New York Gov. Andrew Cuomo’s (D) administration said Wednesday that it will block gas development by hydraulic fracturing, bringing to an end a six-year study process and kicking off what could be years of lawsuits from developers who want to tap rich Marcellus shale deposits.

At a cabinet meeting Wednesday morning, acting state Health Commissioner Howard Zucker released the results of a years-long study into the public health implications of hydraulic fracturing, or fracking. Zucker said the benefits of tapping natural gas deposits in western New York did not outweigh the potential risk to public health.

“The overall weight of the evidence … demonstrates that there are significant uncertainties about the kinds of adverse health outcomes” associated with fracking, Zucker wrote in the Health Department report [pdf].

New York Environmental Conservation Commissioner Joe Martens, whose department has also undertaken a review of the impacts fracking would have on local communities, said 63 percent of the land available for fracking would not be eligible for high-volume fracking because of health risks, the Rochester Democrat and Chronicle reported.

Industry representatives reacted angrily to Wednesday’s decision, which was announced with little fanfare before the cabinet meeting began.

“This is an ill-advised decision that denies New Yorkers the opportunity to take advantage of the many environmental and economic benefits that natural gas offers,” said Paul Hartman, the Albany-based northeast director of America’s Natural Gas Alliance, the industry trade group. “The decision to prohibit hydraulic fracturing is based on data that does not justify the Cuomo administration’s conclusions.”

Democrats and environmental activists praised Cuomo’s decision Wednesday.

“The Governor based his decision on the science — not the demands of oil and gas drillers looking for a quick buck,” Rep. Carolyn Maloney (D-N.Y.) said in a statement. “The public health risks posed by contamination of our air, land and water are too great to allow high-volume, horizontal fracking in our beautiful state.”

Svante Myrick, mayor of Ithaca, N.Y., which sits atop one part of the Marcellus deposit, said fracking would upset the local tourism industry without bringing much economic benefit.

“Our economy is strong because of our agriculture, tourism and education. Drilling pads dotting our hills, trucks pounding our roads, and the fear of soil and water contamination would threaten our success in all of those areas,” Myrick said. “The gains would be short-term.”

The debate over hydraulic fracturing long predates Cuomo’s tenure. The state legislature passed a measure approving fracking and horizontal wells in 2008, but then-Gov. David Paterson (D) placed a hold on permits for those wells until the Department of Environmental Conservation could report on the impacts. The department issued a draft report in 2009, but Paterson ordered a second draft the following year.

That second draft came in July 2011, after Cuomo had taken office. Martens, the DEC commissioner, said at the time that he believed fracking could be done safely. The DEC started the long process of crafting regulations that would guide high-powered fracking.

But after environmental activists protested, Cuomo ordered another review, this one from the state Health Department, in 2012. The Health Department missed key deadlines in 2013, further delaying the DEC report. The report was still unfinished in October, when, at his only debate with Republican opponent Rob Astorino, Cuomo said it would be finished by year’s end. This Monday, Cuomo reiterated that the report would be ready by the end of the year.

By that point, however, the draft recommending a ban on high-powered fracking had begun circulating among Cuomo administration officials. The administration’s ultimate decision may have been made easier by a Court of Appeals ruling in June that allowed individual towns to use zoning ordinances to prohibit fracking in their areas.

On Wednesday, Cuomo insisted that he was deferring to experts like Zucker and Martens to make the decision for him, rather than considering politics. But the years-long delay angered both environmental activists, who arranged mass protests against fracking at his 2013 State of the State speech, and the gas industry itself.

“This has always been a political, rather than a public health decision,” ANGA’s Hartman said Wednesday.

Indeed, Cuomo’s decision sets him apart from other Democratic governors around the country who have given their approval, however limited, to fracking.

In November, Maryland Gov. Martin O’Malley (D) said he was prepared to allow fracking for natural gas in the Marcellus shale in Western Maryland, though he set out strict public health and environmental rules that developers must follow. Last year, California Gov. Jerry Brown (D) signed fracking regulations into law, which allowed developers to begin exploring shale deposits in his state. The same year, Illinois Gov. Pat Quinn (D) signed a bill that allowed fracking to begin.

Developers have begun fracking for natural gas in other parts of the Marcellus shale deposit, which stretches from upstate New York through Pennsylvania, Ohio, Maryland, West Virginia, Virginia and Kentucky. The U.S. Geological Survey estimated in 2002 that the formation held an estimated 1.9 trillion cubic feet of natural gas.