Plastics, let alone microplastics, are a rather small problem that seem to get a lot of airspace.
There are no established health effects of microplastics. There are magnitudes worse health problems in e.g. both under and overnutrition that cause a lot less panic and fuss.
> There are no established health effects of microplastics.
It'd be more true to say, "There are no established significant health effects of microplastics on humans." FWIW, the article you linked to doesn't say "no effects", but "limited evidence for significant adverse health impacts".
When reading research papers, ‘significant’ is usually meant to mean ‘statistically correlated’ which varies from our typical lay definition of ‘very impactful’, which would be described using the term ‘effect size’
Micro plastics is like CO2. Spread out everywhere, can't be sequestered or reversed.
Rather than saying it's not a problem now — it's worth saying what's the threshold beyond which health complications begin (that number can't be infinity), and based on current growth levels how far we're off from it. If that's like at current rate of growth we still have 5000 years, then yeah I would agree with you and ignore the news. But just saying retrogressively that there is no conclusive evidence based on what we're eating so far – unfortunately sounds only politically correct, without considering the spirit of doing science (exploring the horizons / where the limits are).
A lot of issues like you mention can be a big problem on the population level, but not in an individual level if you're conscious of what you eat. This doesn't seem to be the case with microplastics, they seem to be in everything.
You might call it panic to minimize it, and you'd be right to do so if we here were in charge of nutrition for a population; but I'm guessing most of us are in charge of our own nutrition and maybe a family's, so the information to deal with that is pretty valuable.
Can someone ELI5 this for me: how would microplastics passing through a digestive system end up in "proteins*"? Are they being stored directly in the fats, within cells, between muscle fibers...?
(* the article seems to be using the term "protein" in the culinary sense, not the molecular sense).
You know how mercury bioaccumulates up the food chain? It looks like microplastics are similar [1] [2], and they are everywhere in the food web [3]. It's even in the bottled water [4].
(edit: yes, yes, no surprise it's in the bottled water, maybe we shouldn't be selling bottled water if it's full of microplastics? Less bottled water, more water dispensers everywhere)
There was another posting within the last few months that showed the particular microplastic they studied fit into the same ‘lock’ per lock/key of a biological molecule interaction and prevented the desired molecules from working together. It could be that or a different mechanism.
https://news.ycombinator.com/item?id=38322944
The article only reports number of microplastics without reporting mass. This is particularly difficult to interpret when fibers are responsible for so much of the total:
Notably, across all samples, nearly half (44%) of the identified microplastics were fibers, which is consistent with other studies suggesting that fibers are the most prevalent form of microplastic in the environment.
Are 4 fibers of 50 micron length 4 times more dangerous than one 200 micron long fiber? There's no discussion of it in the article, but reporting microplastics by number of countable particles carries that implication.
I wonder how much of this stuff we inhale from our dryer exhaust when washing outdoor/athletic wear? I used the lint from my dryer as a fire-starter once and it definitely smelled like burning plastic.
Stop driving? Most microplastic in water come from tires.
I've been trying to make small moves away from car infrastructure in my town and the response is, well, less than positive.
We already tacitly accept that cars are one of the biggest causes of death. Reducing car infrastructure to reduce microplastics, where we don't even really know the harm, seems far far more challenging.
And also synthetic clothes. According to the study they found more plastic fibres than plastic particles in many samples.
These get released when you launder your clothes, ending up in the drain water and ultimately the ocean.
Solution? Buy clothes with natural fibres (cotton, wool, etc) instead of plastics. And wash your clothes in a modern washing machine with a microfibre filter on its drain outlet.
Assuming you dump the sludge in the bin when you clean the filter then it’s much better than going into the ocean.
Depending on your location, they’ll either get destroyed by incineration or put in landfill where they’ll do less harm and hopefully break down after a few centuries.
Of course, if you clean the filter by flushing the sludge down the sink then you didn’t solve anything.
The risk is runoff into the ocean or insertion into the water table through seepage within the dump into the soil. Furthermore incineration doesn't atomize these plastics; the smoke plumage may become a part of rain clouds which either recirculates the contaminants into the water cycle, and thus either in the local environment or into the ocean, again.
Obviously these are geography-relative concerns. But they aren't rare.
> About 34% of the emitted coarse TWPs (tire wear particles) and 30% of the emitted coarse BWPs (brake wear particles) (100 kt yr−1 and 40 kt yr−1 respectively) were deposited in the World Ocean. These amounts are of similar magnitude as the total estimated direct and riverine transport of TWPs and fibres to the ocean (64 kt yr−1).
Water pollution from brake and tire dust, (and oil drippings,) is well proven. If you build infrastructure to handle runoff from roads, you need to mitigate pollution in that runoff too.
> Most microplastic in water comes from washing machines. Synthetic fibers from clothes.
I know less about that but from what I've skimmed it appears to be true too.
What town is that? It seems like the success of diversifying away from cars depends on the place and how it grew. LA, for example, grew at the time of peak automobile infrastructure investment and it's basically unrecoverable at this point. There are probably other reasons why places like LA are so locked in to cars now, but that's the one that seems obvious to me.
It's a town with one of the highest percentages of bike commuters in the state, actually.
However there's also a regressive aspect that refuses to make any accommodations for anything except cars, and these people have veto power over non-car infrastructure. There is no built-in veto power for new car infrastructure, and in fact existing law requires car infrastructure as a base for any sort of building, for example parking minimums.
Most of the city was built 1960-1980, so based on car designs. But it's small enough that small amounts of change would eliminate car dependence.
>Tire factories start with bulk raw materials such as synthetic rubber (60% -70% of total rubber in the tire industry[2][3]), carbon black, and chemicals and produce numerous specialized components that are assembled and cured.
Looks like most of the rubber used these days is synthetic[1], usually made of styrene and butadiene which could easily degrade into base monomers or at least shorter chains.
Car and light truck tires are apparently only about 19% rubber.[1] More than half of a tire's composition is synthetic polymers, fillers, and textiles (e.g. polyester, rayon, nylon).
You say "vast" but we have to outlaw non-car options and legislate that only car options are allowed for nearly all our land.
If we were to even legalize non-car options, we might discover what the market actually wants. And the necessity of those laws kind of shows that the non-car option must be legally suppressed to prevent its true market preference from being revealed.
To everyone who thinks that the "vast majority" of people prefer driving, I say: show the confidence of your convictions and make it legal to build other options.
I hate to be the bearer of bad news, but birth rates are already pretty low, and, worse than failing to deal with the problem, some people think that is a good thing.
If you donate blood as soon as possible from your last blood donation (per federal regulations), you can remove 50% of your microplastic content per year. Some studies have also shown that going to saunas/sweat lodges also lower your microplastic content.
I don't think becoming vegetarian helps. From the article:
> The study found evidence that food processing is a likely source of microplastic contamination, as highly processed protein products (like fish sticks, chicken nuggets, tofu, and plant-based burgers, among others) contained significantly more microplastics per gram than minimally processed products (items like packaged wild Alaska pollock, raw chicken breast, and others).
If you look at the actual data, tofu had the third lowest concentration of microplastic particles per gram (0.03, vs 0.02 for pork loin chop and 0.01 for whole chicken breast).
The press release does a disservice to the study by referring to the highly processed group as a whole and not excluding tofu. For reference, the breaded shrimp and fish sticks were measured to have 1.2 and 0.26 particles per gram.
Regardless if a processed food like tofu has minimal plastic concentration, I would assume minimally processed whole plant food like beans and nuts would also have low microplastic exposure. The study found little total plastic from packaging, their evidence pointed towards the processing.
Did you account for calories? Beef has ~3-4X the calories per gram of tofu.
I would guess plants have more microplastics as they just pull things out of the soil and store them (why many plants have a ton of heavy metals). Animals at least have some systems for filtering and processing unwanted items.
The graph makes sense to me, processed (plant-based or factory-breaded) and shrimp seem to be the main ones. Buy fresh and you’ll be alright is what I read from this.
I sometimes have this feeling that in the future, when all of the science on this stuff is well established, our future enlightened society will simply take the view that plastic is poisonous. I think it'll be the same way that we think of lead, mercury, etc: like "wash your hands if you touch the stuff" levels of poisonous. I would not be surprised if society makes this shift in the next 20-30 years. Some of the recent results are really nuts:
It goes on and on. There are studies showing it gets into the placenta, harms animals, affects behavior, stays in your system forever, bioaccumulates all the way up the food chain and makes its way into every organ, and so on. This is all within the last few years. It seems like bottled water is a vector for this stuff very similar to lead pipes, and tires are a vector similar to leaded gasoline, and that the evidence is basically all there and all that is needed is a big epidemiological "smoking gun" study to put it all together.
Of course not every single thing one could possibly call "plastic" need be equally unsafe. Probably some better plastic will be devised which is safer for use in tires and etc. Still, I think there will be a society-wide push against so-called "plastic", in general. People will probably push to replace everything made of plastic with something else: replacing saran wrap with parchment paper, Tupperware with glass, etc.
I'm not super interested in defending this rigorously as it's really just a hunch, but I'm curious if this is what happens.
> I sometimes have this feeling that in the future, when all of the science on this stuff is well established, our future enlightened society will simply take the view that plastic is poisonous. I think it'll be the same way that we think of lead, mercury, etc
I don't.
The effects of lead or mercury poisoning are fast-acting and obvious. All the links you provided talk about the release of plastics into the world, but the details on how that affects things are sketchier than say , mercury poisoning , because the symptoms are slowly accruing and ambiguous compared to lots of other environmental contaminants.
>Notably, across all samples, nearly half (44%) of the identified microplastics were fibers, which is consistent with other studies suggesting that fibers are the most prevalent form of microplastic in the environment.
Seems like one could live on a vegan diet and still be consuming a lot of plastic fiber. My favorite blankets, rugs, and t-shirts are all 100% polyester.
Even if I managed to use avoid plastics at home, plastic lint is everywhere in public too.
An even stranger but annoying problem is even if you buy 100% cotton, the stitching is usually a polyester. It is difficult to buy cotton threads for home sewing
Avoiding synthetics in clothing is indeed difficult. I buy 100% natural fibers where I can, but sadly often the best one can do is ~90% natural ~10% synthetic.
100% cotton would seem to be widely available? Certainly for shirts, t-shirts, jumpers, trousers, socks. I don't wear anything other than cotton really for those items.
For some reason they have started putting stretchy stuff into cotton jeans - maybe style, or maybe (my pet theory) that good quality cotton is no longer economic for jean production, and so they have to use rougher cotton, which needs the stretchy stuff to be comfortable enough to wear.
I think the jeans thing is just because most people want their jeans to feel and stretch like yoga pants and not jeans. The selvedge denim cult still is usually 100% cotton, and about the same price as stretchy designer jeans, but most people don’t want this.
We are burning huge amounts of fossil fuels to run the economy. This economic boon leads to longer lifetimes, at a huge but externalized and delayed cost.
> it seems like most people are doing... just fine?
Where do you live?
Outside of affluent areas, I think most people these days would laugh at such an absurd claim. We are not fine, physically or mentally.
Our soil isn't fine. Our air isn't fine. Our water isn't fine - not our wells, our rivers, our lakes, our oceans, or even our icecaps. Our species are being made extinct at 1000x the background rate of extinction. Anyone fine with this is on the ignorant side of blissful.
Are you claiming that declining fertility is due to plastic, rather than to increasing wealth, education of women, and access to contraception? If so, then I'm going to have to ask you for a) a source and b) a plausible mechanism.
There's very strong evidence that both sperm counts and testosterone levels are going down (wikipedia it) worldwide over the last 60 years.
The mechanism here would be that many plastics are or contain endocrine disruptors. Or just an unknown mechanism (there's just so much about biology we don't know).
I believe there's also evidence that younger generations are having less sex. There's also a claim that people have much less "mature" (i.e. sexually-developed) facial features.
Of course this could all be tested by a proper study.
Now back to your point, your first reaction might be "All my friends aren't having kids because they don't want to, none are trying and can't." But if sex-drive is down across the board that may explain it. America doesn't even self-replace (unless you count new immigrants).
Instead of looking for evidence of consumption risk at current/past levels — it would be good to know: what is the threshold of continuous daily ingestion beyond which microplastics are harmful. The answer can't be infinity of course, so it would be worth finding the threshold, and then how far we're off from that threshold based on current growth.
Not suggesting to have humans consume concentrated concoctions of plastics, but however ethically science allows.
On one hand, plastic reduces weight, transportation costs and the costs of things and is more versatile. On the other hand it causes another form of pollution. Modern life would be very different without plastic.
Plastic gets consumed by oceanic microorganisms, though slowly. Take a look at the fascinating microscopic images of plastic partially eaten by microorganisms in this 2013 research article, "Life in the Plastisphere: Microbial Communities on Plastic Marine Debris":
Plastics also break down to simpler hydrocarbons and carbon dioxide with prolonged exposure to sunlight. Unfortunately, these gaseous small molecules are greenhouse gases, but they don't persist for as long.
"Production of methane and ethylene from plastic in the environment"
People tend to care disproportionately about human life. We don’t actually know whether we’ll adapt at the pace required to overcome widespread plastic contamination (or really whether we even need to adapt).
I think the idea we have this highly dense energy source pervasively available across the earth in all biomes with an exposed surface area that is unfathomable, life will adapt to consume that source of carbon rich energy. I suspect we may be bringing the end of the age of plastics rapidly.
And the lifecycle of the likely consumers of this energy source have much faster reproduction cycles, therefore faster ability to evolve to use this energy source.
I'm very curious how we will protect against this, otherwise bacteria will eat away at our car dashboards and such.
Have we been able to link any real harm to microplastics? I know it sounds bad intuitively. But can we draw a link to any diseases? What if this just amounts to fear mongering?
No but that's a silly standard. I can't go back in time and blood test my infant self. We have microplastics everywhere because of their widespread use. That's been occurring for a few generations now. There is no rational reason to think that we only accumulated them when we first noticed them. No the rational explanation is its been that way as long as we've been mass exposing ourselves to plastics which is right around the end of the second world war. And if car tires are as big of a contributor as some studies indicate then its been even longer because vulcanized rubber is a prewar invention.
Then there is nothing to worry about because everything since WW2 has been fine as far as cognition and general health is concerned. Although, IQs and sperm quality have been declining for a while now but it's probably unrelated to all the plastic pollution.
I think there likely is little cause for concern. Is it contributing to poor health? Maybe but if it is then its a small contribution. There are much bigger issues like poor diet and lifestyle. HFCS for example was easy to link to poor health and it should probably be outlawed.
It's a good thing most foods now have sugar substitutes like splenda and you can request sugar substitutes in your coffee as well. HFCS is a non-issue.
I have done zero research, am not at all qualified to say any such things… but I feel like microplastics will eventually be looked back on the way we look back on asbestos today. “People used to throw PLASTIC in the ocean?!” We are in that awkward period of being aware, yet the damage has been done, so now we wait for the long-term effects to manifest.
Again, probably wrong, not at all an opinion to be taken as fact, just a gut feeling. History tells us that there will at least be SOMETHING perceived as normal today that is later discovered to be not okay, anyway. Plastic, social media, hell, maybe even EV after 50 years of batteries rotting in landfills.
And if the exposure is as universal as it sounds, then we can place some upper bounds on the amount of harm. With asbestos, the exposure was somewhat limited, but had greater consewuences. With plastics, we are all getting it.
What upper bounds? One of the higher-confidence hypotheses of the effects of plastic contamination is reproductive disruption. Since these plastics bioaccumulate and pass from mother to child, there’s reason to worry about intergenerational accrual of reproductive damage.
So as far as I can tell, the “upper bound” of harm is reproductive collapse of our species?
>What upper bounds?
Well we know it isn't acutely toxic because people aren't just dropping dead inexplicably. And we know it isn't drastically raising cancer rates because, again those haven't inexplicably shot up.
Another pretty decent hypothesis of plastic contamination's effects is obesity (it's been seen both in vitro and in non-human animals). People absolutely are dropping dead en masse of obesity and related complications, and while obesity is proximally explainable (calories), the explanation of why people are consuming so many more calories is contested, at best.
So I don't think we know enough to say confidently that people aren't just dropping dead inexplicably.
IIRC there is some evidence of hormonal changes related to some volatiles associated with certain types of plastics. That might have something to do with it. But Obesity can also easily be explained by more mundane things like terrible diet and lifestyle and there's a huge body of evidence to show that if you change those, you lose weight.
>So I don't think we know enough to say confidently that people aren't just dropping dead inexplicably.
Well proving a negative is impossible. Further research into the potential health effects is needed. But at this stage I think worrying over every report that we found plastic in more and more places isn't cause for alarm until we actually know its dangerous.
1) In-vitro and animal model data showing metabolic and reproductive harm from plastic contamination
2) Plastics continuing to be found contaminating more and more things that humans interact with or ingest
3) Strong evidence that this contamination bioaccumulates within individuals
4) Strong evidence that this contamination accumulates across generations
5) Strong evidence that this contamination is approximately impossible to remove from water and soil
6) Strong evidence of very similar metabolic and reproductive harms that have been found in-vitro and in animal models showing up across extremely broad swaths of the human species.
I would buy into the, "no alarm until we know it's dangerous" approach if there were a way to undo the harm after the fact, or if there were a way to quickly "know it's dangerous," or if this contamination wasn't covering pretty much the entire globe, but none of those things is true.
We have no method to ascertain population-scale danger prior to that danger being pretty much irreversibly realized.
I've identified what would change my position from alarmed to not-alarmed. What, concretely, would change your position from not-alarmed to alarmed? There is no way to do a randomized controlled trial of plastic poisoning. So what would constitute "knowing" it's bad for us?
Yeah it’s wild, plastic is so ubiquitous and amazingly useful that I don’t see it ever going away.
My guess is that it is never replaced, and instead, we will pour time and money into treating whatever (if any) issues microplastic consumption cause instead. Theorizing for fun, it’s pretty bleak though hah
There are no established health effects of microplastics. There are magnitudes worse health problems in e.g. both under and overnutrition that cause a lot less panic and fuss.
https://www.undp.org/kosovo/blog/microplastics-human-health-...