Growing up there was this punk house in my town I spent a lot of time at. For some reason they had a giant bag of packing peanuts, and someone said they were edible. We proceeded to eat a fair number of them. Not like a ton, but probably a few each. Definitely more styrofoam than a person should eat.
There was also a small trampoline in the living room and I remember one day where it was declared acceptable to nut-punch each other. Just adding that to give context for the collective genius at work there.
Anyway, I guess that was my body's introduction to microplastic.