A team of researchers at the University of Colorado recently looked at more than 100,000 birth records in the state from 1996 to 2009. They calculated how far each of the mothers lived from an oil or gas well. Lisa McKenzie was the lead author on thestudy.
“What we found was mothers with the most wells around their homes, and closest to their homes, had a 30 percent higher chance of having congenital heart defects than mothers with no wells around their homes,” McKenzie says.
The study found no evidence of increases in another type of birth defect, and even found increased birth weights for babies born to mothers closer to wells.
McKenzie had previously calculated that oil and gas emissions would increase the risk of certain diseases, including cancer, for people living closest to gas wells. She says her calculations in both studies were done with the best available data. But she concedes, there were limitations: she didn’t have information on whether mothers in her birth study had moved during their pregnancy, or detailed information on wells near their home.
“These are both studies that are somewhat preliminary—and they’re what you do to provide justification for doing further study—showing that there is potentially a risk for health effects,” McKenzie says.
Results like the kind McKenzie found with birth defects have raised alarms for environmentalists who use them as ammunition in their fight to slow down the country’s fracking boom. And they fit with stories of some near well sites that fracking has made them sick. In Pennsylvania, 57 people told the state they’ve had health problems they believe were caused by fracking, according to StateImpact Pennsylvania.
But these studies are far from conclusive, and have had a limited effect on setting public policy on drilling.
“The research done to date, I give people enormous credit for it,” says Diana Stares, director of the Center for Energy Policy & Management at Washington & Jefferson College, which reviewed public health research as part of an examination of Marcellus Shale's impact on local communities. “They’ve gone out in many instances, with small amounts of money and really made the best use they possibly could.”
But the scientists can often only examine a small part of the issue, they have limited access to drilling sites, and are sometimes funded by groups that oppose fracking. That makes their research subject to criticism from the gas industry that it’s biased.
Even if their findings show legitimate health concerns, the limitations of their studies mean policymakers are less likely to use them to enact tougher regulations on fracking. Lawmakers “could regard the research as limited and subject to attack and could be unwilling to rely upon it,” says Stares, a former attorney in the Pennsylvania Department of Environmental Protection.
“What really needs to happen is research at a much more sophisticated and extensive level, and it needs to be very objective research, so nobody fights with it,” says Stares. “That’s the problem you have now. The research many public health researchers do gets attacked by the industry as being biased. And vice versa—and so nobody’s willing to accept anybody’s research.”
Stares says a research program funded by a combination of foundation, government, and industry money would go a lot farther in public policy debates.
It’s common for research into fracking’s health risks to be called into question. A case in point is McKenzie’s heart defects study. The oil and gas industry questionedMcKenzie’s objectivity, methods, and conclusions.
The Colorado Department of Public Health and Environment even warned the public against reading too much into the study.
"I would tell pregnant women and mothers who live, or who, at the time of their pregnancy, lived in proximity to a gas well not to rely on this study as an explanation of why one of their children might have had a birth defect. Many factors known to contribute to birth defects were ignored in this study," said the statement, from the department's executive director, Dr. Larry Wolk.
But McKenzie defended her study’s design, even while acknowledging, it isn’t perfect.
"We are not finding causation—this is showing an association, and we need to do more study to verify if there’s causation," McKenzie says.
She is planning a follow-up study to address some of the deficiencies in the study, with funding from the American Heart Association.
“There’s never going to be the absolute study that shows with absolutely no doubt that this causes that,” McKenzie says. “In environmental health, you cannot do a randomized control experiment the way they can with pharmaceuticals.”
Still, she says, there’s a reason why scientists like her are looking at fracking.
“There are chemicals emitted during the process of oil and gas development that are known to be hazardous air pollutants that are associated with very specific health effects,” McKenzie says. “We know that benzene has been emitted, we know that benzene is a carcinogen.”
A study released this week found high levels of toxic chemicals, including benzene and another carcinogen, formaldehyde, in 40 percent of air samples volunteers collected near well sites in six states.
A big stumbling block for filling in the gaps in studies is money. The National Institutes of Health has begun funding some studies—and a new funding source may be coming online soon. The American Petroleum Institute put out a call for proposalsfor scientists to study the public health effects of fracking.