Much of the debate about hydraulic fracturing has focused on the impact that the controversial method of natural gas extraction could have on water quality in upstate New York.

Some say, though, that air quality is just as big a concern. Last week, an Albany environmental group focused attention on a citizen-driven study in two western states that found elevated levels of harmful chemicals in the air near gas wells and gas-handling facilities.

Based on nine one-time samples collected by residents in Colorado and New Mexico, the study doesn't pretend to be conclusive, but underscores concerns about the impact of gas wells and production facilities on the health of people who live or work near them.

"This gives us a clue there's a serious problem," said Barbara Warren, executive director of the Albany-based Citizens Environmental Coalition, who said proposed state guidelines don't appear robust enough.

New York state environmental officials recently released a revised set of guidelines for natural gas drilling, and anticipate that gas exploration companies could apply for permits to drill 2,000 or more new wells a year in the state.

Modern drilling methods, which involve extensive use of diesel trucks and generators and can lead to atmospheric releases of hydrocarbons and industrial chemicals, have sparked health worries in other states.

Those concerns will be addressed at a public talk this week at the University of Rochester Medical Center. Dr. Bernard D. Goldstein, a professor and former dean of the Graduate School of Public Health at the University of Pittsburgh who has long been involved in air-quality studies, will discuss the public health implications of hydraulic fracturing.

Katrina Korfmacher, a URMC assistant professor of environmental medicine who organized Goldstein's talk, recently visited Garfield County, Colorado, where there are thousands of active natural gas wells and where a health assessment of the industry's impact has been done.

"Here, most of the conversations about impacts have been water-related. There, the most significant issues of concern are about air quality," Korfmacher said.

That same Colorado county that Korfmacher visited was one of the areas where citizen air testing was done under the auspices of California environmental justice group Global Community Monitor. That sampling, conducted near gas wells or gas processing facilities, found elevated levels of several toxic chemicals, including benzene and methylene chloride.

Whether the levels would be sufficient to cause health problems wasn't clear. But the report did cite the case of one Garfield County family living near several drill rigs that had to leave their home after family members experienced headaches and nosebleeds.

Warren said she worried that if a wave of new gas-industry facilities open in New York, unsafe concentrations of such chemicals could taint the air here.

Emily DeSantis, a DEC spokeswoman in Albany, said the agency's proposed gas-drilling guidelines are thorough and rigorous enough that "high-volume hydraulic fracturing can be done with minimal effects to air quality."

Those guidelines, nearly 1,100 pages in length, include about 130 pages dedicated to air quality and air pollution control. DeSantis said the guidelines includes numerous provisions that will minimize air emissions, including tight controls on diesel engines and elimination of open-air impoundments of wastewater, a potential source of chemical vapors.

Warren, however, said she believed the DEC is "still operating in an information vacuum.

"DEC relied on industry submissions and reports for its analysis of regulatory requirements. What we need is a comprehensive assessment of the air quality impacts of these operations based on actual air monitoring data of good quality and sufficient quantity to be able to apply to the industry as a whole," she said.

SORR@DemocratandChronicle.com