IN JUST TWO YEARS, the nickel tax on plastic bags in the District has proved highly effective in fighting environmental degradation and prompting people to choose reusable bags over plastic, thereby reducing litter and beautifying local woods, waterways and roads. The ease of the measure’s implementation has made a mockery of the arguments deployed against it when it was debated.

The overwhelmingly positive evidence in the District should be enough to persuade lawmakers in Annapolis to shed their jitters and enact similar legislation in Maryland. But a full-court press by special interests is threatening to derail what would be a major step forward in the fight to clean up the environment in Prince George’s County and throughout the state.

The special interests, led by plastic-bag manufacturers, are spending heavily and mustering bogus arguments to defeat a bag tax for Prince George’s that received overwhelming support from the County Council. Critical votes are scheduled in the coming days that will determine a simple question: Do lawmakers favor cleaning up the environment or sustaining profits for one narrow industry?

Montgomery County followed the District’s lead last year in adopting a bag tax, and county officials in Prince George’s favor such a tax, too. But before Prince George’s can go forward, it needs enabling legislation — in effect, permission — from state legislators. If the state’s second-largest jurisdiction joins Montgomery, the largest, that would shift Maryland toward a tipping point where approval of a statewide bag tax would be within reach.

With one lawmaker absent, the measure failed by a single votewhen state lawmakers from Prince George’s considered it Wednesday. It is scheduled for a re-vote next week. It’s crucial that County Executive Rushern L. Baker III (D), who favors a bag tax, mount his own lobbying effort to counter the disinformation.

Playing fast and loose with the facts, the plastic-bag industry has whipped up hysteria by arguing that a bag tax would hurt poor people in Prince George’s, who, industry officials suggest, would be incapable of using reusable bags instead of plastic ones. That’s nonsense. In the District, where the poverty rate is more than twice that in Prince George’s, there was an 80 percent drop in plastic-bag use in 2010 as people switched to reusable bags.

Bag-tax opponents are using another scare tactic, warning that reusable bags could harbor dangerous germs. But no adverse health impact has been recorded in the District, let alone in Europe, where reusable bags have been in fashion for decades.

A bag tax is a no-brainer; it has worked, and worked well, wherever it’s been adopted. Consumers have proved highly adaptable and quite willing to help the environment by shopping with reusable bags. And the results are clear: a sharp drop in plastic bags entangled in trees, floating in rivers and blowing down the streets like tumbleweed.