Most people aren’t aware that their synthetic clothes are made from plastics/petroleum products. But even if you knew that, maybe you didn’t think about what happens when you wash them. Although we got rid of the vast majority of non-natural fabrics (still have some, but very few) from our wardrobes and linen closets a few years back, I had never actually thought about their effects on the waters of the world when we wash them. But it makes sense, since I know our clothes are always breaking the fibres down when we wash (or dry via the dryer).
A side note: I’ve noticed that when I use the dryer, I have no need for fabric softener of any sort, and I think that is because our clothes are all natural fabrics. The static electricity builds up on the man-made items, not our cotton, linen, hemp.