Fracking may worsen asthma for nearby residents, study says

People who live near heavy fracking might be more prone to asthma attacks than those who live farther away, according to results of a study based in the Marcellus shale region.

A review of 36,000 patients' medical records from 2005 through 2012 showed that people living closer to bigger or more active wells were up to four times more likely to seek treatment for asthma than those living farther away, according to the study results, published Monday by JAMA Internal Medicine.

The study found an association between fracking and asthma attacks but did not prove fracking caused the episodes. There's also no way to tell from the study whether asthma patients exposed to fracking fare worse than those exposed to more traditional gas drilling methods or to other industrial activities.

“It makes us think that there could be health effects of unconventional natural gas development,” said Sara Rasmussen, the study's lead author and a Ph.D. candidate at John Hopkins Bloomberg School of Public Health in the Department of Environmental Health Sciences.

Fracking, or hydraulic fracturing, breaks apart rock thousands of feet below the water table to harvest gas and oil. It is a relatively new method of extraction, and few large studies have assessed its health impacts.

Rasmussen said air pollution and stress from fracking should be more closely studied to see if the activity causes asthma attacks.

“We appreciate that the authors acknowledge that their dataset and methodology prove absolutely nothing scientifically beyond their desire for additional research,” said Erica Clayton Wright, a spokeswoman for the Marcellus Shale Coalition, a gas industry trade group.

The group also questioned why the authors didn't compare their data to trends before fracking started in 2005. More than 6,200 wells have been drilled in the state since then, according to the study.

The study's authors analyzed data from asthma patients aged 5 to 90 who were treated at Geisinger Clinic, a health system that treats more than 400,000 Pennsylvanians. The study incorporated variables, including distance from wells, how many there were near an asthma patient's residence and how big the wells were. Asthma patients in the study were broken into groups based on their fracking exposure, and the authors found that those exposed to the heaviest activity levels sought treatment more often than those with lower activity levels. Treatment included hospitalization, emergency room visits and filling of prescriptions for asthma medication.

The authors adjusted their findings to account for asthma risk factors such as family history, poor health, race and socioeconomic factors, according to the results. They also accounted for increased seasonal asthma risks that come from pollen, Rasmussen said.

Dr. Deborah Gentile, director of allergy and asthma research at Allegheny Health Network, said the results are not surprising.

“We know that fracking may result in air pollution — some related to volatile organic compounds coming out of the wells and some related to the truck traffic into and out of drilling sites,” Gentile said. “It's pollution, right there next to where people are living.”

Gentile said she expects gas and oil industry experts to dismiss the study. She said the next step is to delve into cause and effect.

“The industry will continue to point out the jobs they are creating,” she said. “We're not against people having jobs, obviously, but we want them to be aware of these problems.”

Tim Dugan, chief operating officer at Cecil-based Consol Energy, said he had not seen the study and couldn't directly address it. He said several similar studies done by prominent universities were later found to contain “faulty data.”

“The impact from hydraulic fracturing, the impact from drilling, is much less significant than it was initially claimed to be,” Dugan said.

Albert Presto, a research professor at Carnegie Mellon University's department of mechanical engineering who studies air pollution, said the study appears to be detailed.

“A lot of these wells are located in overwhelmingly rural areas and the population density is low,” he said. “It appears that proximity to the well has a lot to do with asthma exposure. What they are concluding is that there needs to be an even more detailed assessment, and I agree with that.”

Venteicher and Schmitt are Tribune-Review staff writers. Reach Venteicher at 412-380-5676 or wventeicher@tribweb.com. Reach Schmitt at 412-320-7991 or bschmitt@tribweb.com. The Associated Press and staff writer Michael Walton contributed.