I've quickly scanned the paper. It convincingly shows that nanoplastics can promote aggregation of α-synuclein (a key protein in Parkinson's pathology) in vitro and in cultured cells. Note however that many substances known to be safe can do this.

The in vivo study involves injecting nanoplastics directly into the brain of mice along with human α-synuclein fibrils, so is one step up from in vitro work but still quite artificial.

In sum, it does not demonstrate that nanoplastics in the environment, or even those that might be directly administered to mice, e.g. in food, have any effect on Parkinson's-like symptoms or pathology.

Edit: I should add that laboratory mice are often in contact with plastics that they chew on. So it's highly unlikely that ingesting plastics has any effect on mouse models of Parkinson's as this would have been noted decades ago.

> laboratory mice are often in contact with plastics that they chew on. So it's highly unlikely that ingesting plastics has any effect on mouse models of Parkinson's as this would have been noted decades ago

Doesn't it only mean there were no control group? Just like when they found out that mice suddenly started dying less when they raised lab temp a bit.

In this case they directly injected the nanoplastics + α-synuclein into the brains of one group and as a control injected only α-synuclein.

However, mice that have human α-synuclein have been around for decades, and nobody has (so far) noticed any effect of plastics on the development of Parkinsonism in these mice, neither are there any claims that Parkinsonism is more prevalent in people who have plastic implants of one kind or another.

Note that people ingest plastics all the time, e.g. through the breakdown of toothbrush bristles.

> Note that people ingest plastics all the time, e.g. through the breakdown of toothbrush bristles

Plastics are found in human blood/lungs/breast milk/placenta etc, so the concern is much stronger than just accidental ingestion from a toothbrush.

Read about effects of xenoestrogens, which a bunch of these plastics apparentlt are, and cross check with some realities of today.

>xenoestrogens

Yes, I appreciate the risk of plasticisers, and these should be addressed.

However, by the time an item made of plastic has become a "microplastic", these plasticisers have been leached out.

BPA is not a plasticizer.

Here’s the version in Science Advances: https://www.science.org/doi/10.1126/sciadv.adi8716

I'll wait for this to be TLDR'ed through ChatGPT. It uses a lot of high speak, it seems to conclude that nano-particles not just plastics have an effect on proximity to neurons under the right conditions.