New York's decision to ban fracking for health reasons could reverberate beyond the state, bolstering other efforts to limit the controversial method of drilling for oil and natural gas.

While two dozen U.S. municipalities and at least two countries, Bulgaria and France, have also adopted bans, states have been slower to act. Fracking opponents say New York, which surprised them Wednesday with the boldest move of any state so far, will change that.

"It definitely has a national political impact … It really has a domino effect," says Deb Nardone, director of the Sierra Club's Keeping Dirty Fuels in the Ground initiative.

She and other activists say the measure could intensify pressure to roll back nascent fracking plans in California, Illinois, Maryland, and North Carolina, and to help secure a permanent ban in the Delaware River Basin, which supplies drinking water for nearly a thousand community water systems in the mid-Atlantic region. It could also buoy efforts in various state legislatures, many of which return for a new session in January.

Boon or Bust?

The anti-fracking campaign still faces stiff odds. Fracking—aka hydraulic fracturing—has fueled a U.S. energy boom and revived the economies of some states, such as North Dakota, and many communities.

Yet studies have found groundwater contamination and air pollution near fracking sites, increasing the risk of cancer, birth defects, skin rashes, and upper respiratory problems.