The average brain weighs 1300-1400 grams. If 0.5% of that is plastic by weight, your brain contains 6.5 - 7 grams of plastic. The average plastic credit card weighs 5 grams.
https://www.theguardian.com/environment/article/2024/aug/21/microplastics-brain-pollution-health
I'm saying the weight is, and it's not just my skull, it's everyone's skull. It's likely we're all experiencing those issues. It's also not up there in a single slab, but embedded throughout, which hopefully mitigates that issue.
A study under peer review claims those with dementia are more likely to have more plastic in their brains than the average person.
You're good, just wanted to be clear.