No one says a word bout disposable diapers. By volume, I would guess that they are a much larger problem than anything else plastic.
Plastic grocery bags DO dissolve in less than 3 years. Cornstarch is in them now, and I have ones in my garage that are flaking apart.
A few years ago I remember reading that environmental groups gave up about trying to get people to not use disposable diapers. The convenience was just too great to not use them.
I see it as a tourism, recreation thing.
Eventually our landfills in Indiana will provide some awesome winter sports slopes.