It is not just single use plastic.

Micro plastics from washing clothes:

https://www.sciencedirect.com/science/article/pii/S026974911...

"The number of microfibres released from a typical 5 kg wash load of polyester fabrics was estimated to be over 6,000,000 depending on the type of detergent used"

A lot of study still needs to be done to determine the sources of micro plastics.

We can all stop using single use carrier bags, but can we stop washing our $3 Target t-shirts made from poly-cotton?