6 ms·

"Microwood" is basically just cellulose, aka insoluble fiber, which naturally exists in our food. "Microsteel" is just elemental iron which is a necessary nutri

"Microwood" is basically just cellulose, aka insoluble fiber, which naturally exists in our food. "Microsteel" is just elemental iron which is a necessary nutrient. Microplastics are novel hydrocarbons that don't exist in nature. They're similar to cellulose but no organisms exist that eat them. They're believed to be nonreactive and therefore harmless but they might bioaccumulate which could be bad, or they might react with things in our bodies in unknown circumstances. We have limited experience with these molecules so it is hard to say.

Zaskoda 2y ago
Elegant and pithy answer to a well asked question.
rcMgD2BwE72F 2y ago
And plastics are full of endocrine disruptors, which are pretty bad for human health too.
- amanaplanacanal 2y ago
  My current theory is that long term plastic exposure is what is driving the obesity epidemic.
dbingham 2y ago
Missing from this answer is the early evidence that they may be _very_ harmful. Early evidence suggests they are not non-reactive. They disrupt many of the body's systems in ways we're only beginning to understand. > Various examples of damage caused by microplastics have been reported, such as microplastic accumulation in the bodies of marine and aquatic organisms (leading to malnutrition), inflammation, reduced fertility, and mortality. The threats that microplastics present to the human body have not yet been clearly identified. However, previous reports have shown that ultrafine microplastic absorption resulted in complex toxicity in zebrafish,2 and that microplastics under 100 nm in size can reach almost all organs after entering the human body.3 Therefore, concerns exist regarding the negative effects of continuous microplastic accumulation in the human body. https://pmc.ncbi.nlm.nih.gov/articles/PMC10151227/ https://pmc.ncbi.nlm.nih.gov/articles/PMC10151227/ > Microplastics have been found in a variety of organisms and multiple parts of the human body. We emphasize the potential impact of microplastics on the early exposure of infants and the early development of embryos. At present, the toxicity research on microplastics show that the exposure will cause intestinal injury, liver infection, flora imbalance, lipid accumulation, and then lead to metabolic disorder. In addition, the microplastic exposure increases the expression of inflammatory factors, inhibits the activity of acetylcholinesterase, reduces the quality of germ cells, and affects embryo development. At last, we speculate that the exposure of microplastics may be related to the formation of various chronic diseases. https://pubs.acs.org/doi/10.1021/envhealth.3c00052 https://pubs.acs.org/doi/10.1021/envhealth.3c00052
- stevenAthompson 2y ago
  [flagged]
  - inglor_cz 2y ago
    But fertility dropped. May be a contributing factor.
  - hansvm 2y ago
    Or not bad enough to overcome other benefits that came out around the same time.
  - thoroughburro 2y ago
    “Accumulation” is a keyword you might want to examine.
  - littlestymaar 2y ago
    This argument makes no sense, life expectancy increased a lot after the invention of leaded gasoline†, yet nobody would say it's harmless. [†]: Works as well for high fructose corn syrup or Fentanyl.
    - stevenAthompson 2y ago
      I'm not saying it's harmless, I'm saying that even if it is harmful it's not by enough to justify the panic and sudden lifestyle changes these articles sometimes lead to. Remember the black spatulas a while back, and how it turned out to be a math error?
      - wonnage 2y ago
        Is scooping out your food out of the crappy plastic takeout container into a bowl before microwaving an example of “panic and sudden lifestyle changes”? Seems like a pretty minor change to me. I’m already going out of my way to not put metal in there anyway…
      - 2y ago
rendaw 2y ago
Can the body break down cellulose though? It can't digest it at least. And do reactions that could use naturally occurring iron compounds work with steel alloys designed to be non-reactive? I think something else that doesn't get mentioned is it's not just the risk of microplastics reacting, the physical non-reactive presence of particles can clog and get in the way of natural processes mechanically. So nonreactive shouldn't be taken to imply harmless.
- Suppafly 2y ago
  >the physical non-reactive presence of particles can clog and get in the way of natural processes mechanically Source?
  - rendaw 2y ago
    TBH I can't remember what I was looking up when I first read about that (I feel like it was metals, glass, or cellulose again), but https://www.pnas.org/doi/10.1073/pnas.2104610118 https://www.pnas.org/doi/10.1073/pnas.2104610118 seems pertinent: > In general, mechanical interactions of microparticles and nanoparticles on biological membranes are vaguely studied, despite their importance for biological systems (29, 41). Hereby, we will demonstrate that these microplastics induce a mechanical stress of model cell membrane without the need of indirect assumptions about biological pathways (26, 27).
- skirmish 2y ago
  > physical non-reactive presence of particles can clog and get in the way of natural processes mechanically That would mean fiber in food is harmful since it is not digested. Cellulose is just a common type of natural fiber. Meanwhile: USDA recommends that people consume the following amounts of fiber per day: -- Women ages 31–50: 25 grams -- Men ages 31–50: 38 grams
- atombender 2y ago
  No, it can't. Cellulose is the main type of insoluble dietary fiber, and is in leafy vegetables, beans, peas, and many other foods. It's widely accepted as being good for digestion. Too much fiber can cause constipation and gas, but most people probably don't get enough fiber, so that's rarely a problem.
sillyfluke 2y ago
The reason for "why microplastics?" is because human use of everyday objects are more plastic than wood or steel. The reason for "why teabags?" is because of previous studies and because I think tea makes it to the top five of the most ingested liquid list. I seem to recall a recent study of microplastic levels in a general population, where people with higher microplastic levels seemed to be tea drinkers, which took some by surprise at the time. I think the population under study was from latin america, if I'm not mistaken. Since this study now has flooded the search results, I'm having trouble finding that specific study. Be that as it may, it's likely that there is a focus on tea because tea-drinkers scored high on microplastics in previous studies.
- fy20 2y ago
  > The reason for "why microplastics?" is because human use of everyday objects are more plastic than wood or steel. Over the past few decades there has been a trend for plastic based materials replacing natural materials in everyday things. Polyester textiles: Found in most clothing, bedding, and furniture upholstery. Polyurethane coatings: Applied on wooden furniture to give it a glossy, durable finish. Vinyl flooring and tiles: Replacing traditional wood or ceramic options in many homes. Nylon carpets and rugs. Synthetic leather (PU or PVC): Found in everything from sofas to shoes, replacing genuine leather. It's got to a point where it's now hard to find natural materials in some categories. My wife was looking for a new sweater and most shops only had polyester or acrylic.
lkbm 2y ago
> "Microwood" is basically just cellulose, aka insoluble fiber, which naturally exists in our food. This is one thing that confused me about the first article I saw on this. The paper lists three things it detected, one being cellulose, and various articles will list them all together as if they're just three microplastics to be worried about. The paper seems to encourage this reading with this line: "the third one (from the supermarket) being cellulose (CL, sample 3), a bio-based polymer"[0]. Was sample 3 completely fine? If so, why is say "Nanoplastics were obtained from three teabag brands during a standard preparation"? Are they classing cellulose as nanoplastics? [0] https://www.sciencedirect.com/science/article/pii/S0045653524026377?via%3Dihub https://www.sciencedirect.com/science/article/pii/S004565352...
giantg2 2y ago
We know that some plastics mimic hormones (eg estrogens), which can cause problems (eg estrogenic cancers).
thayne 2y ago
> "Microsteel" is just elemental iron which is a necessary nutrient. Steel also contains carbon and if it is stainless steel it also has chromium and probably other metals.
- SoftTalker 2y ago
  The body does need trace amounts of chromium.
llm_trw 2y ago
Wasn't asbestos non reactive?
userbinator 2y ago
Microplastics are novel hydrocarbons that don't exist in nature. They are short-chain hydrocarbons, which most definitely exist in nature. https://en.wikipedia.org/wiki/Petroleum_seep https://en.wikipedia.org/wiki/Petroleum_seep

Zaskoda 2y ago

Elegant and pithy answer to a well asked question.

rcMgD2BwE72F 2y ago

And plastics are full of endocrine disruptors, which are pretty bad for human health too.

amanaplanacanal 2y ago
My current theory is that long term plastic exposure is what is driving the obesity epidemic.

dbingham 2y ago

Missing from this answer is the early evidence that they may be _very_ harmful. Early evidence suggests they are not non-reactive. They disrupt many of the body's systems in ways we're only beginning to understand. > Various examples of damage caused by microplastics have been reported, such as microplastic accumulation in the bodies of marine and aquatic organisms (leading to malnutrition), inflammation, reduced fertility, and mortality. The threats that microplastics present to the human body have not yet been clearly identified. However, previous reports have shown that ultrafine microplastic absorption resulted in complex toxicity in zebrafish,2 and that microplastics under 100 nm in size can reach almost all organs after entering the human body.3 Therefore, concerns exist regarding the negative effects of continuous microplastic accumulation in the human body. https://pmc.ncbi.nlm.nih.gov/articles/PMC10151227/ https://pmc.ncbi.nlm.nih.gov/articles/PMC10151227/ > Microplastics have been found in a variety of organisms and multiple parts of the human body. We emphasize the potential impact of microplastics on the early exposure of infants and the early development of embryos. At present, the toxicity research on microplastics show that the exposure will cause intestinal injury, liver infection, flora imbalance, lipid accumulation, and then lead to metabolic disorder. In addition, the microplastic exposure increases the expression of inflammatory factors, inhibits the activity of acetylcholinesterase, reduces the quality of germ cells, and affects embryo development. At last, we speculate that the exposure of microplastics may be related to the formation of various chronic diseases. https://pubs.acs.org/doi/10.1021/envhealth.3c00052 https://pubs.acs.org/doi/10.1021/envhealth.3c00052

stevenAthompson 2y ago
[flagged]
- inglor_cz 2y ago
  But fertility dropped. May be a contributing factor.
- hansvm 2y ago
  Or not bad enough to overcome other benefits that came out around the same time.
- thoroughburro 2y ago
  “Accumulation” is a keyword you might want to examine.
- littlestymaar 2y ago
  This argument makes no sense, life expectancy increased a lot after the invention of leaded gasoline†, yet nobody would say it's harmless. [†]: Works as well for high fructose corn syrup or Fentanyl.
  - stevenAthompson 2y ago
    I'm not saying it's harmless, I'm saying that even if it is harmful it's not by enough to justify the panic and sudden lifestyle changes these articles sometimes lead to. Remember the black spatulas a while back, and how it turned out to be a math error?
    - wonnage 2y ago
      Is scooping out your food out of the crappy plastic takeout container into a bowl before microwaving an example of “panic and sudden lifestyle changes”? Seems like a pretty minor change to me. I’m already going out of my way to not put metal in there anyway…
    - 2y ago

rendaw 2y ago

Can the body break down cellulose though? It can't digest it at least. And do reactions that could use naturally occurring iron compounds work with steel alloys designed to be non-reactive? I think something else that doesn't get mentioned is it's not just the risk of microplastics reacting, the physical non-reactive presence of particles can clog and get in the way of natural processes mechanically. So nonreactive shouldn't be taken to imply harmless.

Suppafly 2y ago
>the physical non-reactive presence of particles can clog and get in the way of natural processes mechanically Source?
- rendaw 2y ago
  TBH I can't remember what I was looking up when I first read about that (I feel like it was metals, glass, or cellulose again), but https://www.pnas.org/doi/10.1073/pnas.2104610118 https://www.pnas.org/doi/10.1073/pnas.2104610118 seems pertinent: > In general, mechanical interactions of microparticles and nanoparticles on biological membranes are vaguely studied, despite their importance for biological systems (29, 41). Hereby, we will demonstrate that these microplastics induce a mechanical stress of model cell membrane without the need of indirect assumptions about biological pathways (26, 27).
skirmish 2y ago
> physical non-reactive presence of particles can clog and get in the way of natural processes mechanically That would mean fiber in food is harmful since it is not digested. Cellulose is just a common type of natural fiber. Meanwhile: USDA recommends that people consume the following amounts of fiber per day: -- Women ages 31–50: 25 grams -- Men ages 31–50: 38 grams
atombender 2y ago
No, it can't. Cellulose is the main type of insoluble dietary fiber, and is in leafy vegetables, beans, peas, and many other foods. It's widely accepted as being good for digestion. Too much fiber can cause constipation and gas, but most people probably don't get enough fiber, so that's rarely a problem.

sillyfluke 2y ago

The reason for "why microplastics?" is because human use of everyday objects are more plastic than wood or steel. The reason for "why teabags?" is because of previous studies and because I think tea makes it to the top five of the most ingested liquid list. I seem to recall a recent study of microplastic levels in a general population, where people with higher microplastic levels seemed to be tea drinkers, which took some by surprise at the time. I think the population under study was from latin america, if I'm not mistaken. Since this study now has flooded the search results, I'm having trouble finding that specific study. Be that as it may, it's likely that there is a focus on tea because tea-drinkers scored high on microplastics in previous studies.

fy20 2y ago
> The reason for "why microplastics?" is because human use of everyday objects are more plastic than wood or steel. Over the past few decades there has been a trend for plastic based materials replacing natural materials in everyday things. Polyester textiles: Found in most clothing, bedding, and furniture upholstery. Polyurethane coatings: Applied on wooden furniture to give it a glossy, durable finish. Vinyl flooring and tiles: Replacing traditional wood or ceramic options in many homes. Nylon carpets and rugs. Synthetic leather (PU or PVC): Found in everything from sofas to shoes, replacing genuine leather. It's got to a point where it's now hard to find natural materials in some categories. My wife was looking for a new sweater and most shops only had polyester or acrylic.

lkbm 2y ago

> "Microwood" is basically just cellulose, aka insoluble fiber, which naturally exists in our food. This is one thing that confused me about the first article I saw on this. The paper lists three things it detected, one being cellulose, and various articles will list them all together as if they're just three microplastics to be worried about. The paper seems to encourage this reading with this line: "the third one (from the supermarket) being cellulose (CL, sample 3), a bio-based polymer"[0]. Was sample 3 completely fine? If so, why is say "Nanoplastics were obtained from three teabag brands during a standard preparation"? Are they classing cellulose as nanoplastics? [0] https://www.sciencedirect.com/science/article/pii/S0045653524026377?via%3Dihub https://www.sciencedirect.com/science/article/pii/S004565352...

giantg2 2y ago

We know that some plastics mimic hormones (eg estrogens), which can cause problems (eg estrogenic cancers).

thayne 2y ago

> "Microsteel" is just elemental iron which is a necessary nutrient. Steel also contains carbon and if it is stainless steel it also has chromium and probably other metals.

SoftTalker 2y ago
The body does need trace amounts of chromium.

llm_trw 2y ago

Wasn't asbestos non reactive?

userbinator 2y ago

Microplastics are novel hydrocarbons that don't exist in nature. They are short-chain hydrocarbons, which most definitely exist in nature. https://en.wikipedia.org/wiki/Petroleum_seep https://en.wikipedia.org/wiki/Petroleum_seep