When people talk about natural gas fracking and pollution, they most often are referring to the water issues sometimes associated with the wells.
But a new study suggests that air pollution should be an important part of the conversation also.
“In the development of natural gas, air should also be considered,” Lisa McKenzie, lead author of the study and research associate at the Colorado School of Public Health, said. "People living near the well are potentially at risk for health effects."
The study found potentially dangerous hydrocarbons in the air near wells in western Garfield County, Colorado. They included benzene, which the Centers for Disease Control says can damage the immune system and the Environmental Protection Agency says can cause cancer.
During hydraulic fracturing, or fracking for short, drillers pump large amounts of water mixed with sand and chemicals into the shale formation thousands of feet underground under high pressure. Fracturing the shale around the gas well allows the natural gas to flow freely.
The study looked at the emissions from several hundred wells. There was one ambient measuring station collecting samples for three years near thousands of established wells. There were also samples taken from the well pads of five wells being completed.
“Those samples were where the concentrations of many of the hydrocarbons were significantly statistically higher,” she said.
The report said people living within a half-mile of the wells were subject to five times the EPA’s Hazard Index. The agency is currently considering air pollution standards for natural gas wells and has delayed its decision three times. April 3 is the next due date.
There have been other studies done to measure air pollution, McKenzie said but this one differed in the class of chemicals it studied.
Energy in Depth, an advocate for oil and natural gas, said the study was “unquestionably flawed.”
On its website, the group lists eight problems it has with the study, including “failed to account/control other variables.”
The compounds are released into the air during the drilling process, but some are also associated with the large amounts of diesel trucks and generators that are used by the drillers, McKenzie said.