Microplastic accumulation in the body makes me wonder if natural biopolymers could have the same problem. We cannot break down cellulose; what happens to micro-cellulose in the body? Or lignin, which is even more refractory to decomposition?
Do plant microfibers accumulate in the body over time, like plastic or asbestos fibers? Do we end up loaded with this stuff in old age?
One of the most lethal professions of old was baker, because of all the flour dust inhaled.
The breakdown of lignin by fungi shows the lengths organisms have to go to decompose refractory organic materials. A whole suite of enzymes and associated compounds are released into the extracellular environment by these fungi, including hydrogen peroxide, some of which is decomposed to highly oxidizing hydroxyl radicals. This also shows why it should not be surprising fungi are capable of attacking plastics, at least to some extent: they are already blasting biopolymers with a barrage of non-specific highly reactive oxidants.
> Microplastic accumulation in the body makes me wonder if natural biopolymers could have the same problem. We cannot break down cellulose; what happens to micro-cellulose in the body? Or lignin, which is even more refractory to decomposition?
We have a lot of defenses to make sure large molecules don't make it into the bloodstream so if those polymers start making it through, we'd have much bigger problems. Microplastics are a special case because they're very chemically inert, but they're still filtered out by the kidneys. Any cellulose or lignin would be too.
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.
> One of the most lethal professions of old was baker, because of all the flour dust inhaled.
Pretty much anything that is small enough to irritate the lungs will cause the same effect, especially at professional exposure levels (or worse, like silicosis). Pre-industrial agricultural workers and miners frequently suffered from pneumoconiosis from dust inhalation too, for example.
Yeah, I’ve started to get a bit cautious about the quality control in these papers too… not because I doubt there’s a problem, but that I suspect it’s all too easy to ignore the quality control necessary to ensure lack of contamination when the researchers go in looking for a positive result… it’s a “cheap win” and I don’t like it…
I’d like to see some reproduction research on the more wild microplastics results akin to the level of diligence put in when Clair Cameron Patterson was developing Uranium Lead dating and discovered that due to lead added to petroleum based fuels the whole fucking planet was tainted with a level of background lead … he had to go a long way, basically building a clean room before such rooms were considered a normal part of precision research… to get a clean environment with no contamination and get accurate results.
It doesn’t have to be quite that bad for a modern researcher, but I’d like to see a lot more of these microplastics papers where they document that they used no or as close to no plastic at any point in sample handling… if a liquid sample has gone from a plastic sample jar and a plastic lid to a plastic pippet to a plastic ampoule with a plastic lid into a machine that agitated it and so on… well of course there’s a damn chance the sample has more plastic in it! I’m not even going to suggest that all the plastic came from the containers that would be stupid… but when I start seeing results like microplastic found in human testicular tissue… I want to know how careful they were with sample contamination because it’s important that we know how bad the problem is getting, is it “1000” or “1002” on whatever scale is being used may not seem like much when the error bars might be +/- 10… but it does matter when this result gets aggregated into meta analysis and other modern “re-processing” that helps us understand the world at the larger scale where studies of aggregate data are the only practical way to approach the problems.
Macrophages are cells that take care of stuff like eating splinters that you can't get out.
What if there was something we could eat that basically super-powered our macrophages to to it for us? They already eat the microplastics but they just sit inside them.[1] Digesting them might be poisonous I guess ...
What would that be though? The macrophages would have to be supplied with the correct chemical? Seems like it would be easier to inject a fungus that can co exist with our cells. I recently read about Lichen in Sheldrake’s Entangled Life and how Lichen is not a single species or even in a single kingdom because it consists of a community of fungus and algae. In the same way that our cells encapsulated mitochondria, I wonder if the macrophages could work well with a (genetically modified?) fungi strain that could digest the plastic. I know this is far out and I’m hoping an expert on the subject could tell me if this has ever been discussed. Most people see fungus as a health threat but it’s an entire kingdom that we’ve only scratched the surface of understanding. If I were to go back to school I would probably study mycology.
This is not a bad idea. The lysosomes in cells use some fairly intense chemicals to hydrolyse biopolymers, and macrophages produce oxidants like hypochlorite. But then, inflammation is a risk factor for cancer, perhaps because of side effects of those oxidants.
Yeah I hope I don’t give anyone ideas. You could make a lot of money selling mushroom supplements that supposedly contain the same fungus studied in this research.
I don't think I'd want my internals exposed to the stuff fungi have to excrete to break down the fibers. Fenton chemistry is used to clean lab glassware, I think.
Well microplastics are micro after all, so maybe the byproduct would only be present in small amounts that the body can absorb? Chemotherapy is rough on the body but if the end result is that the cancer is removed it’s generally seen as a valid trade off. Unfortunately I’m not very knowledgeable about chemistry.
Chemotherapy is rough on the body because it's specifically targeted to disrupt the process of growing new cells, destroying them when they form. Your body produces new cells much slower than cancer does (by definition), so it can weather the poison longer (in theory).
There's no reason to expect this to be the analogy to hold for reactive chemicals capable of decomposing organic polymers, which are generally tougher to decompose than our also-organic cells.
Good point. Whenever I think about how much I'm poisoning myself with plastics or breathing exhaust or whatever I remind myself what I did last Friday night and it's like ... yeah this pales in comparison.
Well if you’re drinking heavily or something similar yes it might be worse than microplastics. But the scary thing about microplastics is that they accumulate with time, and we still don’t know what effects they’re having on the human body. I find that to be frightening in a very existential way, similar to thawing permafrost or nuclear Armageddon, lol. You can’t escape it, and statistically it’s probably ruining millions of people’s health across the world.
That's a good point. You can escape vaping questionable hemp products a lot easier than you can avoid being a walking, talking heavy metal filter for the local coal plant.
> Dietary cellulose is an insoluble fiber and consists exclusively of unbranched β-1,4-linked glucose monomers. It is the major component of plant cell walls and thus a prominent fiber in grains, vegetables and fruits. Whereas the importance of cellulolytic bacteria for ruminants was described already in the 1960s, it still remains enigmatic whether the fermentation of cellulose has physiological effects in monogastric mammals. [6–11] Under experimental conditions, it has been shown that the amount of dietary cellulose influences the richness of the colonic microbiota, the intestinal architecture, metabolic functions and susceptibility to colitis. [12,13] Moreover, mice fed a cellulose-enriched diet were protected from experimental autoimmune encephalomyelitis (EAE) through changes in their microbial and metabolic profiles and reduced numbers of pro-inflammatory T cells.
Microplastic concentration is highest in the lungs, but can also be found in the blood. As far as I know, we do not know how long they persist in the lung, blood, or body more generally.
Given their ubiquity, and their endocrine disrupting properties, I highly suspect that the rise in autism prevalence may in part be attributed to the prenatal exposures to microplastics, during which timing and dose effects of androgens exposures have set-up long lasting programs of development.
Re bakers, I did not know about that. Very interesting.
Do plant microfibers accumulate in the body over time, like plastic or asbestos fibers? Do we end up loaded with this stuff in old age?
One of the most lethal professions of old was baker, because of all the flour dust inhaled.
The breakdown of lignin by fungi shows the lengths organisms have to go to decompose refractory organic materials. A whole suite of enzymes and associated compounds are released into the extracellular environment by these fungi, including hydrogen peroxide, some of which is decomposed to highly oxidizing hydroxyl radicals. This also shows why it should not be surprising fungi are capable of attacking plastics, at least to some extent: they are already blasting biopolymers with a barrage of non-specific highly reactive oxidants.