PITTSBURGH — Many people in New York and Pennsylvania have voiced concerns about the safety of hydraulic fracturing for natural gas or fracking. But two new surveys found that many people who live in New York City and the suburbs approve of drilling in parts of that state, and that Pennsylvania residents who live in an area of heavy drilling feel the benefits outweigh the risks.

Siena College, which is just outside Albany, said this week that a poll of 822 registered New York voters taken in late November found 50 percent of respondents in suburban areas support drilling in upstate portions the state, while 32 percent are opposed. In New York City, 41 percent of those surveyed support upstate drilling, while 29 percent are opposed. The poll didn’t break out particular suburbs or upstate areas.

New York has had a moratorium on fracking since 2008, but Gov. Andrew Cuomo has suggested that it be allowed in five upstate counties near the Pennsylvania line, far from New York City, its watershed, or major suburbs. Pennsylvania officials from both political parties have embraced fracking, and more than 3,000 wells have been drilled there since 2007.

“Right now what we see is that downstaters, who would be the least affected from both the environmental and jobs point of view, are much more supportive than upstaters,” said Steven Greenberg of the Siena College Poll.

Sandra Steingraber, an anti-drilling activist who lives in Tompkins County, just north of the five-county region likely to see the first drilling, said upstate residents are more likely to be opposed because they’ve learned so much about the issue during four years of intense debate.

About 40 upstate communities in New York have passed bans on fracking, usually at the behest of opposition groups that have circulated petitions. There are movements under way in about 90 more communities to ban or enact moratoriums, but almost all are in towns outside the most likely drilling area near the border. Court challenges are pending against three of the bans with the industry arguing that only the state has authority to regulate gas drilling.

About 60 communities, most of them in the five-county region that Cuomo has suggested might be opened to drilling, have passed resolutions saying they won’t ban fracking but will instead defer to the state’s authority to regulate the industry.

Overall, more upstate New York residents opposed drilling in the poll — 45 percent — compared to 39 percent who favor it, Greenberg said, but they weren’t able to specifically break out the opinions of people in the region where some local governments support fracking.

But a survey in Pennsylvania did just that.

The University of Pittsburgh Center for Social and Urban Research asked similar questions to 403 people in Washington County, which has about 600 gas wells and is about 25 miles south of Pittsburgh.

Forty-nine percent of the residents sampled strongly or somewhat supported the boom, and 22 percent didn’t care much one way or another. Just 10 percent were strongly opposed to drilling, while another 19 percent were somewhat opposed. Those results run contrary to the claims of many anti-drilling activists, who say fracking does more damage to communities than good.

Just over 76 percent in Washington County said drilling offered significant or moderate economic opportunities, and almost 32 percent had a family member who had signed a lease with a gas drilling company. But almost 24 percent still thought drilling represents a significant threat to the environment, while 34 percent thought it was a moderate threat. Forty-two percent thought it was no threat, or a slight one.

The two states have taken different approaches to drilling in the huge Marcellus Shale gas resource that lies beneath large parts of both, as well as under West Virginia, Maryland and Ohio.

Federal energy experts say it became the most productive natural gas field in the country this fall. About 3,500 wells are producing gas in Pennsylvania and Ohio, and the wellhead value this year is estimated to be in the $7 or $8 billion range, even though there’s still no drilling in many places.

While fracking has made it possible to tap into deep reserves of gas, it has also raised concerns about pollution. Large volumes of water, along with sand and hazardous chemicals, are injected underground to break rock apart and free the oil and gas. Regulators in Pennsylvania and other states with heavy drilling contend that overall, water and air pollution problems are rare. New York put a moratorium on fracking in 2008, and is trying to decide whether to proceed.

Many environmental groups and some scientists say there hasn’t been enough research on potential water and air pollution, while the industry and federal officials say the practice is safe when done properly.

Paul Sabin, who teaches environmental history at Yale University, has studied how communities in Pennsylvania, California and the Amazon react to natural resource extraction. He said scholars don’t agree on why some communities welcome an activity such as gas drilling, while others are passionately opposed.

“This is a more difficult question than it seems,” Sabin wrote in an email, adding that economic, cultural and political factors have been suggested.

Many drillers who have already found highly productive wells near the New York border have been hoping that state will allow them to expand operations.

Kathryn Klaber, president of the Marcellus Shale Coalition, an industry group, noted that New York residents already use large quantities of gas that comes from fracked wells in other states. She noted that NYC Mayor Michael Bloomberg has said that expanded natural gas use “makes good economic and environmental sense.”

“We absolutely agree, and believe that New York should move forward with common sense shale gas regulations that ensure more of these benefits are broadly realized,” Klaber said in a statement.

Patrick Henderson, Pennsylvania’s energy executive in the governor’s office, said the Siena poll shows that New Yorkers “see in Pennsylvania and other states the ability to develop this resource responsibly while protecting the environment.”