WRITE and CALL Governor Cuomo that you want PUBLIC INPUT, RECOGNIZED EXPERTS USED and a TRANSPARENT PROCESS.

After four years of study by the state, the Cuomo administration now says its decision on whether to allow high-volume hydraulic fracturing in New York will have to wait until it conducts a review of the potential public health effects of the controversial natural gasdrilling process.

On Thursday, Joseph Martens, commissioner of the State Department of Environmental Conservation, announced that he had asked the health commissioner, Dr. Nirav Shah, to assess his department’s analysis of the health effects closely.

Mr. Martens said he was responding to widespread concerns that the state had not adequately addressed potential health consequences in its environmental assessments as it moved toward a decision on whether to permit the drilling process and what rules would govern it.

“Only after this evaluation is completed will a decision be made about whether to permit high-volume hydraulic fracturing in New York,” he said. “Obviously, if there was a public health concern that could not be addressed, we would not proceed.”

The process, also known as hydrofracking, involves pumping vast amounts of water laced with chemicals into underground shale deposits, under high pressure, to release natural gas. Gov. Andrew M. Cuomo has been under pressure to ban the drilling process, or at least to hold off on a decision until more research is done.

Mr. Martens said many of the 80,000 public comments the state had received on hydrofracking during its deliberations focused on the possible harm to public health.

Among the areas of concern are the contamination of drinking-water supplies, air pollution produced by the drilling equipment and the danger of accidents from increased truck traffic.

State legislators, medical societies and health experts have called for a thorough health assessment. Last month, members of major environmental groups met with Mr. Martens to press for an independent review by medical experts before any regulations are made final and drilling is allowed to start.

In his statement on Thursday, however, Mr. Martens rejected the idea of commissioning an outside study, calling it “an inappropriate delegation of a governmental responsibility.”

“To suggest private interests or academic experts bring more independence to the process than government is exactly wrong,” he added. But he also said that Dr. Shah could solicit advice from “the most qualified outside experts” in his review.

Mr. Martens’s statement did not say how long the health study might take, and officials with the environmental department did not return calls.

The state has been studying the possibility of opening up the Marcellus Shale to natural gas drilling since 2008, and released a revised draft report on environmental effects last year. In moving to conduct a separate health review, Mr. Martens said, the state is seeking to prepare “the most legally defensible” environmental report in the event of any litigation that could ensue if the state allows fracking to proceed.

Kate Sinding, a senior attorney with the Natural Resources Defense Council, said her organization would have preferred an independent study. “This is not exactly what we were asking for,” she said. “But if they really solicit the input of truly independent experts as well as hear the concerns of the public, this could provide real value.”

She suggested that the state health review could take a few months or more than a year, depending on how much work the environmental department has already done on studying the potential health effects.

The reaction from the gas industry was resigned. “While we’re extremely disappointed in yet another delay, we have full faith and confidence in the D.E.C.’s analysis and decision,” said Brad Gill, executive director of the industry group the Independent Oil and Gas Association of New York.