@CelloMomOnCars
I suspect the biggest chunk of the synthetic textile portion belongs to industry. Tarps, temporary covers and the like. Synthetic clothes worn normally get a bit of wear through normal life, but industrial facilities put things under "temporary" textile covers until the cover wears out and then they replace the cover. This stuff sits out in full UV all day every day and it wears out due to that exposure much faster than someone's polyester shirt.