That… actually doesn’t seem as bad as I thought it would be. Obviously it’s not going to be evenly spread across the globe, but that’s about (napkin math) 350μg/m^2/year. Even over a century that’s barely a light dusting (to be fair, of toxic/carcinogenic/etc microplastics that are likely much more highly concentrated around major highways and population centres, and their waterways).

I always assumed it was orders of magnitude more than that. But that seems like an amount that, if it were to exist, some sort of bacteria/fungus/algae could actually probably handle.