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Fracking, shale gas and cancer: Health risks at every step

By Barb Harris

“We’ve got to push the pause button, and maybe we’ve got to push the stop button” on fracking, said Dr. Adam Law, an endocrinologist at Weill Cornell Medical College in New York. Law was among doctors at a conference in Virginia calling for a moratorium on hydraulic fracturing for natural gas in populated areas until health effects are better understood. The January 2012 conference was organized by the Mid-Atlantic Center for Children’s Health and the Environment and Physicians, Scientists and Engineers for Healthy Energy.

Fracking for shale gas has been the hot environmental health story of 2011. An unfamiliar word to most people a year ago, fracking is now a household term in much of North America. Millions of people already live with the effects of shale gas and fracking, or face the impending threat. Fracking is a technology used to extract natural gas from dense shale, (or from coal). Fracking for shale gas combines several new techniques, including multi-well pads, horizontal drilling, high pressure fracturing, and the addition of fracking fluids containing toxic chemicals to huge volumes of fresh water.

Development of shale gas, including fracking, releases toxic chemicals into air, water and soil at every step of the process, from drilling to waste storage and disposal. Multiply these exposures by thousands, because shale gas development is dense, averaging one well pad with 8 or more wells per 10 acres. In Pennsylvania, more than 3,000 gas fracking wells and permitted well sites are located within two miles of 320 day care centers, 67 schools and nine hospitals, and development is still in the early stages.

Over the last year, the public health impacts of fracking have gained increasing attention. Scientific American, June 2011, published an article titled “Science Lags as Health Problems Emerge Near Natural Gas Fields.” “In some communities it has been a disaster,” states Christopher Portier, director of the U.S. Agency for Toxic Substances and Disease Registry (ATSDR) and the National Center for Environmental Health. “…We do not have enough information on hand to be able to draw good solid conclusions about whether this is a public health risk as a whole.” In July 2011, Global Community Monitor released “Gassed”, a study of toxic air near natural gas operations in Colorado and New Mexico. When citizens became ill in large numbers and could not convince government agencies to respond to their concerns, they were trained by Global Community Monitor to take their own air samples. The samples were sent to a lab for analysis, and the results compiled. Citizen air sampling found four known carcinogens, including high levels of benzene and acrylonitrile, as well as toxins known to damage the nervous system and respiratory irritants.

Corporate pressure to develop shale gas is intense and poses the same risks to Canadians as Americans are already facing. New Brunswick and Nova Scotia have been hotbeds of Canadian resistance to shale gas and hydraulic fracturing this year. Thousands of people have educated themselves and their neighbours, demonstrated in the streets, written letters, and held community meetings.

In British Columbia and Alberta where fracking for shale gas and coal bed methane have taken place for over a decade, the actual health impacts, as well as evidence that health risks have never been appropriately assessed, are slowly coming to light. In Ontario, shale gas development has not yet started, but oil and gas companies have quietly leased huge tracts of land in preparation. Québec remains the only province to enact, and continue, a moratorium on shale gas development and fracking. That moratorium too is under threat, in spite of tremendous public opposition to fracking through public hearings and grassroots actions.

Fracking and shale gas pose serious and irreversible multiple health risks, including cancer, respiratory damage and endocrine disruption that can lead to birth defects and increase cancer risks. It is too early yet to know definitively whether cancer rates are rising in areas where shale gas development and fracking is taking place. But there is abundant evidence of exposure to carcinogenic substances from these operations.

Environmental biologist and prize-winning author Dr. Sandra Steingraber (photo below) summarizes the cancer risks of fracking in a letter to New York State Governor Cuomo. New York State is poised to decide whether to lift a moratorium on fracking and allow extensive development throughout the state. The state’s environmental assessment has been widely criticized for virtually ignoring all health issues. The Steingraber letter was signed by major cancer prevention organizations throughout New York State and sent to Governor Cuomo and review panel members on December 12, 2011 as part of the state’s environmental review process.

The main points of the letter are excerpted below. Numbering was inserted by An Ounce.

1. Hydraulic fracturing introduces cancer risks from the start and into perpetuity. Cancer-causing chemicals are associated with all stages of the high-volume hydraulic fracturing process, from the production and use of fracking fluids, to the release of radioactive and other naturally hazardous materials from the shale, to transportation and drilling-related air pollution, to the disposal of contaminated wastewater. The potential for accidents during the injection and transportation of fracking chemicals concerns us deeply. And, as data from other states clearly demonstrate, the storage, treatment and disposal of the contaminated water can be a source of human exposure to chemical carcinogens and their precursors (Volz, 2011). In addition, the industrialization of the landscape and congestion of small communities with truck traffic impairs the safety and healthfulness of outdoor exercise. Regular exercise is an important, established risk reducer for many cancers, including breast cancer (Bernstein, 2009). Outdoor exercise is associated with a greater intent to continue the activity, along with other positive health indicators.

2. Fracking fluids contain carcinogens and cancer-promoting chemicals. More than 25% of the chemicals used in natural gas operations have been demonstrated to cause cancer or mutations (Colborn, Kwiatkowski, Schultz, & Bachran, 2011). Between 2005 and 2009, according to the Committee on Energy and Commerce, hydraulic fracturing companies used 95 products containing 13 different known and suspected carcinogens. These include naphthalene, benzene, and acrylamide (Committee Staff for Waxman, 2011). Thirty-seven percent of chemicals in fracking fluids have been identified as endocrine-disruptors. By definition, these substances have the power, at minute concentrations, to alter hormonal signaling pathways within the body. Many can place cells on the pathway to tumor formation. Exposure to endocrine-disrupting chemicals has been implicated in cancers of the breast, prostate, pituitary, testicle, and ovary (Birnbaum & Fenton, 2003; Soto & Sonnenschein, 2010). These exposures may alter gene expression in pregnancy and early life (Colborn, et al., 2011).

3. Fracking operations release from the earth radioactive substances, carcinogenic vapors, and toxic metals. The shale bedrock of New York State contains many highly carcinogenic substances that can be mobilized by drilling and fracturing. Among these are arsenic, chromium, benzene, uranium, radon, and radium (Bishop, 2011). Drill cuttings and flowback waste are typically contaminated with naturally occurring radioactive substances and cancer-causing metals, which would otherwise remain safely entombed underground. Flowback waste can contain up to 16,000 picoCuries per liter of radium-226, this is more than 200 times higher than the discharge limit in effluent (60 pCi/L) and more than 3,000 times higher than the US EPA drinking water standard (5 pCi/L) (NYSDOH Bureau of Environmental Radiation Protection, 2009). Traditional water filtration cannot remove these contaminants. We are especially alarmed by the ongoing practice of burying radioactive drill cuttings on-site (Bishop, 2011) and of using radioactive production brine from (currently out-of-state) fracking operations on New York State roads, for purposes of dust control and de-icing (NYSDOH Bureau of Environmental Radiation Protection, 2009). This practice exposes unknown numbers of people, without their consent, to unknown amounts of a known human carcinogen.

4. Fracking pollutes the air with known and suspected human carcinogens. Air pollutants from fracking take the form of diesel exhaust (from trucks, pumps, condensers, earthmoving machines, and other heavy equipment) along with volatile organic compounds, including benzene (released from the wellheads themselves) and formaldehyde (produced by compressor station engines). Exposure to these air pollutants have been demonstrably linked to lung, breast, and bladder cancers (Brody et al., 2007; Liu et al., 2009). Using US EPA risk assessment tools to examine carcinogenic effects of air quality at oil and gas sites, researchers in Colorado found excess cancer risks from air pollution alone (from 5 to 58 additional cancers per million). At 86 percent of these sites, the human carcinogen benzene was found at hazardous levels. Airborne concentrations of other carcinogens were also elevated (Witter et al., 2008).

Volatile organic compounds can combine with tailpipe emissions to create ground-level ozone. We are alarmed by studies conducted in the gas fields of Wyoming that reveal ozone non-attainment in areas with formerly pristine air quality (Wyoming Department of Environmental Quality, 2009). Ozone can travel up to 200 miles beyond the gas production area (Colborn, et al., 2011). While not a direct carcinogen, ozone exposure is strongly associated with premature death and is believed to promote the development of metastases, thus making cancer more lethal (Breslin, 1995; Fann et al., 2011). Exposure to traffic exhaust and petroleum fumes further potentiates tumor formation and increases cancer risk (Hanas et al., 2010).

Natural gas drilling in New York State is predicted to increase heavy truck traffic on local roads by as much as 1.5 million more trips per year, with an average of 90 and up to 1000 trucks per day at a single well pad (NYSDOT, 2011). For each individual site, hundreds of tanker trucks hauling fracking fluids for injection and flowback fluids for disposal will roll through our communities and neighborhoods, and yet no one has calculated the cumulative impact of the resulting particulate matter and ozone on public health.

We remind the Governor that traffic exhaust, especially from diesel engines, is a well-established cause of chronic illness and premature death – even at levels well below regulatory limits. Most ominously, research is steadily corroborating the relationship between childhood leukemia and traffic density, and childhood leukemia and exposure to airborne benzene (Amigou et al., 2011; Pearson, Wachtel, & Ebi, 2000; Whitworth, Symanski, & Coker, 2008). We are also deeply concerned by the growing evidence linking lung cancer in non-smokers to air pollution, including traffic exhaust. Among adults, non-smoker’s lung cancer is now the sixth most common cancer diagnosis, and rates are rising particularly rapidly among women. A new, nationwide study finds that people who have never smoked but live in areas with higher air pollution are 20 percent more likely to die from lung cancer than people breathing cleaner air (Turner et al., 2011). Fracking will increase this lethal risk.

5. Fracking adds carcinogens to drinking water. Nationwide, more than a thousand different cases of water contamination have been documented near fracking sites. We draw your attention to one of these: the drinking water wells of Pavillion, Wyoming. An EPA study released just this month confirms the presence of the carcinogen 2-butoxyethanol, a widely used fracking chemical, in the aquifer under Pavillion, which is an intensively drilled community (U.S. Environmental Protection Agency, 2011). Pavillion’s drinking water also contains benzene, naphthalene, and diesel fuel. We are deeply troubled that confirmation of these cancer-causing contaminants comes three years after their initial discovery and in the wake of repeated denials of responsibility by the gas industry. The story of Pavillion reveals not only that drinking water is at risk of chemical contamination from fracking operations but also that swift mitigation of such disasters is far from assured. The wheels of science grind slowly while the lives of people have remained in harm’s way.

We are also troubled by the discovery that drinking water wells located near active gas wells here in the Marcellus region contain methane levels that are 17 times higher than those located near inactive wells (Holzman, 2011; Osborn, Vengosh, Warner, & Jackson, 2011) and by the reports of spiking bromide levels in the rivers of western Pennsylvania that followed discharges of fracking wastewater into sewage treatment plants last spring (Hopey, 2011). While methane and bromide are not suspected carcinogens, they serve as precursors for the creation of trihalomethanes, which can form when water is chlorinated. Trihalomethanes are associated with both bladder and colorectal cancers (Weinberg, Krasner, Richardson, & Thruston, 2002).

6. Preliminary evidence points to high rates of cancer in intensively drilled areas. In Texas, breast cancer rates rose significantly among women living in the six counties with the most intensive gas drilling (Heinkel-Wolfe, 2011). By contrast, over the same time period, breast cancer rates declined within the rest of Texas. In western New York State – where vertical gas drilling has been practiced since 1821 and has resulted in significant contamination of soil and water – rural counties with historically intensive gas industry activity show consistently higher cancer death rates than rural counties without drilling activity. In women, cancers associated with residence in a historically drilling-intensive county include breast, cervix, colon, ovary, rectum, uterus, and vagina. Men living in the same region are consistently in the highest bracket for deaths from cancer of the bladder, prostate, rectum, stomach, and thyroid (Bishop, 2011), (based on National Cancer Institute cancer mortality maps and graphs).

While these correlations do not prove a connection between abnormally high rates of cancer and gas industry pollution, they do offer clues for further inquiry. We in the cancer advocacy community believe that this inquiry must precede, not trail behind, any decision to bring hydro-fracking to New York State. Benefit of the doubt goes to public health rather than to the forces that threaten it.

7. Fracking operations will undermine New York State efforts to prevent chronic disease. New York State currently funds important projects, such as the creating Healthy Places to Live, Work and Play programs, many of which are being carried out in rural or small-town communities. Objectives of this initiative include increasing the availability and accessibility of places to be physically active and creating landscapes conducive to physical activity, such as playgrounds and walking trails. It is clear that the industrialization of the landscape where fracking would occur – with increased truck traffic and reduction in air quality described above – undermines these initiatives.

As cancer advocates, we know that regular physical activity lowers the risk for many common cancers. Indeed, the American Cancer Society attributes one-third of all cancer diagnoses to sedentary lifestyles, obesity, and poor diet and thus specifically advocates for land use and urban design that encourages outdoor exercise: “Let’s make our communities safer and more appealing places to walk, bike, and be active” (American Cancer Society). Fracking does the opposite. No one wants to walk, bike, or jog along roads filled with 18-wheelers hauling hazardous materials and filling the air with diesel exhaust. Changes to the built environment that discourage outdoor recreation and promote sedentary behavior will increase our state’s cancer burden and further fan the flames of rising health care costs.

8. The proposed mitigation strategies set forth in the revised environmental impact statement are insufficiently protective. The revised environmental impact statement makes no attempt to explicate the possible human health effects that may result from permitting thousands of gas wells within New York State and from filling our roadways with the fleets of trucks that will service them – or to project the monetary costs of these health effects. Rather, the document asserts, axiomatically, that no such health effects will occur because each gas well will be surrounded by a buffer zone that sets it apart from residential areas and public drinking water sources. But set-backs, like non-smoking sections inside airplanes, are imaginary circles that cannot contain volatile, inherently toxic substances when they are released from multiple sources into interconnected environmental media. We all breathe the same air, and we all live downstream. The best science shows us that cancer is the end result of multiple stressors adding together over time to alter the genetic signaling pathways within our cells (President’s Cancer Panel Report, 2010) When it comes to cancer, the cumulative impact of many small straws is what breaks the camel’s back.

9. Chemical disclosure requirements, health registries, and after-the-fact bio-monitoring programs cannot substitute for due diligence. Disclosing the chemicals used in fracking operations, monitoring human exposures to those chemicals, and establishing registries of those harmed by chemical exposures are useful tools for scientific study and are basic to a transparent, right-to-know democracy, but they do not, by themselves, protect public health. Instead, we need a precautionary, prevention-oriented approach to reducing environmental cancer risk. Drawing on scientific research conducted here in New York and concluding that “… the true burden of environmentally induced cancer has been grossly underestimated,” the 2008-2009 Annual Report of the President’s Cancer Panel, calls on state governments to take action to reduce and eliminate toxic exposures implicated in cancer causation before human harm occurs (President’s Cancer Panel, 2010). To permit a form of fossil fuel extraction that opens countless portals of toxic contamination – upon commencement of the fracking operation and in perpetuity – turns us away from a meaningful approach to cancer prevention.

Full text of the letter including references and supporting organizations is available here.

Fracking Photo: Jim Blecha


Barb Harris is a writer, researcher and activist. Her focus for the last decade has been the human health impacts of environmental toxins and finding healthier alternatives. For the last year, she has researched the health impacts of shale gas and fracking. She is a Board member of the Environmental Health Association of Nova Scotia, and co-author of the on-line Guide to Less Toxic Products. She lives in River John, Nova Scotia.

Also in the Winter 2012 Issue of An Ounce …

Published: February 3, 2012