Microplastics are fragments of any type of plastic[1] less than 5 mm (0.20 in) in length, according to the U.S. National Oceanic and Atmospheric Administration (NOAA)[2][3] and the European Chemicals Agency.[4] They cause pollution by entering natural ecosystems from a variety of sources, including cosmetics, clothing, and industrial processes.
https://en.m.wikipedia.org/wiki/Microplastics
Plastic clothing fibers would make this up, too. Take a look at the dust around you or on your furnace filters, and you’ll see a bunch of lint, made up of skin cells and mostly small clothing fibers.
Sorry, I should have used the sarcasm tag.
The point of my intended sarcasm was that by only estimating the length (less than 5mm), the writers “buried the lead” - namely, that these tiny fragments are nearly invisible, and weightless enough to float in the air and unknowingly be inhaled or ingested.
In order to properly convey that property, the far more relevant dimension to offer would have been the estimated breadth - not the length.
I’ve been told I have a weird sense of humor.
I just thought it was funny picturing everyone brainlessly filling themselves up with 3/16” bits of plastic.