Fracking's Fallout: An interview with YSPH's Nicole Deziel

Nicole C. Deziel, M.H.S., Ph.D., is an assistant professor in the Department of Environmental Health Sciences. Her research focuses on exposure to environmental toxins and the role they may play in the onset of human disease, including those specific to women’s and children’s health. She has investigated several types of pollutants, including pesticides, persistent organic pollutants and polycyclic aromatic hydrocarbons. Her research also includes hydraulic fracturing, or “fracking,” and how chemicals used in the process and released into the air or water may adversely affect communities of people living nearby.

Much of your research is on the possible health consequences associated with hydraulic fracturing, or “fracking.” Can you briefly describe what fracking is?
ND: Hydraulic fracturing and fracking are terms used to describe unconventional oil and gas (UO&G) development, which is a complex process of extracting fossil fuels from deep rock formations. The process involves pumping millions of gallons of pressurized water, sand and chemicals into drilled wells that extend a mile or more below ground to create cracks in the rock, releasing oil or gas. This industry has greatly expanded in the past decade due to advances in drilling and other technologies.

How widespread is fracking in the United States today?
ND: Hydraulic fracturing occurs in at least 25 states. There have been approximately 300,000 wells drilled and hydraulically fractured since 2000. An estimated 10 million people live within one mile of an oil or gas well, potentially placing them in contact with chemicals released into the air or water.

How many chemicals are used in the fracking process and what are some that cause particular concern?
ND: There have been more than 1,000 chemicals produced or emitted by the hydraulic fracturing process. However, fewer chemicals are emitted at any individual well. Our research has demonstrated that chemicals involved in or produced by UO&G development may include known or suspected reproductive and developmental toxicants and carcinogens. These compounds may be released into the air or water, potentially exposing nearby populations. There is limited information about whether this process could contaminate the air or water in nearby communities and whether adverse health effects may result.

What are some of the potential human health effects associated with exposure to these chemicals?
ND: The current evidence regarding the health effects of UO&G development is inconclusive. However, a handful of human health studies of UO&G development have observed an increase in adverse perinatal outcomes; asthma exacerbations; dermal irritation; increased hospitalization rates; nasal, headache and fatigue symptoms; and childhood leukemia.

Are children at particular risk?
ND: Children are often more likely than adults to be at risk from environmental hazards because of their different exposure and activity patterns and their different physiology. Children breathe and drink more relative to their body mass than adults do, and therefore if the air or water is contaminated they may experience a higher dose of the contaminant. Children’s natural defenses are also less-developed. Additionally, they may be vulnerable to damage during rapid growth periods, when their organs and systems are undergoing differentiation and maturation.

Because children are a vulnerable population, research efforts should be directed toward further investigating whether exposure to [fracking] is associated with an increased risk of childhood leukemia.

Nicole Deziel

What are some of the specific diseases potentially associated with fracking that may affect young people?
ND: Increases in adverse perinatal outcomes such as low birth weight and birth defects have been observed in the children of mothers who live in areas with oil and gas activity in the vicinity of their homes. However, additional studies are needed before these effects can be conclusively linked to hydraulic fracturing.

Is there evidence that exposure to a fracking site is associated with leukemia?
ND: It is possible that proximity to UO&G development could increase the risk of childhood leukemia, based on several lines of evidence. We identified 55 known, probable or possible carcinogens (20 of which are associated with leukemia and/or lymphoma specifically) that are potential water contaminants and/or air pollutants related to UO&G development. Our study provides some support for the hypothesis that exposure to UO&G development could increase the risk of leukemia. A new study by researchers in Colorado observed that children with a common form of leukemia were 2.8 times as likely to live near areas of dense oil and gas activity. Furthermore, large influxes of oil and gas workers and their families into rural areas experiencing oil and gas booms could introduce new infectious agents, which could lead to childhood leukemia as well. Because children are a vulnerable population, research efforts should be directed toward further investigating whether exposure to UO&G development is associated with an increased risk of childhood leukemia.

If fracking is occurring far underground, how do people come into contact with the potentially toxic chemicals?
ND: Drilling operations could possibly contaminate drinking water sources through several mechanisms. Pathways of potential groundwater and surface water contamination from UO&G development may include leakage from deteriorating or improperly constructed wells; spills and leaks of hydraulic fracturing fluids and wastewater; improper wastewater storage and treatment; and migration of chemicals from fractures to shallow aquifers. A recent study found that there were 6,622 reported spills associated with 21,300 unconventional wells from 2005 to 2014 in Colorado, New Mexico, North Dakota and Pennsylvania alone.

UO&G development activities that could generate air pollution include operation of diesel-powered equipment; use of vehicles to transport materials and waste to and from the site; addition of sand (silica) to the fracturing fluid mixture; volatilization of compounds from wastewater; processing and distribution of oil and gas; and flaring or burning off gas. Air pollutants such as diesel exhaust, fine and coarse air particulates, crystalline silica and polycyclic aromatic hydrocarbons are examples commonly cited as being generated during various phases of UO&G development.

Is there anything that families who live in close proximity to a fracking site can do to protect themselves and the health of their children?
ND: It is difficult to make specific recommendations due to the limited data available on the potential for increased exposure to harmful chemicals. If people are concerned about their air or water, they could contact state or federal authorities and have their water tested. If they notice any changes in their water, they could substitute bottled water or install a filtration system if feasible.

What are your future research goals in this area?
ND: My research aims to address two critical gaps:
(1) whether people living in communities in close proximity to UO&G operations experience increased exposure to toxic or carcinogenic compounds and (2) whether they experience adverse health effects. 

Read the latest Yale Public Health magazine for insights on global childhood health. 

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This article was submitted by Elisabeth Reitman on January 17, 2018.

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Nicole Cardello Deziel

Assistant Professor of Epidemiology (Environmental Health Sciences)