I’d argue that’s just shifting the burden of proof. I’d like corporations to prove that something isn’t dangerous before they put it in the food I eat.

Besides, if other microparticles are dangerous, I’d rather not have even more of those, especially ones that haven’t been through thousands of years of human evolution.

I understand your claim; so we have lived forever with a baseline stroke risk (maybe zero) that is attributable to these microparticles. The addition of plastics, because they may block, will not certainly lower our baseline risk, and may (as this evidence suggests) increase it.