Something nobody has mentioned trying is collecting particle samples on some sticky tape and then looking at it under a microscope. From what I’ve read, 0.2 micron is the limit of what’s visible, so maybe with a microscope camera you could see 0.3 micron particles, and larger of course.
Just an idea. Not sure how practical it is, but for some people it might make the topic more real if they could see the stuff they’re breathing in. I’ve read some sketchy studies that even without 3D printing, there’s a wide range of estimates that something like, on average, 29 to 250 grams of microplastics get into our bloodstream over the course of a year, without any clear mechanism for dealing with it and with as yet unknown consequences.