Corrected Air Quality Data Near Carroll County Natural Gas Extraction Sites

CINCINNATI--A 2015 Oregon State University study that linked natural-gas fracking in Carroll County, Ohio to increased air pollution and heightened health risks has been corrected by its authors, including a University of Cincinnati scientist. 

The corrected article, released online July 11 in the journal Environmental Science and Technology, still concludes that natural gas extraction contributes polluting chemicals known as polycyclic aromatic hydrocarbons (PAHs) to the air, but in this study, the levels are significantly lower and well below the threshold for unacceptable lifetime cancer risk established by the U.S. Environmental Protection Agency.

The researchers measured levels of airborne PAHs near several Ohio hydraulic-fracturing sites in 2014. PAHs have been linked to increased risk of cancer and respiratory diseases. 

In the original May 2015 article, the researchers reported that PAH pollution from fracking could put a person living in the study area at a 2.9 in 10,000 risk of developing cancer during his or her life. The EPA threshold for unacceptable cancer risk is one in a million. 

The authors retracted the article on June 29, 2016, after discovering an error in a complicated spreadsheet used to calculate the concentrations of various PAH chemicals in the air. 

After redoing the calculations, researchers submitted a corrected version of the article, which finds that the estimated risk for the maximum exposure to fracking-related PAH pollution in the study area is 0.04 in a million—well below the EPA's threshold.

"While errors like this in research are very unfortunate, it is admirable that the Oregon team came forward with the mistake and worked very hard to correct it and publish the results.  These new data demonstrate much lower PAH levels than originally calculated," says Erin Haynes, DrPH, associate professor in the Department of Environmental Health at the UC College of Medicine. "Additional sampling is needed for other potential contaminates including volatile organic compounds, formaldehyde, and particulate matter to ensure a safe environment for community residents."

Haynes explains that the volunteer residents in Carroll County who allowed air sampling on their property have been contacted individually by phone and result letter explaining the new data.  

The study is part of a larger project co-led by Haynes and funded by the National Institute of Environmental Health Sciences. Haynes partnered with Carroll Concerned Citizens and community residents to identify locations for the air sample collections, and worked with the Oregon State researchers on the data collections during a three-week period in February 2014.  Researchers at Oregon State conducted all data calculations.  

Carroll County sits on top of the Utica formation, a deep oil- and gas-rich reef of subterranean shale. The rural county is an active area of natural gas prospecting, with more than one active site per square mile. 

The study got its start when a group of Carroll County citizens approached Haynes, wanting to know more about potential health risks from natural gas extraction.

The prominent health concerns were cancer and respiratory distress associated with exposure to PAHs and volatile organic compounds (VOCs). 

The next phase of the study is currently underway with select residents wearing wristband sensors that collect data on air quality. The wristbands also passively collected PAHs. The Oregon State team is currently analyzing the samples and data are expected by summer 2017.  

The article's coauthors include Oregon State University researchers Kim Anderson, PhD, and Blair Paulik (College of Agricultural Sciences) and Laurel Kincl, PhD, (College of Public Health and Human Sciences).