensively for food storage and medical equipment.
Yeah, plus with plastics the most notable way for them to break down is UV which isn't found in abundance inside one's body.
^ This is the lefty shitbag who supports murder of the unarmed:
JasonT20
February.6.2022 at 6:02 pm
“How many officers were there to stop Ashlee Babbitt and the dozens of people behind her from getting into the legislative chamber to do who knows what?...”
What we don't know is how any of this plastic may, or may not, affect us. The panic thrust upon us by almost all the media framing is premature and in many cases antithetical to the actual processes of scientific inquiry.
Well, what do we know about how human health has changed over the last several decades, since plastics became common? This isn't a rhetorical question, I don't really know the answer to that. I see the occasional article that suggests that we might be experiencing higher rates of endocrine disruption, certain types of cancer, or so on, but nothing rigorous.
Finding out that there are substances in the environment and that we breathe or ingest that didn't exist centuries ago is always something to investigate and be concerned about. Panic and scaremongering? Of course not. But the article here goes a little too far in the other direction, implying that we don't even need to think about it until it is proven to be a problem. If we've learned anything about our advances in technology and out environment over the last hundred years, it is that we should not assume that something is safe because we haven't found evidence yet that it is harmful.
The precautionary principle demands that one prove a negative, which is impossible.
I don't see where I advocated for any regulation or restrictions of the use of plastics based on micro- or nanoplastic concerns. From what I can tell, when free marketers bring up the precautionary principle in a derogatory way, they mean a strong version of it that says that we shouldn't do something if there is even a small possibility of harm when we don't have sufficient evidence to do a rigorous cost/benefit analysis. I wouldn't agree with that either.
But I also don't agree with placing all of the burden of proof on showing that something will cause harm if not restricted or regulated. And that is because we have seen too many times in human history that people have moved forward with something that degraded their environment only to discover later just how much they had screwed themselves and future generations. I don't think I should even have to look up the times when people had good reason to believe that their actions would cause harm, but they did something anyway because they would make money off of it.
The point is aim skepticism equally at all claims of truth. "Making and using this substance will not cause harm," needs just as much evidence to establish it as being true as, "Making and using this substance will cause harm."
You say that proving a negative is impossible, but science is not formal logic. Science is inductive. Both of those claims would accumulate evidence showing which is most likely to be correct by doing the same experiments and using the same data to make judgements. Even before doing any experiments using the new substance, there would be data from experiments using similar substances that would allow one to make judgements on the plausibility for each claim. Maybe micro and nano plastics will turn out to be harmless, maybe not. But what we do know about these compounds and how they react with biomolecules gives us a starting point for evaluating the risks. We don't start with zero knowledge of what could happen, nor do we need to wait for absolute certainty before acting. Absolute certainty in science is what is impossible, so we always need to act to limit harm to ecosystems and thus human health without that certainty.
Well, what do we know about how human health has changed over the last several decades, since plastics became common?
That people live a lot longer and we can cure a lot more diseases?
But the article here goes a little too far in the other direction, implying that we don’t even need to think about it until it is proven to be a problem.
No - the article says there's no cause for panic. It's right in the headline.
^ This is the slimy pile of lefty shit who is fine with murder of the unarmed:
JasonT20
February.6.2022 at 6:02 pm
“How many officers were there to stop Ashlee Babbitt and the dozens of people behind her from getting into the legislative chamber to do who knows what?...”
Still quite proud of it, too. I would have changed my label if I had advocated for such.
"I would have changed my label if I had advocated for such."
You merely pay the salaries of the thugs. Hence no shame, no remorse, no change of label.
Fuck off and die, asshole.
Without giving away any spoilers, can anyone answer if it's OK if I skip The End Of Doom II: Hell on Earth and go straight to The End Of Doom III and The End Of Doom Eternal or will the story not make sense if I do that?
Both parties will tell you throwing money at a problem will always solves the problem.
Just look at the War on Poverty and the billions of dollars spent on it...and voila! There's no more poverty in America today.
Money? I think you're confused about what they want.
They're clearly angling to criminalize some type of behavior. Creating an anti plastics industrial complex is just a happy coincidence.
Well, there's almost certainly going to have to be some sort of plastic remediation done, like Superfund sites. So someone on the right team will be making bank on "solving the problem".
Well, there’s almost certainly going to have to be some sort of plastic remediation done, like Superfund sites.
Why?
Better question, how the fuck is that at all a realistic idea when we're talking nano sized pieces that cover the entire surface of the Earth.
That is quite probably impossible, akin to removing radiation residue that spread after the first atom bomb detonation.
Given the quotes around "solving the problem", I'm inclined to think your need to calibrate your sarc-o-meter.
It’s always fun when strong property rights advocates tell me it’s ok for someone to pollute my water or my air. It’s much more convenient to maintain that the commons belong to no one than to acknowledge that they belong to everyone.
There is no universe where plastic belongs in drinking water.
I especially like the part about nickels. Some of these plastics have a serum half life of 10 years, but go ahead and act like the norm is for someone to drink a single bottle of water every decade or so if it proves your point. Whatever that point is.
Also feel free to leave out the part about these nanoparticles crossing the blood-brain barrier, passing through cell walls, and exhibiting estrogen like properties (which can't possibly have anything to do with plunging testosterone levels). Whatever serves to convince people that their property rights aren't really being violated here.
Nano plastics were just discovered dingleberry. None of what you said is true. You're conflating studies about specifics plastics to micro plastics to newly discovered nano plastics.
I'll keep in mind that the same people touting these studies were the same type of people that originally brought us anti vax autism hysteria. We know the value of science to them.
You’re conflating studies about specifics plastics to micro plastics to newly discovered nano plastics.
It's all the things. If 100nm-sized non-biological particles are permeating your blood-brain barrier and cell membranes, that's a problem with your blood-brain barrier and cell membranes, not the particles. If you've got microplastic particles that have been swimming around in your bloodstream for 10+ yrs., that's a problem with your heart, kidneys, and liver, not the microplastics.
The estrogenic effects of plastics is nothing compared to the estrogenic effects of plastic byproducts which themselves are generally orders of magnitude weaker than the actual estrogen hormones we dump/leach/bleed/seep/trickle into our water and food supplies from natural sources that actually are the right size and chemical makeup to permeate cell walls and capillaries.
It’s always fun when strong property rights advocates tell me it’s ok for someone to pollute my water or my air. It’s much more convenient to maintain that the commons belong to no one than to acknowledge that they belong to everyone.
So then *you're* the one who got nanoparticles in *our* air and water and it's *you* whom we should murder to resolve the issue of plastic nanoparticles in *our* water!
So distill all your water. Why is it my problem to deal with your paranoia?
I'm not sure how belonging to everyone differs from belonging to no one.
And I'm pretty sure you contribute as much to plastic pollution as most people do. And also reap the tremendous benefits of plastics as everyone does.
We used to play with Mercury in 4th Grade Science Class. Now where I work calls a HAZMAT if somebody breaks a fluorescent light bulb.
According to mattwa, it’s because we’ve all turned into pussies because plastics cause lower testosterone.
Speak for yourself. I don't drink bottled water 🙂
So then you're complaining that all the nanoplastics are making your blood-brain barrier hurt because you're just a whiny bitch?
This kinda reminds me of the "meat hysteria" from when I was a kid, where the anti-meat crowd was screaming that it takes 'so much time' for meat to digest, implying it sits in the gut for that a mount of time.
No, it doesn't. Meat either gets digested or it "moves" along to exit the body. "I'll see you again" in a few hours.
As with the swallowed penny, I'm pretty sure our "movements" are filled with those plastics...and other things our bodies simply can't use.
From the wikipedia page on anogenital difference:
Early studies showed that the human perineum was half as long in females as in males, but it has since been found to be three quarters the male distance in females,[6] although males have more variance. Measuring the anogenital distance in neonatal humans has been suggested as a noninvasive method to determine male feminisation and female virilization and thereby predict neonatal and adult reproductive disorders.[7]
A study by Swan et al. determined that the AGD is linked to fertility in males, and penis size.[3] Males with a short AGD (lower than the median around 52 mm (2 in)) have seven times the chance of being sub-fertile as those with a longer AGD. It is linked to both semen volume and sperm count.[8] A lower than median AGD also increases the likelihood of undescended testes, and lowered sperm counts and testicular tumors in adulthood. Babies with high total exposure to phthalates were ninety times more likely to have a short AGD, despite not every type of the nine phthalates tested being correlated with shorter AGD.[3]
Swan et al. report that the levels of phthalates associated with significant AGD reductions are found in approximately one-quarter of Americans tested by the Centers for Disease Control and Prevention (CDC) for phthalate body burdens.[3]
Women who had high levels of phthalates in their urine during pregnancy gave birth to sons who were ten times more likely to have shorter than expected AGDs.[9]
A 2018 study by Barrett et al. found that infant girls born to women with polycystic ovary syndrome (PCOS) had longer AGD, suggesting higher fetal testosterone exposure, than girls born to women without PCOS.[10]
The above mentions phthalates. They are chemicals in some plastics. They are also in microplastics and nanoplastics. They are called endocrine disruptors and have similar effects to estrogen, the female hormone, on fetal development. Apparently, a fetus doesn't need to drink water from a plastic bottle to show phthalate contamination, as it comes directly from the mother's blood stream.
From history:
mtrueman|8.30.17 @ 1:42PM|#
"Spouting nonsense is an end in itself."
I'm all for questioning and being skeptical of the health nuts out there saying things like these plastics are going to kill you.
But they will ask things like, Well, what explains the rapidly increasing rates of cancer and many other things in modern times? And obviously there are various rejoinders. But they also make the argument of erring on the side of caution when it comes to your health.
Even with all of our gee-whiz science and technology, like this ability to detect nano-particles, conclusively establishing causative relationships between deadly health problems and anything remains rather difficult and elusive. Unfortunately this simple fact takes a lot of the bite out of the basic sort of smug skeptic position here of "Well there's no proof that it harms you."
“Well there’s no proof that it harms you.”
There's pretty strong evidence that the chemicals within some of these particles of plastic are harmful to the normal development of animals.
"The smallest-sized particles the researchers picked up measured 100 nanometers. This means we can now detect bits of plastic so small that 10 million of them would amount to a piece of microplastic a fraction of the width of a hair."
I'm not sure what you're trying to say, but 100 nanometers times 10 million is a meter! I think you lost some orders of magnitude there...
"I’m not sure what you’re trying to say, but 100 nanometers times 10 million is a meter! "
Only if you line them up end to end.
So, where does the 10 million number come from?
I wouldn't take any of this drivel too seriously. I was just amused at the image of someone lining up 10 million pieces of tiny plastic end to end.
To be clear, it's almost certainly some sort of typo.
That said, Raman spectroscopy (invoking metaphor to avoid too much science) works by detecting how long spaghetti noodles are, not how wide. Below 100nm, in length, the spaghetti noodles can't be differentiated from macaroni, penne, or fusilli noodles. In width, *none* of the spaghetti can be differentiated from virtually any other noodle.
If you took all the "spaghetti noodles" out and laid them together width-wise (which they may or may not naturally do), 10 million of them (0.1 nm) come out to roughly 10X (1 mm) the width of a human hair (100 um).
The smallest-sized particles the researchers picked up measured 100 nanometers.
It should be noted for clarity that, for lots and lots of polymers, this dimension/scale constitutes single molecules.
That is, the assertion that they cause cancer isn't just unfounded, it's plainly wrong as normal cells grow and mature in direct contact with doses of these compounds orders of magnitude upon orders of magnitude larger. Cancer fighting drugs that kill naturally-occurring sources of cancer within our own, each and every, human body are produced and delivered overwhelmingly successfully all the time.
This isn't even remotely science. It's homeopathy as assumed fact.
It's Sciencism.
You're off track here. It's not the size of the particles that's the problem. It's the chemical in the particles. Phthalates, for example, have long been identified as an endocrine disruptor, linked to all sorts of difficulties with animal (yes, that includes human) reproductive development.
Right. As I indicated above. If the plastics themselves were toxic, nobody would use them for holding culture media or growing cells or anything else because it would poison the hell out of anything it came into contact with. There is the case that plastics could be contaminated with mold-release agents (to get them off the machinery), plasticizers (to make them more flexible or impart other physical characteristics), or breakdown products from the result of exposure but, for 100 nm particles, you’re talking about single molecules (and still/again, if the plasticizers or mold release agents were carcinogenic the people knife, spoon, and sporking them directly into their mouths and washing it all down with a pull from the straw in their big gulp would be croaking at a rate phenomenally higher than the people diluting them out over the several hundred, if not thousand, reuses of their water bottle.
It’s very much akin to the bullshit people were spouting (and publishing) about 100s infectious units of COVID in a microfomite that could or couldn’t penetrate a mask (which couldn’t be true unless the IUs and the size of COVID were way off or masks didn’t work/leaked) while epidemiological data showed that same age peers could spend the entire duration of a COVID infection in the same bubble, if not face-to-face presence (no mask) of someone with COVID and only have an ~50% chance of infection and for younger peers, have a near non-existent chance.
It’s a dishonest, sophist-but-unsophisticated invocation of homeopath and the most trivial of Zeno’s Paradoxes.
Reduce your bottle water consumption? Why not eliminate it? There's no benefit to the stuff unless your local tap water is badly contaminated and all those bottles are one of the sources of the micro-plastics you're worried about.