Was there some sort of scientific breakthrough that has allowed researchers to find these microplastics for the first time, or is it just that nobody had looked yet?
I was wondering the same thing. I saw an article yesterday about scientists just discovering that tea bags release billions of micro and nano particles.
I got the sense it was the nylon bagged tea that had the issue, and they are comparatively rare in the UK. Yet many paper tea bags have tiny amounts of plastic based glue. No idea if that's enough to be feeding us microplastics, or relative quantity to plastic ones.
It's one of those things that having found surprising amounts somewhere, we're going to spend the coming years finding surprising amounts everywhere.
Bit like the chap who ended up finding lead from petrol everywhere on every researcher and clean surface in his lab, invented the clean room, and started finding it up mountains etc.