1. An Exploratory Study of Air Quality near Natural Gas Operations. Human and Ecological Risk Assessment, 2012.
The study, performed in Garfield County, Colo., between July 2010 and October 2011, was done by 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.
In the study, researchers 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 they began production. The samples produced evidence of 57 chemicals, 45 of which they believe have some potential for affecting human health.
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In almost 75 percent of samples collected, researchers discovered methylene chloride, a toxic solvent that the industry had not disclosed as present in drilling operations. The researchers noted that the greatest number of chemicals were detected during the initial drilling phase.
While this study catalogued the chemicals found in air emissions from gas-drilling operations, it did not address exposure levels and their potential effects. The levels found did not exceed safety standards, but there has been much debate about whether standards adequately address health threats to women, children and the elderly.
The researchers admitted their work was compromised by their lack of full access to the drilling sites. The air samples were collected from a station close to what is known as the well pad but not the pad itself.
The gas drilling industry has sought to limit the disclosure of information about its operations to researchers. It has 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 work sites. In a highly publicized case last year, 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.
In 2009, the Independent Petroleum Association of America started Energy In Depth, a blog that confronts activists who are fighting to ban fracking and challenges research that in any way depicts fracking as unsafe.
Energy In Depth responded to this Garfield County study and criticized its lack of proper methodology. The blog post also questioned the objectivity of the researchers, asserting that their “minds were already made up.”
The industry has also been performing its own array of studies.
Last year, for instance, an industry-funded study on the methane emissions from fracking wells was published in the prestigious journal, Proceedings of the National Academy of Sciences. It concluded that only very modest amounts of methane – a contributor to climate change — were being emitted into the air during fracking operations.
The study came under heavy criticism from Cornell University researcher Robert Howarth, who two years before had published work that claimed methane emissions from shale gas operations were far more significant.
“This study is based only on evaluation of sites and times chosen by industry,” he said.
2. Birth Outcomes and Natural Gas Development. Environmental Health Perspectives, 2014.
The study examined babies born from 1996 to 2009 in rural Colorado, a state that has been a center of fracking for more than a decade. It was done by the Colorado School of Public Health and Brown University.
The study asserted that women who lived close to gas wells were more likely to have children born with defects such as oral clefts and heart issues. For instance, it claimed that babies born to mothers who lived in areas dense with gas wells were 30 percent more likely to have congenital heart defects.
The researchers, however, were unable to include data on maternal health, prenatal care, genetics and a host of other factors that have been shown to increase the risk of birth defects; that information was not publicly available. A common criticism of many scientific studies is that they do not fully analyze the possibility of other contributing factors.
The study has thus come under attack from both the industry and state public health officials. Dr. Larry Wolk, the state’s chief medical officer, said “people should not rush to judgment” as “many factors known to contribute to birth defects were ignored” in the study.
But Lisa McKenzie, one of the lead authors of the study, said there was value to the work.
“What I think this is telling us is that we need to do more research to tease out what is happening and to see if these early studies hold up when we do more rigorous research,” she said.
In Pennsylvania, 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 21Ž2 kilometers (a little more than 11Ž2 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 2,500 grams (51Ž2 pounds).
Hill’s work is under review by a formal scientific journal, a process that could take three or four years.