WEDNESDAY, April 18 (HealthDay News) -- The U.S. Environmental Protection Agency on Wednesday issued the first national standards to curb air pollution linked with the controversial practice of "fracking."

Fracking refers to hydraulic fracturing, a way to obtain natural gas by forcing fluid into a well to fracture rocks and thus release gas.

Natural gas is being touted by the Obama Administration as a clean energy source and one that does not rely on foreign suppliers.

The standards, to take full effect at the beginning of 2015, "will reduce smog-forming air pollution along with cancer-causing air toxins," contends Gina McCarthy, an assistant administrator for the Office of Air and Radiation at the Environmental Protection Agency (EPA).

"Smog formation has been linked to various health ills including asthma attacks, emergency room visits and premature deaths," she added.

Smog also emits toxins such as benzene that can cause cancer, said McCarthy, who spoke at a Wednesday news conference.

McCarthy estimated that the rule will cut volatile organic compounds (VOCs), which contribute to smog by 190,000 to 290,000 tons a year, and benzene by 12,000 to 15,000 tons a year.

Although the rule does not directly target greenhouse gases, methane levels will also be reduced as a byproduct of technologies required to meet the tougher standard, she said.

Environmentalists have been concerned about natural gas that escapes these wells, filtering up into the air and potentially harming human health.

In a statement released Wednesday, Meleah Geertsma, of the environmental watchdog group National Resources Defense Council, called the EPA move "a critical step toward protecting our kids, our communities and our planet." But Geertsma, an attorney for NRDC's climate and clean air program, also said that the initiative does not go far enough. "The EPA needs to do more to protect people living near oil and gas production facilities," she said.

According to the Associated Press, last year in western Wyoming fracking resulted in ground-level ozone, the main constituent in smog, at levels that were worse than that seen in smog-ridden Los Angeles.

Benzene levels considered dangerous to human health have been detected in Dish, Texas, which is near numerous fracking sites, the AP also reported.

On the other hand, drilling sites in four counties in Pennsylvania have not been associated with air emissions problems, the AP said.

Operators of new "fracked" natural gas wells will have to capture any additional natural gas using technologies that are already available, according to the EPA rules.

They then will be able to sell that extra gas, making the new regulations ultimately cost-effective and even cost-saving, McCarthy said.

Between now and Jan. 1, 2015, natural gas operators must either "flare" (burn) gas emissions or use "green completions" technologies to prevent gas from escaping. Starting in 2015, however, companies will have to use green completions.

"Completion" refers to a process taking place over three to 10 days, as a well transitions from being drilled to actually producing natural gas. Much of the pollution from fracking is thought to be emitted during this period.

The EPA estimates that about 13,000 wells are fractured or re-fractured each year in the United States. Some states, such as Colorado and Wyoming, already regulate the fracking industry, the AP noted.

"This is the first national standard to reduce air pollution from hydraulically fractured wells," McCarthy said. "When implemented, it will require operators to capture gas that would otherwise escape into the air, keeping harmful pollution out of the air."

But the NRDC believes more must be done. In their statement, the group said it is "disappointed that EPA has allowed industry more than two and a half years for full compliance. It should not take that long to build more of the truck-mounted rigs that can capture these gases and put them into the pipelines to be sold at a profit instead of leaked into our air."

The NRDC believes the EPA "also needs to set strong standards that directly curb leakage of methane and other dangerous pollutants from the existing wells and operations."

More information

Find out more about the new standards for fracking at the EPA.