Oil workers monitor a oil pumping and storage site at the Niobrara oil shale formation in Weld County, North eastern Colorado on May 30, 2012. Gas and oil companies are using large amounts of water to obtain shale oil and gas in a process called hydraulic fracturing or fracking. UPI/Gary C. Caskey | License Photo

PHILADELPHIA, April 29 (UPI) -- People living near gas hydraulic fracturing sites are more concerned than had been thought about possible health effects of the drilling, U.S. researchers say.

Dr. Poune Saberi of the Perelman School of Medicine at the University of Pennsylvania and the Center of Excellence in Environmental Toxicology and colleagues collected responses from 72 adults visiting a primary care physician's office in the hydrofracking-heavy area of Bradford County, Pa.


The study participants volunteered to complete an investigator-facilitated survey. Twenty-two percent of the participants said the hydrofracking might be the cause of such health concerns as sinus problems, sleeping difficulties and gastrointestinal problems.

"Almost a quarter of participants consider natural gas operations to be a contributor to their health issues, indicating that there is clearly a concern among residents that should be addressed," Saberi said in a statement.

Within the 22 percent of responders, 13 percent viewed drilling to be the cause of their current health complaints and 9 percent were concerned future health problems can be caused by natural gas operations, said Saberi, the principal investigator.

The previous health complaints by participants were thought to be anecdotal in nature as they were individual cases reported publicly only by popular media, the study said.

"What is significant about this study is that the prevalence of impressions about medical symptoms attributed to natural gas operations had not been previously solicited in Pennsylvania," Saberi said. "This survey indicates that there is a larger group of people with health concerns than originally assumed."

The findings were presented at the American Occupational Health Conference in Orlando, Fla.