“The median concentration in brain samples collected from people who died in 2024 was nearly 5,000 micrograms of plastic per gram of brain tissue, tallying almost 0.5% by weight.”
Brains from 2024 held about 0.5% plastic by weight, roughly 50% more than samples from 2016. Brains of people with dementia held three to five times more. The study says causation is not established. The trend still points one way.