> > but there's little evidence that they're (...) harming health

> "The combined data, although fragmentary, indicate that exposure to micro- and nanoplastics can induce oxidative stress, potentially resulting in cellular damage and an increased vulnerability to develop neuronal disorders."

I.e. just like GP said, there's little evidence. Not a complete nothingburger, but also nothing that enables you to truthfully say "microplastics are harming health" in a nontrivial sense, demanding priority attention.

Note the language used in the abstract you quoted: "can induce oxidative stress, potentially resulting in cellular damage and an increased vulnerability to develop neuronal disorders" (emphasis mine). The very next sentence continues: "Additionally, exposure to micro- and nanoplastics can result in inhibition of acetylcholinesterase activity and altered neurotransmitter levels, which both may contribute to the reported behavioral changes." (emphasis again mine).

"Can", "potentially resulting", "increased vulnerability", "may contribute" - this language is very deliberate: "Can" means, it also could not, or could sometimes not; the potential in "potentially resulting" may not realize; "increased vulnerability" is true even if the increase is completely insignificant; "may contribute" doesn't say which way, or how much. Scientific papers use such constructs to hint at potentiality without committing to it. A big shmaybe.

(Politicians and marketers and activists (and small children) use this kind of language too, relying on the audience to miss the hedge, so they can convince people to believe in lies, without technically lying to them.)

Conversely, when someone has something concrete to say, they don't hedge like this - instead, they say "does", "results in", "causes X under conditions Y", "increases vulnerability by Z", "contributes to U", etc.

So, in short, no: the bit of abstract you quoted isn't refuting GP's point, but actually confirming it. Microplastics are a pure distraction.

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In case you have doubts, I recommend reading the full text of the article[0]. All those hedges are made more concrete in the article body - some in the analysis of prior work, others in the conclusion. Interesting quotes:

"Moreover, the potential health risks resulting from micro- and nanoplastics exposure, uptake and translocation is poorly investigated and is an important matter of ongoing debate [14, 18, 34,35,36]." (From "Background")

"The extent to which these effects are also applicable to micro- and nanoplastics is however largely unknown." (From "Main text")

"In striking contrast to the relative wealth of available rodent in vivo studies with metal(oxide) nanoparticles, there are only two studies that investigated the neurotoxicity of micro- and nanoplastics in rodents. This is particularly striking given the observed neurotoxic effects of exposure to micro- and nanoplastics in fish and (marine) invertebrates." (From "Neurotoxic effects of micro- and nanoplastics in rodents")

"Information regarding levels of small plastic particles in the environment, (drinking) water and food chain are still scarce and often only limited quality criteria are reported. More and improved data on the occurrence of small plastics particles in the different environmental matrices is needed to reliably estimate human exposure and aid hazard and risk assessment, and current efforts aim at harmonizing monitoring methods and quality criteria [106,107,108]." (From "Reflections on and potential implications of neurotoxicity induced by micro- and nanoplastics")

"The concentrations of micro- and nanoplastics used in experimental studies are often (much) higher than those currently found in the (aquatic) environment. (...) Unfortunately, the dose is often expressed as weight/volume, without info on particle density. Consequently, information regarding particle numbers is often unknown. Although exact details on human intake of micro- and nanoplastics are often also unknown, these are likely to be much lower. (...) Notably, while some information is available on (human) intake, the information regarding uptake and translocation in animals or human is even more scarce. Few of the studies published so far made serious efforts to quantify particle uptake and translocation, so it is often unclear whether or not the particles actually made it to the tissues/systemic circulation, whether or not particles can subsequently be excreted/eliminated, and how uptake and distribution relate to the observed (neurotoxic) effect." (Ibid)

"Notably, most experimental exposures used so far are not very realistic for human exposure. Most studies used short exposure durations, with high exposure levels, while humans are chronically exposed to low levels. Additional shortcomings of the available studies include the use of (virgin) particle types and shapes that are not environmentally relevant. Moreover, a systematic comparison of different particle types, shapes, sizes and concentrations is lacking and to date most research focused on aquatic species." (From "Conclusions")

And there's many, many more statements like this - I recommend reading the full article; I omitted quotes with numbers and details that would require quoting half a page here. The article raises a good point that there is a reason to worry - micro- and nano-plastics have structural similarities to chemically inert metal particles, which are known to be hazardous to health. But while it's rather apparent micro- and nanoplastics are harmful to some degree, whether or not and how big of an issue that is is very much unclear at this point.

The way this is a distraction is because it competes for attention and care with CO₂ emissions and climate change, which is known to be an imminent extinction-level threat. Additionally, some of the proposed mitigations for plastic pollution problems run counter to what's needed to deal with climate change at the moment.

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[0] - https://particleandfibretoxicology.biomedcentral.com/article...