The Environmental Protection Agency estimates that between 25,000-30,000 new oil and gas wells were drilled and hydraulically fractured annually in the U.S. between 2011 and 2014.
A feature article in the journal Health Affairs says the body of research on the potential health effects of all this fracking is "slim and inconclusive."
David Tuller wrote the article.
He’s the academic coordinator of the University of California-Berkeley's joint masters program in journalism and public health.
Tuller says there are gaps in what we know about potential health effects from fracking, and he says those gaps often go un-addressed.
“One thing is that you can’t do what we call 'experimental studies,' so you can’t study compounds in people,” he says.
Instead, he says researchers make associations between, for example, a set of health data in a region and the region’s fracking wells.
“It’s very hard to prove causal effects from that – that one thing caused another,” he says. “So that’s one problem. Another problem is that many of the chemicals that are used are proprietary and the mixtures of chemicals that are used are proprietary, so there’s a lot of data that the companies hold that they don’t have to disclose.”
He says government studies, then, often must be done without some data held by companies. Tuller says the government can only force companies to disclose certain types of information.
Prospective studies – studies completed over time in a specific area – are also largely missing from what we know about potential health effects from fracking, Tuller says. So, for example, a researcher could run tests on a water well before fracking starts, and then continue to take samples over time to see if there was any contamination of the well.
“That’s truly the way you can sort of prove causal effects in this kind of situation,” he says. “Again, that’s made very, very difficult by a lack of big data sets and by again, the companies’ often unwillingness to share basic data and to participate in those studies.”
The EPA's drinking water assessment
The EPA just released its draft report on the effects of fracking for oil and gas on drinking water and it pointed out some instances where fracking operations did contaminate water supplies. But the assessment also noted that the EPA could not find evidence that fracking has led to widespread, systemic contamination of drinking water so far.
“I think it’s a political question," Tuller says. "Do you want to wait until there are widespread, systemic impacts on drinking water resources before you can take any action? You know, that’s a question that the politicians have to answer and that’s a question that people have to ask themselves, what kind of environmental regulation they want."
He also says the EPA acknowledges in its assessment that it has “many, many limitations.” These limitations range from a shortage of prospective studies to the inaccessibility of some information on hydraulic fracturing activities and potential impacts.
For more on the EPA's draft assessment, you can read this Inside Climate News article.
Can these information gaps be filled?
Tuller talked to public health professionals about ways to fill in the gaps and strengthen the body of research on health effects from fracking.
He found that many roadblocks prevent progress.
“Well I think, you know, it takes a lot of money,” he says.
Lately, however, he says funding has been scarce, especially for the kind of long-term studies where scientists could monitor wells before and after fracking begins.
“One of the things that’s happened with this area is that you’ve had so much well development so quickly, and so, already there’s a whole body of data that you’re not going to get because you didn’t do baseline studies before it all happened.”