Fracking: health claims unproven so far [NGW Magazine]
It has now been around a decade since shale development started booming. Concerns over the health impacts of shale drilling have grown alongside production from an ever-increasing number of unconventional wells in the US.
Particular concerns centre on the impact of shale drilling on both air and water quality for those close to wells. Research into such impacts has been underway for several years, but still has some catching up to do, with significant gaps in the knowledge that has been acquired to date.
Correlation, not causation
Various reports of air and water quality issues, as well as related health impacts, have been circulating for almost as long as the US shale industry has been in existence. There have been a handful of high-profile cases, such as that of groundwater contamination in Pavillion, Wyoming, which some linked to hydraulic fracturing activity, though these findings were subsequently disputed.
Meanwhile, others have been studying occurrences of particular illnesses and health issues near shale drilling sites. In a recent example, the Journal of the American College of Cardiology published an article in December 2020, suggesting a possible link between higher rates of hospitalisation for heart failure near areas of unconventional gas development.
But while the science is advancing and the impacts of shale development are now better understood, there is much still to be studied.
“It really took a few years for, I think the medical research community to finally start to do enough work to scratch the surface,” assistant research professor/extension associate at Pennsylvania State University’s (PSU) Marcellus Center for Outreach and Research (MCOR), Dave Yoxtheimer, told NGW. He went on to say that while studies in recent years have shown some correlation between health impacts and proximity to shale wells, questions remained over how strong the correlation is, and such studies had yet to prove causation in any definitive way.
“I think that's been the nut that nobody's really cracked,” he said. “I think there's a lot more research that needs to go into this. There are a lot of question marks,” he added.
“You don't necessarily see widespread impacts of fracking chemicals in drinking water or anything like that, so until you’ve really started to see systemic contamination, it would be really kind of hard to believe that you could see systemic widespread illnesses,” Yoxtheimer continued.
The next step would then be establishing whether there is causation or not, as some potential localised impacts are nonetheless being seen. However, there are a number of obstacles that researchers may struggle to overcome, especially when it comes to data-gathering.
One of the first challenges is that with the shale industry taking off so fast from around 2010-11, there was initially a dearth of baseline monitoring data. Monitoring has subsequently improved and data are tracked more carefully. However, the picture is further complicated by the fact that monitoring requirements vary by state, and that data that are reported to state regulators may not be readily available to researchers looking into various impacts.
“There's a lack of population-level studies, and that's due to one of the biggest difficulties probably – the difficulty in collecting health data,” assistant professor at Syracuse University’s Department of Earth and Environmental Sciences, Tao Wen, told NGW. “A lot of researchers don't have access to those data,” he said.
This problem can be seen across the spectrum of data that make up the health picture for local residents. And it is compounded by the number of wells that are drilled on private land.
“When you're starting to talk about getting somebody's private, residential well groundwater data, it gets kind of sticky. There's a confidentiality aspect to that,” Yoxtheimer said. “But we've been fortunate. We've been working with our state regulators,” he continued. “The energy industry will collect private well samples before drill, so they can see the groundwater quality before drilling to get baseline data. And then, if there's a problem after drilling, they can go back and retest and see if there's any correlation between their operations and contaminants there in private drinking water. But for that data to be out in the public is sensitive. So what we've brokered is a deal with the state regulators where they'll give us that water quality data, and they don't specify exactly which home it came from, but we know what municipality the data came from.”
This approach allows researchers to track any correlations between water quality and drilling activity, and identify potential issues without compromising confidential data. A number of other initiatives are also underway or being planned, with both states and universities further studying the potential impacts of shale activity on air, water and health.
Unsurprisingly, given how much shale gas development is taking place in the relatively populous US Northeast, much of this research is centred on Pennsylvania and surrounding states. A Pennsylvania government spokesman told NGW that the state’s Department of Health was partnering with an academic institution that would design “two observational epidemiological studies focusing on known, or suspected, health effects of hydraulic fracturing.”
The first of these studies will investigate the relationship between fracking and the development of childhood cancers, such as Ewing’s Sarcoma, in Southwestern Pennsylvania. “This will be a case control study and is likely to involve multiple years of [Pennsylvania] cancer registry data, interview of cases and controls, and assessment of possible exposures,” the spokesman said. The second study will be similar to earlier studies on acute conditions, such as asthma and birth outcomes, also using data from Southwestern Pennsylvania. “The study will utilise medical record abstraction, survey design and administration, development of a proxy oil and gas well exposure metric, and statistical analysis,” said the spokesman.
State media subsequently reported that the University of Pittsburgh’s Graduate School of Public Health would receive a $2.5mn contract from the Pennsylvania government to conduct the two studies.
Separately, an assistant professor of informatics at the University of Pennsylvania’s Department of Biostatistics, Epidemiology & Informatics, Mary Boland, told NGW that she was working on linking the ingredients used in fracking fluid to hormonal pathways, including oestrogen and testosterone pathways.
“We believe that linking to the underlying biological mechanisms will enable us to elucidate the health effects and correlate specific chemicals with health toxicity in humans,” she said.
Meanwhile, Syracuse University’s Wen said he was involved in an initiative to use a machine learning approach to predict the occurrence of methane in groundwater. This forms part of a bigger picture where methane contamination from shale development is being studied both for its health and environmental impacts.
“A lot of environmental issues we are studying are actually closely related to health-related problems,” Wen said. “The problems have different time scales, but I would say they are equally important.”
PSU’s Yoxtheimer noted that another area of concern was what comes out of the ground, as well as what goes into it via fracking fluids.
“We're now bringing things up out of the earth that have been down there for hundreds of millions of years,” he said. “And they're natural, but it doesn't mean they're not toxic,” he continued. He identified such waste streams as an area of potential concern over health impacts. “And that's where the challenge is, in safely, managing those waste streams,” he said.
Yoxtheimer noted that health risks go back to exposure pathways – primarily air people breathe and water they drink – and that this waste could present an additional exposure pathway. It is just one of several areas where more research is needed.