Boston is the latest city to ban plastic bags after Mayor Marty Walsh announced on Sunday he signed a city-wide ordinance.

Walsh told Boston 25 News he signed the ban on Friday after the City Council unanimously had approved it last month.

Walsh says he supports the ban because of it's environmental benefits, but that he's still concerned about the impact this will have on the poor.

The ban encourages shoppers to use reusable bags or pay a $.05 fee for compostable plastic bags or paper bags.

Paper bags without handles would still be free and businesses would keep all bag fee proceeds.

The ban will go into effect next fall.

Walsh spoke about his concerns regarding the ban while attending the Christmas in the City event, and pointed out the ban affected local families.

"We're here today at Christmas in the City, many of these families that are here are on a fixed income, a dollar a bag or fifty cents a bag, five cents a bag on top of all the other charges that people have to pay -- that adds up.”

The Associated Press contributed to this report.