NIEHS-funded researchers at John Hopkins University (JHU) Bloomberg School of Public Health and their collaborators reported that unconventional natural gas development (UNGD) in Pennsylvania is associated with migraine headaches, fatigue, and nasal and sinus symptoms. Their study represents one of the largest surveys to date of adverse health effects and fracking. The findings were published Aug. 25 in the journal Environmental Health Perspectives.
Rapid expansion of fracking and health concerns
The UNGD process of hydraulic fracturing, or fracking, is approximately 1-2 weeks long and has dramatically increased in the past few years in several states. In Pennsylvania alone, almost 10,000 fracking wells have been drilled in the past decade, according to an article written by three of the study's authors, including Brian Schwartz, M.D., senior researcher for the new study. The researchers pointed out that fracking is linked to pollution of air, soil, groundwater, and surface water, but little research has been done on potential human health effects.
According to the scientists, the effects of fracking on the environment and human health could occur due to the fracking chemicals injected deep into the ground or other chemical pollutants, such as diesel exhaust and combustion products. The authors also hypothesized that UNGD could negatively affect health by creating stressors such as loud noises, vibrations, truck traffic, social disruptions, and unpleasant odors.
Analyzing the link between health and fracking
The team studied 7,785 adults in Pennsylvania to determine associations between fracking wells and various health effects. After mailing questionnaires to primary care patients of the Geisinger Clinic in 39 counties in Pennsylvania, they identified patients who had migraine headaches, fatigue, and chronic rhinosinusitis — a condition that causes a variety of nasal and sinus symptoms that lasts longer than 12 weeks.
The researchers chose these symptoms for this study because they are widespread in the United States and generate costs for healthcare and in lost productive work time. “These three health conditions can have debilitating impacts on people’s lives,” said first author Aaron Tustin, M.D., in a press release.
The authors measured fracking activity by looking at each well’s location, depth, daily gas production, and distance to patient residences. By using sophisticated analysis, the researchers demonstrated significant statistical associations between fracking and nasal and sinus, migraine, and fatigue symptoms in people.
Participants in the group exposed to the highest amount of fracking activity were almost twice as likely to have two or more of the health conditions studied than those exposed to the lowest amount of fracking activity.
Strengths and limitations
“This study is the largest survey so far of symptoms related to UNGD and represents a valuable case-control study,” said Bonnie Joubert, Ph.D., a health scientist administrator in the NIEHS Population Health Branch. “The fact that surveyed participants did not know UNGD was examined in relation to their symptoms reduced the potential for bias in this study, which is a major strength,” she noted.
The authors described several limitations to their work. For example, the study used self-reported health outcomes, which can lead to inaccuracies. Also, the approach to measuring UNGD activity did not allow identification of specific exposure pathways. Although the scientists found a correlation between fracking and health effects, they also highlighted the need to assess whether these associations are causal and what mechanisms may be involved.
Citation: Tustin AW, Hirsch AG, Rasmussen SG, Casey JA, Bandeen-Roche K, Schwartz BS. 2016. Associations between unconventional natural gas development and nasal and sinus, migraine headache, and fatigue symptoms in Pennsylvania. Environ Health Perspect; doi:10.1289/EHP281 [Online 25 Aug 2016].
(Samantha Hall is a postbaccalaureate Cancer Research Training Award (CRTA) fellow in the National Cancer Institute Center for Cancer Research Laboratory of Toxicology and Toxicokinetics, housed at NIEHS.)