Many chemicals used in hydraulic fracturing, or fracking, can disrupt not only the human body’s reproductive hormones but also the glucocorticoid and thyroid hormone receptors, which are necessary to maintain good health, a new study finds. The results were presented Monday at the joint meeting of the International Society of Endocrinology and the Endocrine Society: ICE/ENDO 2014 in Chicago.
“Among the chemicals that the fracking industry has reported using most often, all 24 that we have tested block the activity of one or more important hormone receptors,” said the study’s presenting author, Christopher Kassotis, a PhD student at the University of Missouri, Columbia. “The high levels of hormone disruption by endocrine-disrupting chemicals (EDCs) that we measured, have been associated with many poor health outcomes, such as infertility, cancer and birth defects.”
Hydraulic fracturing is the process of injecting numerous chemicals and millions of gallons of water deep underground under high pressure to fracture hard rock and release trapped natural gas and oil. Kassotis said spills of wastewater could contaminate surface and ground water.
In earlier research, this group found that water samples collected from sites with documented fracking spills in Garfield County, Colorado, had moderate to high levels of EDC activity that mimicked or blocked the effects of the female hormones (estrogens) and the male hormones (androgens) in human cells. However, water in areas away from these gas-drilling sites showed little EDC activity on these two reproductive hormones.
The new study extended the analysis to learn whether high-use fracking chemicals changed other key hormone receptors besides the estrogen and androgen receptors. (Receptors are proteins in cells that the hormone binds to in order to perform its function.) Specifically, the researchers also looked at the receptor for a female reproductive hormone, progesterone, as well as those for glucocorticoid — a hormone important to the immune system, which also plays a role in reproduction and fertility — and for thyroid hormone. The latter hormone helps control metabolism, normal brain development and other functions needed for good health.
Among 24 common fracking chemicals that Kassotis and his colleagues repeatedly tested for EDC activity in human cells, 20 blocked the estrogen receptor, preventing estrogen from binding to the receptor and being able to have its natural biological response, he reported. In addition, 17 chemicals inhibited the androgen receptor, 10 hindered the progesterone receptor, 10 blocked the glucocorticoid receptor and 7 inhibited the thyroid hormone receptor.
Kassotis cautioned that they have not measured these chemicals in local water samples, and it is likely that the high chemical concentrations tested would not show up in drinking water near drilling. However, he said mixtures of these chemicals act together to make their hormone-disrupting effects worse than any one chemical alone, and tested drinking water normally contains mixtures of EDCs.
“We don’t know what the adverse health consequences might be in humans and animals exposed to these chemicals,” Kassotis said, “but infants and children would be most vulnerable because they are smaller, and infants lack the ability to break down these chemicals.”
Fracking & Health: What Does the Evidence Show?
For years, environmentalists, public health officials, and the gas drilling industry have been in a pitched battle over the possible health implications of hydro fracking. But to a great extent, the debate — as well as the emerging lawsuits and the various proposed regulations in numerous states — has been hampered by a shortage of science. Part of the problem is that the fracking industry — through deliberate lobbying efforts — has been relatively successful at blocking research into the health effects of drilling. There are a fair amount of studies on the potential impact of fracking on air and water supplies, but much less research has been done on the long-term health effects for those living near fracking sites.
However, existing evidence does raise significant questions about the potential health risks of fracking. A review of health-related studies published in the journal Environmental Science & Technology concluded that the current scientific literature puts forward “both substantial concerns and major uncertainties to address.”
The potential contamination of drinking water with chemicals used in the fracking process is often cited as the main health concern. While additives make up only 2 percent of the total fluid volume, this can represent 40,000 liters of additives injected per well. An analysis of 353 of these chemicals found that more than 75 percent could have respiratory, gastrointestinal, dermatological, and ocular effects; 40 percent to 50 percent could be neuro-, immuno- and nephrotoxic; 40 percent could be endocrine disruptors, and 25 percent could be carcinogenic.
A recent study from Duke University confirms at least one plausible mechanism for exposure to toxic fracking byproducts in the water supply and adverse health effects related to drilling by demonstrating a significant increase of methane levels in the water supplies of communities near drilling sites.
There is also a growing body of evidence indicating that gas drilling may emit harmful chemicals into the air, which may have significant and deleterious effects on the health of those living near drilling sites.
For example, in one study, performed in Garfield County, Colo., researchers at The Endocrine Disruption Exchange — a non-profit organization that examines the impact of low-level exposure to chemicals on the environment and human health — set up a sampling station close to a well and collected air samples every week for 11 months, from when the gas wells were drilled to after it began production. The samples produced evidence of 57 different chemicals, 45 of which they believe have some potential for affecting human health.
In almost 75 percent of all samples collected, researchers discovered methylene chloride, a toxic solvent that the industry had not previously disclosed as present in drilling operations. The researchers noted that the greatest number of chemicals were detected during the initial drilling phase.
Of the hundreds of chemicals tested in a series of studies by The Endocrine Disruption Exchange, they report that 93% of them affect health and 43% are endocrine disruptors. Endocrine disruptors have been linked to infertility, ADHD, autism, diabetes, thyroid disorders. Even childhood and adult cancers have been found to be linked to fetal exposure to endocrine disruptors. A report issued in March 2012 concludes that endocrine disruptors, even at low doses can have very negative effects on human and animal health.
Notably, the gas drilling industry has sought to limit the disclosure of information about its operations to researchers. They have refused to publicly disclose the chemicals that are used in fracking, won gag orders in legal cases and restricted the ability of scientists to get close to their work sites. In one highly publicized case, a lifelong gag order was imposed on two children who were parties to a legal case that accused one gas company of unsafe fracking operations that caused them to fall sick.
The secrecy of the fracking industry is concerning, particularly given recent findings indicating that chemicals involved in the drilling process could have significant implications for public health. For example, one study, in which researchers at the Colorado School of Public Health collected air samples in Garfield County, Colorado — the site of intensive drilling operations — found the presence of a number of hydrocarbons including benzene, trimethylbenzene and xylene, all of which have been shown to pose health dangers at certain levels. Researchers said that those who lived less than half a mile from a gas well had a higher risk of health issues. The study also found a small increase in cancer risk, which led the researchers to postulate that exposure to benzene was a major contributor to the risk.
Other research has investigated the potential impact of fracking on birth outcomes. For example, Elaine Hill, a graduate student at Cornell University, obtained data on gas wells and births between 2003 and 2010. She then compared birth weights of babies born in areas of Pennsylvania where a well had been permitted but never drilled and areas where wells had been drilled. Hill found that the babies born to mothers within 2.5 kilometers (a little over 1.5 miles) of drilled gas sites were 25 percent more likely to have low birth weight compared to those in non-drilled areas. (Babies are considered as having low birth weight if they are under 2500 grams [5.5 pounds]). Hill’s work is currently under review by a formal scientific journal, a process that could take up to several years.
While the evidence is not yet conclusive, it would certainly be dishonest to state that fracking poses no danger to the public’s health (which, notably, is exactly what the gas drilling industry claims). This is why many lawmakers are pushing for more research into the new technology before more drilling sites are established. From my viewpoint, the most concerning aspect of this debate is that the fracking industry is so invested in preventing scientists from learning more about the potential health effects. This follows a pattern by other industries, such as the cigarette industry, and more recently the gun lobby, to deny very obvious health consequences of using their “product.”
After all, if fracking is so safe — as they claim — why won’t they let us find the evidence to prove it?
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