When you wash a piece of polyester or microfiber in a washing machine you are sending millions of little microscopic pieces of plastic into the water supply.
Ever drink from a plastic water bottle that sat in a hot car and it tastes really funny? Enjoy your plastic.
If you google "plastic in the air", "plastic in food", "plastic in animals", "plastic in water", it's pretty much impossible to not find evidence. It's incredibly depressing. It's in the Mariana trench and on Everest.