>Roughly 50% of indoor dust is composed of microplastics, so it's not like it's uncommon.
I highly doubt that. Soil, skin and pollen are usually the big ones. Hairs depending one how you count dust, but eliminating hair like fibres would also eliminate most of the sources of plastic, unless you allow really large particle sizes.
[edit] Checking research. The highest claim I found was 39% of fibres (in household dust, Japan). but that seemed to be per particle not by volume.
Synthetic fibers from clothes are microplastics, and clothes shed lots of fibers. Not to mention all the upholstered furniture, carpet, rugs, drapes, bags, etc.
That's why I said
>eliminating hair like fibres would also eliminate most of the sources of plastic
If you allow fibres they'd be 0.01% of fibres if you've got a dog anything like mine.
Dog, ha. Try a longhair cat. You'll be extracting balls of fur from most unexpected body cavities.