ASSOCIATIONS OF UNCONVENTIONAL NATURAL GAS DEVELOPMENT WITH ASTHMA EXACERBATIONS AND DEPRESSIVE SYMPTOMS IN PENNSYLVANIA by Sara Rasmussen A dissertation submitted to Johns Hopkins University in conformity with the requirements for the degree of Doctor of Philosophy Baltimore, Maryland April, 2017 Abstract Background: Unconventional natural gas development (UNGD) has proceeded rapidly in Pennsylvania, which now accounts for over 25% of the country’s unconventional natural gas production. UNGD has been associated with air quality and community impacts. Objectives: 1) Evaluate associations of UNGD metrics with asthma exacerbations. 2) Compare different approaches to UNGD activity assessment with one another and in associations with mild asthma exacerbations. 3) Evaluate associations of UNGD metrics with depression symptoms. 4) Evaluate whether and how other aspects of UNGD (impoundments, compressor engines, flaring events) should be incorporated into UNGD activity metrics. Methods: The health studies were conducted using electronic data from the Geisinger Clinic in Pennsylvania. We created UNGD metrics for four phases of well development. We conducted a nested case-control study comparing asthma patients with exacerbations to asthma patients without exacerbations from 2005-12. We then re- evaluated the mild exacerbation associations after replacing our UNGD metrics with those used in prior studies. We evaluated the association of UNGD metrics with depression symptoms ascertained from questionnaire data. We identified UNGD-related impoundments, compressor engines, and flaring using crowdsourcing, abstraction of paper records, and satellite data, respectively, and conducted a principal component analysis (PCA) of UNGD metrics created for wells, impoundments and compressor engines. Results: From the mid-2000s through 2015, 9,669 wells were drilled in Pennsylvania. We found consistent associations of UNGD metrics with three types of asthma exacerbations. Comparing UNGD metrics created in different studies, metrics had ii different magnitudes of association with mild asthma exacerbations, though the highest category of each metric (vs. the lowest) was associated with the outcome. In the depression study, the UNGD metric was associated with depression symptoms. We identified 361 compressor stations, 1,218 impoundments, and 216 locations with flaring events. The PCA identified that a single component captured most of the variation between metrics and was approximately an equal mix of the metrics for compressors, impoundments, and well development. Conclusions: UNGD metrics were associated with asthma exacerbations and depression symptoms and were robust to increasing covariate control and in sensitivity analyses. Determining if these associations are causal requires further research, including more detailed exposure assessment. Thesis readers: Brian Schwartz, Karen Bandeen-Roche, Hugh Ellis, and Paul Strickland Alternates: Jessie Buckley, Mary Fox, and Holly Wilcox iii Acknowledgments I could not have completed this thesis without the support of many, some of whom I would like to thank here. Brian Schwartz has been a tremendous mentor. He provided both freedom to pursue my own ideas and structure to complete this thesis. Thank you for so generously giving expertise and time, and for teaching me to be an environmental epidemiologist. I am so grateful for the opportunities he has provided me. I want to thank Hugh Ellis, Karen Bandeen-Roche, Holly Wilcox, Meredith McCormack, Kirsten Koehler, Paul Strickland, and Anne-Marie Hirsch for their guidance and insight. I also would like to thank Chris Heaney and Ana Navas-Acien for leading journal club, which has been instrumental to my education. Thanks to my fellow Hopkins students for their friendship and support, and thanks to Jon Pollak and Joan Casey for all of their help. Thanks to Cindy Parker for encouraging me to pursue a Ph.D. as a master’s student and providing mentorship throughout my time at Johns Hopkins. I would like to thank the Johns Hopkins Bloomberg School of Public Health for providing me with a great education. Thanks also to the School of Engineering and the IGERT program, namely Grace Brush and Shahin Zand, for broadening my horizons. This thesis would not be possible without the collaboration with Geisinger, and I would like to thank Dione Mercer and Joe DeWalle. I would also like to thank the team at SkyTruth for their collaboration. Thank you to my parents, Joan and Per Rasmussen, for their encouragement from preschool through 22nd grade; and thank you to my family: Lisbeth Rasmussen; Robert Jacobs, and Andrea, Tony, and Kristin Rogers. Thank you to friends: Nicole Tatz and Marta Schantz, who spent countless hours with me at every coffee shop in DC, and Ruth Mandelbaum, Hillary Smith, and Becca Shareff, for a group text that kept me sane. Finally, thank you to Tim Rogers for his love and support, and for helping me spell all the hard words in this thesis. Thanks for sticking with me through three degrees. iv Table of Contents Abstract ........................................................................................................................... ii Acknowledgments .......................................................................................................... iv Table of Contents ............................................................................................................ v List of tables .................................................................................................................... x List of figures ................................................................................................................. xii List of equations ............................................................................................................ xii Chapter 1: Introduction ................................................................................................. 1 1.0 Rationale ................................................................................................................1 1.1 Unconventional natural gas terminology ................................................................. 1 1.2 Unconventional natural gas development in the United States ............................... 3 1.3 Development of a shale gas well ............................................................................ 3 1.4 Environmental and social impacts .......................................................................... 4 1.4.1 Soil impacts .....................................................................................................7 1.4.2 Water impacts ................................................................................................. 7 1.4.3 Air impacts ......................................................................................................8 1.4.4 Community and social impacts ...................................................................... 11 1.5 UNGD and health studies ..................................................................................... 12 1.5.1 Occupational studies of UNGD ...................................................................... 13 1.5.2 Epidemiology studies of UNGD ..................................................................... 13 1.6 The use of electronic health records for epidemiology studies ............................. 19 1.6.1 Overview of the Geisinger Clinic and its EHR ................................................ 19 1.6.2 Environmental epidemiology studies using the Geisinger EHR ...................... 20 1.7 Outcomes selected for study in this thesis ........................................................... 21 1.7.1 Epidemiology of asthma and asthma exacerbations ...................................... 22 1.7.1.1 Overview and definition of asthma exacerbations ................................... 23 1.7.1.2 Asthma exacerbations and air pollution ................................................... 24 1.7.1.3 Asthma exacerbations and stress ........................................................... 28 1.7.2 Epidemiology of depression ........................................................................... 30 1.7.2.1 Association of community characteristics and depression symptoms ...... 30 1.7.2.2 Association of environmental variables and depressive symptoms ......... 32 1.7.3 Relationship between depression and asthma ............................................... 35 1.8 Specific aims ........................................................................................................ 35 1.9 References........................................................................................................... 36 Chapter 2: Detailed Methods ...................................................................................... 52 2.0 Chapter overview ................................................................................................. 52 2.1 Data sources ........................................................................................................ 52 2.1.1 Geisinger Clinic ............................................................................................. 52 2.1.2 Pennsylvania Department of Environmental Protection ................................. 52 2.1.2.1 Natural gas wells ..................................................................................... 52 2.1.2.2 Compressors ..........................................................................................