The ever-fertile mind of Portland City Commissioner Sam Adams has turned to solving one of life's vexing dilemmas: "Paper or plastic?"

Two weeks after San Francisco became the first U.S. city to ban plastic grocery bags, Adams is weighing whether to ask the Portland City Council to seek an outright ban on the bags, a tax on them, or merely a voluntary commitment from grocers to reduce their use.

"We should have done this a long time ago," Adams says.

Made from nonbiodegradable polyethylene, the bags are hard to recycle and mostly end up in landfills. South Africa, Bangladesh, Taiwan and France have banned them. And, in Ireland, a 20-cent plastic bag tax has pushed them to near-extinction in that country.

As of Monday, an informal, unscientific poll on Adams' blog showed 64 percent support for a ban, 18 percent for a tax, 10 percent for a voluntary campaign, and 8 percent for doing nothing.

Most Portland grocers, both big-box and boutique, weren't thrilled about a ban or tax at a meeting Tuesday with Adams. Zupan's, New Seasons, Fred Meyer and Whole Foods all defended the status quo, issuing warnings that customers could go outside Portland to buy groceries, and of a tax hurting the poor. But Safeway spokeswoman Bridget Flanagan says she doesn't understand that opposition, since consumers would have the choice not to pay a tax by opting for paper.

Plastic was crowding paper out of grocery stores when the Oregon Legislature came to paper-bag makers' rescue in 1991 with a law that said grocers must offer paper bags if they offer plastic, and must inform customers they have a choice.

Such choice carries an environmental cost.

Trees are cut down to make pulp, and paper-making is polluting and energy-intensive whether virgin or recycled pulp is used. Plastic bags take much less energy to make but come from petroleum—enough in 14 plastic bags to drive a mile in a car. Also, they don't break down easily, contribute to litter, and pose a recycling challenge.

"They're definitely recyclable, but they're a problem for us," says Jeff Murray, vice president of Far West Fibers Inc., the Portland area's largest recycler. Loose bags get caught in the sorting machines, Murray says, and must be removed with special knives, a hazardous and time-consuming task.

Recyclers likely will stay out of the Portland debate, Murray says, except to say they don't like San Francisco's ban, which applies only to plastic bags made from petroleum. That leaves the door open to plastics made from other things, and mixing the two would foul up recycling pretty badly, Murray adds.

Portland isn't alone in looking at paper vs. plastic. Eight other cities are considering the question. Adams remains ready to commit Portland to paper bags, and seems willing to brave any possible repeat of the flap from fast-food joints when Portland enacted a styrofoam ban in 1990.

"Fast-food places said it would be the end of the world as we knew it," Adams says. "But life went on."