[dbingham]

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/

> 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

[brokegrammer]

> Almost all the studies on the toxicity of microplastics use experimental models, and the harm to the human body is still unclear.

You missed this part, which is the most important one.

[therealcamino]

So...perhaps worthy of further study, maybe including to understand where exposure comes from, and whether the particles are absorbed? Like this study.

[zug_zug]

Unclear doesn't mean safe, it just means hard to quantify. Your child could be in a car accident and their survival odds could be unclear, scientifically speaking. Doesn't mean "totally safe."

[brokegrammer]

This is the wrong analogy because the article states that there's only theoretical harm. It could mean that one has to drink from 100 tea bags a day to get any adverse effects.

I'd wait for more research before freaking out.

[mjmahone17]

It’s reasonable for people to take either approach: are microplastics more like asbestos or are they more like cellulose in terms of harm?

The answer being unclear means it makes sense to treat them, from a regulatory standpoint, closer to asbestos. It also makes sense to treat them as an unknowable and not regulate, because any alternative might be worse.

But it does point to there being a dearth in research and answers, and we should solve that as quickly as possible and maybe limit our exposure when viable, known to be non-toxic alternatives exist.

[Suppafly]

>The answer being unclear means it makes sense to treat them, from a regulatory standpoint, closer to asbestos.

I'm not sure the follows logically, it ignores a bunch of known facts about biology to imagine that there is a pathway for these to cause major issues.

[schmidtleonard]

Damage that is bad enough becomes easy to quantify, so no, "unclear" actually does put a bound on it.

Survival odds in car crashes demonstrate this nicely: count the outcomes and divide. If "the survival odds were unclear, scientifically speaking" then car accidents would have to be orders of magnitude more rare and less lethal than they are.

[whatshisface]

Sudden damage that is bad enough is easy to quantify. You should take a look at the decades long struggle to prove that cigarettes are harmful to see what it is like when the harm is chronic.

[thayne]

It doesn't mean unsafe either.

[lowbloodsugar]

In what way is it the most important one?

Was the most important part of all the tobacco research the bits that said “Smoking tobacco is healthy”? Or the studies of lead in gasoline the caveats that said “These are small samples”?

[brokegrammer]

It removes the possibility of fear mongering. I'm not aware of any modern research where smoking anything is claimed to be healthy, nor anything about lead in gasoline being too insignificant to pose a health risk.

I prefer fact over fear based science.

[aziaziazi]

> I prefer fact over fear based science

What is that supposed to mean? Most science is based on theories but you don’t wait for the Theory of Everything to take learnings of science. Fear is a very useful emotion and you shouldn’t fear it.

[Yizahi]

You are mistaking "theories" and "hypotheses". Theory in science is not some wild shot in the dark, imagined by some random guy in the eureka moment. And neither it is a something yet unproven. Theories in sciences are usually sufficiently proven and stand on the other previously proven theories. Like for example evolution of species is a theory, despite it having more than a century of research and hard proofs. So yeah, science is based on theories, but not on a collection of lucky guesses.

Now hypothesis is what you were probably mistaking a theory with. A hypothesis is something unproven and may or may not be a real thing.

[aziaziazi]

I did mistaken those, thank you for pointing that out. My point remains that science operates in the real world, where decisions often have to be made based on incomplete evidence, rather than waiting for certainty.