CORVALLIS, Ore., May 13 (UPI) -- Update July 7, 2016: The study "Impact of natural gas extraction on PAH levels in ambient air" by L. Blair Paulik et al., originally published in the journal Environmental Science & Technology on March 26, 2015, was retracted by the authors on June 29, 2016.
The authors report the original article contains incorrect PAH air concentrations due to a calculation error that "resulted from using incorrect units of the ideal gas constant, and improper cell linkages in the spreadsheet used to adjust air concentrations for sampling temperature."
Correcting the error "significantly" changes PAH concentrations and "changes some of the conclusions reported in the original article."
Original story follows:
The explosion of hydraulic fracturing, or fracking, in the oil and natural gas industry as a method of extracting fuels from shale basins has raised dozens of environmental concerns including increased risk of air pollution and respiratory issues among them.
A new study found that contaminants in the air from fracking exceed levels deemed safe by the Environmental Protection Agency and may pose health risks to those exposed.
The study, conducted by researchers from Oregon State University, was conducted in Carroll County, Ohio, the busiest county for fracking in the state with 354 horizontal wells spread throughout its 399 square-miles.
Fracking causes polycyclic aromatic hydrocarbons (PAHs) to be released as a byproduct of the process. Some of these are linked to cancer and respiratory ailments.
"Air pollution from fracking operations may pose an under-recognized health hazard to people living near them," Kim Anderson, an environmental chemist with OSU's College of Agricultural Sciences, said in a press release.
Researchers placed passive air samplers near 23 properties up to 3 miles from natural gas wells, testing for 62 PAHs over the course of three weeks. The samplers detected 32 PAHs, with levels decreasing further away from wells.
Samples showed that those living or working closest to wells would be at 30 percent higher risk than those a mile or more away. The data showed, however, that anybody in the study area, based on calculations using the EPA's worst case scenario of exposure 24 hours a day for 25 years would be exposed at to a risk higher than what the agency says is acceptable.
"Actual risk would depend heavily on exposure time, exposure frequency and proximity to a natural gas well," Anderson said. "We made these calculations to put our findings in context with other, similar risk assessments and to compare the levels we found with the EPA's acceptable risk level."
The study was published in the journal Environmental Science & Technology.