Unintended consequences are interesting phenomena. They are the unplanned bad things that happen when you try to do something good.
It appears that banning one-use plastic grocery bags, and thereby encouraging the use of cloth reusable bags, brings about increased salmonella and norovirus infections. See this Bloomberg article for details.
These infections are logical outcomes of using dirty bags. Plus the ban forces people to buy plastic bags to use as garbage bags when they formerly reused old grocery bags for this purpose. Net environmental outcome ... essentially zero. Health outcome ... negative.
