If you live in a country that has municipal waste collection, the best thing you can do if you are concerned about plastic pollution is:
1. Don't litter.
2. Switch to clothes made wholly from natural fabrics such as wool or cotton.
The problem with large pieces of plastic in the oceans is mainly caused by people in developing countries who dispose of their trash by throwing it in a river (because the only other choice is to burn it). That's not to say that people in more developed countries don't also contribute to ocean pollution but in developed countries the pollution mainly comes from washing clothes, as large pieces of plastic are safely disposed of by municipal waste collection.
1. Don't litter.
2. Switch to clothes made wholly from natural fabrics such as wool or cotton.
The problem with large pieces of plastic in the oceans is mainly caused by people in developing countries who dispose of their trash by throwing it in a river (because the only other choice is to burn it). That's not to say that people in more developed countries don't also contribute to ocean pollution but in developed countries the pollution mainly comes from washing clothes, as large pieces of plastic are safely disposed of by municipal waste collection.