I tried to write the most biased scaremongering paper about microplastics for a college course and I couldn’t find much directly linking human health to microplastics that was peer reviewed.
The main paper in this article, the one claiming its human brain samples are 0.5% plastic, is preprint - not peer reviewed. So, reporting on it like this is unethical tbh.
Truthfully, scientists have been looking for this sort of link in animals, and they can’t find earthshaking evidence of it. Most of the papers I found showed weak evidence of harm to animals. Most of the scarier papers have to do with how these plastics absorb chemical pollution in sea water, fish then eat the particles and are harmed. These papers point out they have trouble separating general harm from pollution from harm from microplastics pollution.
Microplastics don’t seem to go up the food chain either, seems most plastics people eat are introduced through processing it. So, stop eating processed food. Stop wearing polyester while you’re at it, a lot of microplastics come from laundry.
I’m not saying microplastics aren’t bad for human health. It’s just incredibly hard to study and it’s definitely not as bad as lead or asbestos. If it was, scientists would have found that link already.
The worst news I ran across was that there is no human control group for this stuff. Everyone is full of microplastics. Those are the only peer reviewed human studies this article mentions - the sort that are like “Of samples from 20 different people, they were all full of plastics! We need grant money for more study”.