Deep Impact: Fracking and EDCs

Hydraulic fracturing — or fracking — uses hundreds of chemicals, many of which are known to have adverse effects on the endocrine system. However, further research is needed to determine whether this process is to blame for health issues for residents near these sites.

Garfield County sits in the northwestern quadrant of Colorado, a vast swath of picturesque land that attracts outdoor adventurers and serenity seekers alike. But Garfield County has also become very attractive to those who engage in hydraulic fracturing — fracking — a process that forces sand, millions of gallons of water, and a mixture of chemicals into the earth to extract natural gas and oil from shale. These operations have recently come under closer scrutiny after residents in drilling regions, environmental advocates, and medical investigators expressed concerns about the effects these chemicals have on the air they breathe and the water they drink. Some endocrinologists are especially concerned, since the process involves more than 750 chemicals, many of which are known to disrupt hormone function.

Investigators at the University of Missouri, led by Susan C. Nagel, PhD, and Christopher Kassotis, a doctoral candidate, chose Garfield County, Colo. — an area with more than 10,000 active natural gas wells and a history of accidents and spills — to test fracking’s effects on endocrine disrupting activity in water. They hypothesized that the surface and ground water and a selected subset of chemicals used in natural gas drilling operations there would exhibit endocrine-disrupting activities, namely on estrogen and androgen receptors. “We wanted to think about the worst case scenario to test this idea that drilling might be contaminating surface and/or ground water,” Nagel says.

Some residents may already be experiencing the worst case scenario. “For that first study,” Nagel says, “it was not hard to find people who wanted us to come and sample.”

One of the individuals they talked to, whose property was near a fracking accident site, had a “very severe” contamination of his drinking water, which flowed into a pond at his hunting operation on a plateau. “He came up there in the spring to open up the operation,” Nagel says. “He had a tradition of every time he drove up there from his house down below he’d throw a stick out into the pond, and his dog would go out and get it.”

The dog died a couple of months after the incident that polluted the pond, and the man himself experienced “a lot of short- and long-term health problems” because he drank from the spring that feeds the pond, before realizing it had been contaminated. “Actually, in addition to endocrine-disrupting activity, the pond was the most toxic of any of our samples in that study,” Nagel says. “They have since settled with one of the oil and gas companies.

“Folks by and large felt like their health was being compromised,” she continues, “[as well as] their pets’ or livestock’s [health].”

Worthwhile Investigation

Fracking is a very hotly contested issue in the United States. Proponents of the process have pointed to fracking as a boon for local communities, providing jobs and tax revenue, and being partially responsible for the recent dip in gas prices. Fracking is being closely watched as researchers also recognize more and more how the environment influences health and development.

But even the National Institute of Environmental Health Sciences cannot take an official position on fracking, saying that “the short answer is [they] don’t know” whether fracking poses health risks to the people living near drilling sites, since the science is still ongoing and nothing has been proven conclusively. For instance, according to a 2014 paper published in Environmental Health Perspectives, in 2009 the U.S. Environmental Protection Agency found evidence that groundwater in Pavillion, Wy., was contaminated with benzene, xylenes, gasoline range organics, diesel range organics, and total volatile hydrocarbons in shallow wells above 169 gas-producing fracking sites. The authors, led by Trevor M. Penning, PhD, of the University of Pennsylvania, wrote that the pollution was attributed to 33 nearby surface pits used to store drilling waste water, but since there had been no baseline water quality measurements before the drilling started, it could not be determined for certain whether fracking had caused the pollution.

So harmful chemicals are found in the fracking process, and the people who live near drilling sites may experience health problems, but correlation does not equal causation, and it’s impossible to test on human subjects, for obvious reasons. It’s a worthwhile investigation, though, because the impacts on the public health could be huge.

“Very Troubling” Findings

The University of Missouri team initially chose five different accident or spill sites to test in Garfield County, rural areas with well water, sparsely populated scenic strips of land — an area called the Grand Valley where mountains rise on either side of the Colorado River. The first site they hiked down to was a property adjacent to a drilling site (fracking had gone on under this property), with a creek where bubbles had started appearing a few years prior. The researchers collected samples from the surface water of the creek there and from the two monitoring wells that had been installed after the bubble incident.

“These were sites that had very dense drilling around them (40–130 plus wells within one mile) and that had experienced some sort of spill of the fracking fluids over the last few years at the site,” Kassotis says. “We then collected samples from within the same shale region but outside the drilling area, and also some here in Missouri.”

“While some may argue that the chemicals are diluted, endocrinologists are aware that even very low dose exposures to endocrine-disrupting chemicals can have effects in the bodies of exposed individuals. Furthermore, without knowing much about the nature of these chemicals, it is possible that some are long-lived and may remain in the environment for long periods of time.”

— Andrea Gore, PhD, University of Texas; editor-in-chief, Endocrinology

For the first study, the team analyzed 12 suspected or known endocrine-disrupting chemicals (EDCs) used in fracking operations to determine just how much these chemicals affected the body’s reproductive hormones. They found that the water samples collected from the drilling sites exhibited higher levels of EDC (estrogenic, anti-estrogenic, and anti-androgenic) activity than the samples from the control sites in the drilling-sparse areas of Garfield County and Boone County, Mo., and published their results in the March 2014 issue of Endocrinology.

“The strongest case here is that samples taken outside the drilling-dense region that had not experienced spills did not exhibit the activity seen at our oil/gas sites,” Kassotis says. “As we expect that other hormonal contributors to water within a region are relatively similar, that is compelling evidence that we may be seeing activity due to the spills. This is further substantiated in that we absolutely biased our sampling in this initial work. These were sites that we knew had spills that had impacted water. So we do suspect that the activity was likely due to fracking operations.”

“This finding was very troubling,” says Andrea Gore, PhD, of the University of Texas, and editor-in-chief of Endocrinology, “because the fracking process uses large volumes of water, and mixing chemicals into the water can contaminate the watershed. While some may argue that the chemicals are diluted, endocrinologists are aware that even very low dose exposures to endocrine-disrupting chemicals can have effects in the bodies of exposed individuals. Furthermore, without knowing much about the nature of these chemicals, it is possible that some are long-lived and may remain in the environment for long periods of time.”

Nagel, Kassotis, and their team were careful with their interpretation of the data and made no claims linking the drilling operations to EDC activity. “We cannot say [the observed EDC activity was due to fracking] conclusively until we have done effect-directed analysis work on those samples,” Kassotis says. “That is, combining our bioassays in the lab with the work of an analytical chemist to determine exactly which chemicals are contributing to the activity that we observe.”

Adverse Effects

And yet, the evidence of adverse health effects experienced by the residents of these drilling-dense areas in the U.S. is hard to ignore. A study published in Environmental Health Perspectives led by Peter M. Rabinowitz, MD, MPH, of Yale University School of Medicine, found that the number of reported health problems was greater in residents living closer to natural gas wells in Pennsylvania than those further away, with skin conditions and upper respiratory symptoms reported most frequently. The interesting thing is that fracking was never mentioned to the participants, only later correlated to distance from the nearest site.

Another study published in Environmental Health Perspectives led by Lisa M. McKenzie, of the Colorado School of Public Health in Aurora, found an increased risk of congenital heart defects and neural tube defects in children born to mothers living near natural gas wells during pregnancy. However, the researchers could not determine causation, as they did not have blood levels of these chemicals, though it was controlled for confounders.

The question remains whether these people experience more adverse health outcomes than those in similar regions without fracking, Kassotis says. “There have been anecdotal reports about adverse health effects that span the spectrum — endocrine/fertility, nausea, dizziness, tremors, headaches, nosebleeds, negative birth outcomes, respiratory issues, etc. The controlled work to really see whether these are greater near these operations though, is largely lacking,” he says.

Digging Deeper

After that initial study, the University of Missouri researchers extended their analysis to determine whether the fracking chemicals affected other key hormone receptors besides estrogen and androgen receptors. They repeatedly tested 24 chemicals for EDC activity in human cells and found that 23 of those 24 chemicals block the activity of one or more important hormone receptors, not just androgen and estrogen receptors but glucocorticoid, progesterone, and thyroid hormone receptors as well.

But again, the presence of these chemicals in the samples doesn’t prove causation, as Kassotis pointed out when presenting these results at ICE/ENDO 2014 in Chicago. EDCs are contributed to water from a large number of sources — aquatic organisms that excrete or release hormones, livestock, pharmaceuticals that enter the water after not being removed in wastewater treatment plants, agricultural pesticides run-off, and waste from urban, industrial, and medical areas.

The University of Missouri team’s current work has now extended their previous studies to in vitro and in vivo analyses of the mixtures of chemicals they had previously evaluated — testing several mixtures in estrogen, androgen, thyroid, progesterone, and glucocorticoid receptor reporter gene assays in human breast cancer cells, which they say “has provided evidence of additive antagonist activity for several of these mixtures.” The team is also wrapping up its first large mouse experiment, exposing mice during gestation to a laboratory-created mixture of 23 of the aforementioned chemicals, writing that the “completion of these studies should substantially increase our knowledge of consequences of prenatal exposure to a complex mixture of hydraulic fracturing chemicals and of potential health risks associated with this process.”

They will then move forward with more animal work, as well as more comprehensive water sampling in Garfield County and other drilling regions across the country. The researchers also intend to do effect-directed analysis work with their chemist, Chung-Ho Lin, PhD, moving forward to determine which chemicals are contributing to the observed activity. “Coming out of this I expect we will be in a much better position to judge whether drilling operations are the source of the activity we saw previously,” Kassotis says.

Nagel says that they have mapped out more experiments to take place over the next few years, including trying to pinpoint exactly which chemicals are used that may be causing the endocrine-disrupting activity, expanding the types of endocrine-disrupting activity they’re analyzing, and looking at animal endpoints, with both adult and developmental exposures.

“Once we work through all of this data, we may be able to target specific organs or endpoints going forward to look at in greater detail,” Kassotis says. “For instance, decreased sperm counts in males or decreased follicle counts in females (or altered testes/ovary weights) might suggest impaired fertility. We could absolutely then examine fertility in the animals in a more comprehensive way and work out exactly what is going on.”

The Role of Research

Late last year, New York’s acting commissioner of health, Howard A. Zucker, MD, JD, wrote a letter to Joseph Martens, the commissioner of the New York State Department of Environmental Conservation, describing the need to consider the science regarding High Volume Hydraulic Fracturing (HVHF) and public health risks. Zucker writes that New York’s Department of Health recommends that fracking not proceed in New York until the science provides more conclusive evidence to determine what level of risk to the public health fracking carries.

“So when the industry makes a statement saying that the underground injection [fracking] of these fluids has not been linked to cases of water contamination, they are sidestepping the numerous surface spills of these fluids and the other routes of contamination present throughout the cradle to grave process. The same goes for health statements.”

Christopher Kassotis, PhD, University of Missouri, Columbia, Mo. 

This is still all very new, and Nagel says these are questions that are “just now being asked.” For the time being, fracking remains a polarizing issue. New York banned fracking after a Public Health Review, and researchers are continuing work on exploring fracking’s effects on human health. But parties interested in these operations continue to produce and air advertisements touting fracking’s safety. And while that may turn out to be true, it’s not the whole story. “Fracking is only one part of the entire process, and chemicals are added throughout the entire drilling and production processes,” Kassotis says. “So when the industry makes a statement saying that the underground injection [fracking] of these fluids has not been linked to cases of water contamination, they are sidestepping the numerous surface spills of these fluids and the other routes of contamination present throughout the cradle to grave process. The same goes for health statements.”

Indeed, the researchers don’t necessarily want to end natural gas drilling; they just want to make certain that drillers are going about it as intelligently as possible. During the Missouri team’s most recent trip, while meeting with landowners to coordinate sampling efforts, Kassotis says, one of the residents made the comment that they felt it was important to say they were not so-called “fracktivists”.

“They were just interested in having clear information on potential health risks, chemicals used, and greater overall transparency from industry,” he continues. “In a way, that’s how I view the role of research — to help fill those gaps, inform the public, and to help industry adjust methods, when necessary, to achieve as safe a process [or product] as possible.”

— Bagley is the associate editor of Endocrine News. He wrote about radio personality Froggy and his mission to get the word out about acromegaly in the February issue.

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