Integrated effort needed to mitigate fracking while protecting both humans and the environment
Efforts to mitigate the potentially harmful effects of fracking have traditionally been divided along two fronts – those that primarily focus on protecting the environment and wildlife, and those that focus on protecting humans and domestic animals.
But it doesn’t have to be that way. In a March 30 commentary in Bioscience, a trio of public health experts, ecologists and environmental scientists urge adoption of a more holistic approach when evaluating the impact of unconventional gas and oil production operations such as fracking. They also lay out a framework for future transdisciplinary collaboration and integrated decision-making, which they say will lead to more just and comprehensive solutions that protect people, animals and the environment.
“Researchers and policymakers tend to focus on only one domain, when they really are interconnected,” said Nicole Deziel, Ph.D., the paper’s lead author and an associate professor of epidemiology (environmental health sciences), environment and chemical and environmental engineering at Yale University. “This paper provides strategies to promote approaching oil and gas extraction industries and their impacts in a more holistic, interdisciplinary way.”
Joining Deziel on the paper are Liba Pejchar, Ph.D., a professor in the Department of Fish, Wildlife and Conservation Biology at Colorado State University and the study’s senior author; and Bhavna Shamasunder, Ph.D., associate professor, chair of the Department of Urban and Environmental Policy and co-chair of the Department of Public Health at Occidental College.
The interdisciplinary collaboration on the paper, entitled “Synergies and trade-offs in reducing impacts of unconventional oil and gas development on wildlife and human health,” came about during a workshop on the community impacts of oil and gas development that Deziel attended several years ago. She was fascinated by Pejchar’s and Shamasunder’s presentations and discussed the crossovers in their perspectives during a long bus ride to a fracking well pad. That impromptu interaction, Deziel said, highlights the value of conferences that include representatives of different disciplines, one of the paper’s recommendations.
Hydraulic fracturing, more commonly known as fracking, is a method for extracting gas and oil from shale rock. The process involves injecting water, sand and chemicals into bedrock at high pressure, which allows gas and oil to flow into a well and then be collected for market.
Used extensively in the U.S., fracking has led to heightened concerns about its impact on the environment and human health. The process creates vast amounts of wastewater, emits greenhouse gases such as methane, releases toxic air pollutants and generates noise. Studies have shown these gas and oil operations can lead to loss of animal and plant habitats, species decline, migratory disruptions and land degradation. They have also been associated with human health risks. Studies have reported associations between residential proximity to these operations and increased adverse pregnancy outcomes, cancer incidence, hospitalizations and asthma. Some fracking-related operations have been located near lower-resourced communities, worsening their cumulative burden of environmental and social injustices.
In their paper, the authors describe how past protection measures, however well-intended, have sometimes favored one interest (the environment and wildlife for instance) at the expense of another (humans and domestic animals) and vice versa. Deziel used setbacks and buffers as an example. Setbacks aim to protect human health by prohibiting gas and oil drilling within a certain distance of homes, schools and other community domains. However, this approach may encroach on animal habitats, shifting the threat from humans to animals and the natural world. Buffers are similarly implemented, but with a goal of protecting wildlife and sensitive environmental areas. In contrast, limiting drilling altogether would be protective of both people and animals.
“The solutions are not being addressed in an integrative way,” said Deziel, whose primary appointment is with the Yale School of Public Health. “It’s important to protect vulnerable human populations as we’re making solutions, and we should also be mindful of the impacts to the ecosystem and the ecological world for their own intrinsic value.”
The authors recommend scientists and practitioners take a more integrated approach that spans both public health and conservation interests and focuses more on regions and populations that are underrepresented, historically marginalized or poorly understood. They cite One Health initiatives as an example of how a wide range of collaborations can work. One Health is a collaborative, multisectoral and transdisciplinary concept that has been primarily applied to address infectious diseases and optimize human health outcomes while recognizing the interconnection among people, animals, plants and their shared environment.
Deziel said she hopes the paper – and its recommendations – will inspire future collaborations across the fields of ecology, social science and public health, and encourage more inclusive decision-making that includes input from people and organizations directly affected.
JOURNAL
BioScience
METHOD OF RESEARCH
Commentary/editorial
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
Synergies and trade-offs in reducing impacts of unconventional oil and gas development on wildlife and human health
ARTICLE PUBLICATION DATE
30-Mar-2022
Pinpointing the sound of failure
Researchers identify critical signature produced when rocks fail
Peer-Reviewed PublicationIMAGE: SUPERVISED MACHINE LEARNING FOUND THAT NEGATIVE TURNING (BLACK POINTS) AND POSITIVE TURNING (WHITE POINTS) AMPLITUDE MEASUREMENTS ACROSS A NEUTRAL ZERO LINE (GREY POINTS) HAPPENED IN CONCERT WITH ROCK FRACTURE MOMENTS. view more
CREDIT: RUI LIU, TEXAS A&M ENGINEERING
Finding the specific sound a rock makes when it cracks and breaks seems impossible when surrounded by other subsurface noises. But Texas A&M University researcher Dr. Siddharth Misra, the Ted H. Smith, Jr. ’75 and Max R. Vordenbaum ‘73 DVG Associate Professor in the Harold Vance Department of Petroleum Engineering, discovered a way to hear and validate that sound in a project funded by the Basic Energy Sciences program of the Department of Energy (DOE).
“The DOE calls sounds of specific events the ‘signs of signature,’” said Misra. “In this case, the signature identified the break or mechanical discontinuity of a rock in the earth’s subsurface, especially as the breaks continued to grow or propagate into fractures.”
Misra and his doctoral candidate Rui Liu published their preliminary findings in the May 2022 issue of the Systems and Signals Processing journal.
Why does Basic Energy Sciences want this signature identified? Sounds are often important clues to environmental and security changes. Threatening noises, such as underground explosions, are hard to mistake. But the small sounds of a high-rise building foundation cracking and failing are just as threatening. So, the fundamental sound of rock undergoing mechanical failure is a basic and critical clue worth finding.
“This research goes to the heart of identifying something specific within a massive data set,” said Misra. “An example is credit card transactions. You cannot monitor the whole data set for fraud because the transactions are so varied. You must find some indicative sign, such as a credit card charge in one city to book an airline flight immediately after that same card pays for an Uber in another city. That discrepancy is a signature.”
Previous attempts to pinpoint underground mechanical failures never brought reliable success, but Misra found that an unusual combination of three research methods — supervised machine learning, causal discovery and rapid simulations — could tackle the problem.
The supervised machine learning began with lab experiments in which a multipoint sensor system was placed on the surface of a rock and recorded sound wave-transmission measurements through the material as it cracked and finally failed. Computers monitored the information and were taught which data signatures meant initial, intermediate and end-stage damage. One tell-tale signature that repeatedly traveled up and down across the zero point between positive and negative measurements caught the computer’s attention, once it knew what to look for.
“I can only see the color or shape of something with my eyes,” said Liu. “But machine learning can pick out so many more characteristics from the data. It picked out those positive and negative turnings, and we used that sign to get further results.”
Misra and Liu searched for the causation of each of these turnings to confirm their source. They couldn’t rely on the computer to complete this step because machine learning is not the best interpreter.
“During the heat of the summer, ice cream sales increase and drowning deaths increase,” said Misra. “If you use machine learning or simple statistical methods, they might say people are drowning because people eat ice cream. That's a correlation. Though they are both related to the summer heat, they are not connected to each other. They each have a different cause. We are looking for causation for these turnings because that's when they become meaningful.”
Misra and Liu created a workflow that could generate scenarios of various fracture propagations and measured waveforms. Then, they increased the workflow’s speed to rapidly run up to 20,000 different simulations of possibilities for each event. This allowed the researchers to discover the best cause-and-effect explanations.
“We didn’t control how the discontinuity propagated, so there's a lot of randomness,” said Misra. “Yet, as the fractures grew, despite the differences in direction or length, results showed a similar increase in amplifications or positive and negative turnings across the zero point in the waveforms. So, this is a definite signature of rock failure, which, to the best of my knowledge, was not known prior to this research.”
While the signature discovery is exciting, the project still has several months to go. Misra intends to explore the limits of the data-driven simulations and causal discovery approach. He will also test other methods to see if similar or different results occur.
“What we need to do as scientists, as engineers, is to find causality, find causation,” said Misra. “We tried a lot of different techniques to discover this signature and its causal relationships. A lot of approaches didn't work, but one did. Now we need to find the limits of what it can do.”
METHOD OF RESEARCH
News article
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
Monitoring the propagation of mechanical discontinuity using data-driven causal discovery and supervised learning
ARTICLE PUBLICATION DATE
1-May-2022
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