shale gas development health · shale gas development & health brian s. schwartz, md, ms johns...
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Shale gas development & health
Brian S. Schwartz, MD, MSJohns Hopkins Bloomberg School of Public Health, Baltimore, MD
Geisinger Health System, Danville, PA
Mid-Atlantic Regional COEM Conference (MARCOEM)
September 23, 2017
Outline1. Brief: contexts of energy and shale gas2. Overview of unconventional natural gas
development (UNGD)3. Environmental and community impacts of UNGD4. The Geisinger Health System and its Environmental
Health Institute5. Published research
a. Birth outcomesb. Asthma exacerbationsc. Nasal and sinus, migraine headache, and fatigue
symptoms6. Ongoing research7. Questions 2
2017
2016
2016
What is Fracking?
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• Short for hydraulic fracturing− Water, chemicals, and sand are injected into geologic formations to get oil and natural gas to flow to surface
− Used for unconventional fossil fuels
• Represents only a short period of the entire development and production cycle
• I have done studies of unconventional natural gas development (UNGD) and health
NAP 2015
Why Are We Fracking?
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• We are going after unconventional resources for fossil fuels because production from conventional resources is flat and increasing levels of investment have not increased production
• Do you think we would be going after more difficult resources if the easier, cleaner, and more profitable stuff was still available?
• We are entering the era of “tough energy”
These are now mostly depleted
The Resource Pyramid: Fossil Fuels are FINITE and Limits are Being Reached
Mobility = K/µK = permeability of formationµ = viscosity of oil or gas
Quality of resource increases in this direction
Cost, environmental impact, risk increase in this direction
End 2016: Marcellus shale:
• With Utica, provided 85% of shale gas growth since 2012
• ~38% of U.S. shale gas production
Plot from WikipediaData from EIA
Natural gas: mainly CH4, 24% of all energy used in US; 32% for industrial uses, 24% electricity, 22% residential,
14% commercial, 8% other
Should You Still be Uncertain About Human‐caused Climate Change?
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Today, there is no scientific rationale to argue against these statements:1. The world’s climate is changing2. Humans are the primary cause3. Climate change will have very significant impacts on human health and well‐being
Energy policy is climate policy.Why are we developing another fossil fuel in the age of climate change?
What Are the Implications of the Rapid Production Declines in
Unconventional Natural Gas Wells?
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• Many data sources document that gas production declines very rapidly from unconventional wells− As much as 90% in first three years
• This means to increase gas production over time, must drill an enormous number of wells
• Thus must consider long‐term cumulative impacts of tens of thousands of wells
The Process – A Summary• Roads are built to the drilling area. • Well pad land is cleared, requiring 3‐5 acres. • Water holding ponds (impoundments) are built to collect the water
for hydraulic fracturing, and flow‐back and produced waters.• Pre‐drilling activity requires 400 to 2,000 truck trips to/from site
(well depth, location) diesel exhaust exposures. • The well is then drilled vertically to 7,000‐10,000 feet and
horizontally for another 2,000‐10,000 feet. • Fracking is next, at high pressure with 3‐7M gallons of water mixed
with proppants (sand or other small particles) and organic chemicals (e.g., surfactants, solvents, biocides).
• Surface is prepared to receive natural gas: process (i.e., separate it from other organics and water vapor), compress (diesel‐powered), store (in tanks with relief valves for off‐gassing) and transport(pipeline).
• Waste liquids, primarily water contaminated by salts, organics, and radioactive materials, must be managed.
• From start to pipeline hookup requires a few months.
NAP 2015
Impoundment
Flaring
Vertical component
Horizontal component
Heavy trucks
Compressors, processing, storage
Perforation in pipe
Fractures
Ground water used for well
water
Well head
Chemicals involved in hydraulic fracturing
• Gelling and foaming agents to help create desired fluid rheology, to create fracture volume and area, and to transport proppant material
• Friction reducers to reduce pressure needed to pump fluid into wellbore• Surfactants to optimize hydrocarbon removal by minimizing water oil‐wetting of
rock surface • Cross‐linkers to enhance ability of gelling agent to transport proppant material• Breakers to force the gelling agent to break down into a less viscous fluid to aid
fluid recovery later in process• pH buffers to maintain fracturing fluid in pH range for optimum rheology• Biocides to prevent the growth of bacteria in well• Corrosion inhibitors to prevent degradation of the steel well casing• Scale inhibitors to control the precipitation of carbonate and sulfate materials• Iron control chemicals to inhibit precipitation of iron compounds (keep soluble)• Clay protection chemicals to minimize clay damage to formation from clay
swelling or migration of fine particles
The additives are highly determined by the specifics of the well and the geology and there is variation from well to well in additives.
NAP 2015
Air Impacts
• VOCs around oil and gas operations (Environmental Health, 2014)
− Measured air concentrations of 75 VOCs near oil and gas operations in six states using standard methods
− Levels of 8 VOCs exceeded federal guidelines for exposure level or health‐based (most commonly for benzene, formaldehyde, hexane, & hydrogen sulfide)
− Some benzene levels very high (5.7–110,000 µg/m3)• Fugitive emissions of methane
− An important greenhouse gas, with global warming potential over 100 years ~30X higher than CO2
− EDF & Princeton U study: for electricity, natural gas reduces climate impacts vs. coal if CH4 leakage < 3.2%
− There is continued uncertainty and some controversy about the levels of fugitive emissions
Other Air Impacts
Water Impacts
• Evaluated 141 water wells in northeastern PA
• Measured CH4 concentrations and isotopic signatures (to distinguish biogenic from thermogenic sources)
• CH4 detected in 82% of samples• CH4 6X higher on average in homes <
1km from shale well (p < 0.001)• Ethane 23X higher on average at
homes < 1km from shale well (p = 0.001)
• “… some homeowners living < 1 km from gas wells have drinking water contaminated with stray gases”
• Authors cautioned: findings may not apply to all regions with drilling
Seven scenarios that may account for the presence of elevated hydrocarbon gas levels in shallow aquifers.
2014
How Can UNGD Affect Health?
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Chemical hazards• Air quality impacts – pollution (CAP,
HAP), odors• Water quality impacts – surface, ground• Soil impacts
Physical hazards• Noise, light, vibration, radiation (Rn)
Community impacts• Truck traffic, motor vehicle accidents,
industrializationSocial impacts
• Transient workers, crime, social problemsCombined, cumulative, and chronic impacts
Summary of Health Efforts• Health impact assessments – several (e.g., Witter, AJPH 2013; McKenzie,
Sci Tot Env 2012; Boyle, PLOS One 2016)
• Calls to action – many (e.g., Finkel, AJPH 2013 & 2011; Bamberger, New Solut 2012)
• Review articles, health – several (e.g., Adgate, ES&T 2014; Hays, noise, Sci Tot Env 2017; Moore, ES&T 2014; Webb, Rev Env Health 2016; Hays, PLOS One 2016)
– Hays 2016: “31 original research studies relevant to UNGD and public health hazards, risks, and health outcomes”
• Qualitative research – focus groups are concerned about potential health impacts and believe they are experiencing current health effects (e.g., Ferrar, IJOEH 2013; Sangaramoorthy, Soc Sci Med 2016)
• Survey research – mainly convenience samples (e.g., Steinzor, New Solut 2013; Powers J Comm Health 2015; Saberi IJERPH 2014)
• Empirical epidemiology – around 10 “decent” original health studies; 4 birth outcomes (Stacy, Casey, McKenzie, Hill; one not peer‐reviewed); 2 more of ours; 1 on symptoms (Rabinowitz, EHP 2014); 2 cancer studies (Finkel, Public Health 2016; Fryzek, JOEM 2013 ) ; 1 ecologic study (Jamielita, PLOS One 2015) ;
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June 2012
“While silica exposure most often is linked to construction work … some workers at hydraulic fracturing operations are exposed to …
10X the REL for crystalline silica.”
What Health Studies Have We Done and How?
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• With the Geisinger Health System in the Marcellus shale in Pennsylvania− Birth outcomes (Epidemiology 2016)
− Asthma exacerbations (JAMA Internal Medicine 2016)
− Migraine headache, fatigue, and nasal and sinus symptoms (Environmental Health Perspectives 2016)
• Funded by NIH ES023675 and AI106683
• Using electronic health records or questionnaires mailed to patients
Geisinger, An Integrated Health System• 45+ community practice clinics, 12+ hospitals
• 1.6M patients– In 40+ counties in central and northern Pennsylvania– Expanding south and into New Jersey– Need not have Geisinger insurance to use health system– Varied community types in region, rural to urban
• Electronic health record (EHR) since 2001– 30% of primary care patients have Geisinger Health Plan for
insurance – can get claims data
• EHR provides (these and more)– Demographics, vitals, encounters, dates, diagnoses, testing,
procedures, medications, health insurance, free-text in clinical notes26
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Geisinger, An Integrated Health System
The Geisinger Environmental Health Institute (EHI)
• Founded in 2007
• Investigating a number of environmental issues– Unconventional natural gas development (UNGD)– Industrial food animal production, abandoned coal mine lands,
built environment, land use, social environment, food environment
• Investigating a number of health outcomes– Pregnancy outcomes, asthma, type 2 diabetes, childhood obesity,
mental health, methicillin-resistant S. aureus (MRSA), chronic rhinosinusitis, others
• All EHI research is submitted for publication to peer-reviewed scientific journals
Methods Common to All Studies
• Obtain patient data from EHR• Geocode patients• Consider how environment may contribute
to disease burden• Use geographic information systems (GIS)
to create exposure metrics• Link exposure and patient measures• Biostatistical analysis – person, place, time
Exposure Assessment
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1. How do we rank people (or buildings) along a gradient of exposure potential in epidemiologic studies?
2. How do we do this retrospectively?3. Should we try to capture all potential
health impact pathways at once? Or measure each one separately?
Spudded Wells in Pennsylvania to September 2016 (N = 9996, with 7677 in production) [Source: PA DEP]
Full build out: some estimates > 50,000 wells
UNGD activity metrics get BIGGER if you are surrounded by
Closer wellsMore wellsLarger wells
Q1 Q2 Q4Q3
Minimum
0Maximum
Big #Reference Group
QUARTILES
All wells in state contribute:• Closer: distance residence to well• More: number of wells• Larger: total depth (STIM) or
volume of production (PROD)
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• FOUR phases• mi = 1 (PAD & SPUD); total depth
(STIM); daily gas volume (PROD)• d = distance well to residence• Analyzed separately or combined
Methods• Study population: 10,496 neonates, 9384 mothers Jan 2009 – Jan
2013, singleton births only • Outcomes: birth weight, preterm birth, 5min Apgar score, small for
gestational age; post hoc high risk pregnancy• UNGD activity metric: summed 4 UNGD phases for gestation• Analysis: linear or logistic regression, 3-level model• Adjustment: child: sex, season of birth; mother: age, race/ethnicity,
primary care, smoking, body mass index, parity, family SES, delivery hospital, distance to roads, well water; community: socioeconomic deprivation, greenness
• Sensitivity analyses: examples– Add year (2009-10 vs. 2011-13), gestational age (birth weight models),
use Cox proportional hazards (preterm birth, gestational age timescale)– Assigned children born in 2006 the UNGD activity metric they would have
had were they born in 2012 (expect no association; if yes confounding)
Birth Outcomes Study
Study Area, UNGD Wells, Marcellus Extent, Hospital Locations, and Deliveries by County
Overview of Study and Findings• Scientific rationale: air quality, water quality, and psychosocial
stress all can cause adverse birth outcomes; short latency
• Study population: 10,496 neonates, 9384 mothers 2009–2013, singleton births only
• UNGD activity metric: summed 4 UNGD phases for gestation
• Adjustment: for important child, maternal, and community variables
• Major findings:
− Women residing closer to more or larger wells had increased risk (41-86%) of pre-term birth and high-risk pregnancy
• Sensitivity analyses: examples
– Stronger associations when adjusted for year
– Negative exposure control analysis was negative as expected
• 35,508 asthma patients, aged 5‐90 years between 2005‐12
• Exacerbations− 5600 severe (hospitalization)− 2291 moderate (ED* visit)− 25,647 mild (new OCS med*)
• Assigned exposure on day before exacerbation
• Four UNGD activity metrics• Compared patients with and without exacerbations
• Adjusted for other variables linked to asthma
Asthma Study
* ED = emergency department; OCS med = oral corticosteroid medication
Two sensitivity analyses: 1. County not associated with asthma exacerbations 2. UNGD not associated with diarrheal illness among asthma patients
• Four UNGD activity metrics: PAD, SPUD, STIM, and PROD• Three asthma outcomes: mild (OCS), moderate (ED), and severe (HOSP) exacerbations
PAD with HOSPUNGD SPUD with HOSP STIM with ED PROD with OCS
• All UNGD activity metrics were associated (OR, 95% CI) with all three outcomes• Selected associations:
Design: used Geisinger electronic health record to select 23,700 patients; mailed 4‐page questionnaire; 7847 returned; analysis weighted for selection & response• Designed for study of CRS epidemiology so did not identify UNGD as purpose
Nasal and sinus symptoms (EPOS* chronic rhinosinusitis criteria)• Alone and in combination with other conditions
Migraine headache• 3 validated screening questions for migraine headache (Lipton 2003)• Collected as frequency of occurrence and assigned scores• Alone and in combination with other conditions
Severe fatigue• 8 validated questions for fatigue (PROMIS fatigue short form 8a)• Frequency of occurrence, assigned scores; severe fatigue = score 20+ • Alone and in combination with other conditions
UNGD and Symptoms(NIAID U19 AI106683; Environ Health Perspect 2016)
* EPOS = European Position Paper on Rhinosinusitis and Nasal Polyps
Symptom Study
Results for Symptom Study
• Patients in the highest category of UNGD activity (the fourth quartile of closer to more or larger wells) had significantly increased risk of several symptoms
− 88% increased risk for chronic rhinosinusitis and fatigue together
− 95% increased risk for fatigue and migraine together
− 84% increased risk for CRS, fatigue, and migraine together
EHI Health Studies: Summary• UNGD activity metrics associated with:
– Preterm birth, high risk pregnancy, possibly low birth weight
– Three types of asthma exacerbations– Nasal & sinus, migraine headache, & severe fatigue
symptoms• Associations robust to increasing covariate
control• Associations robust in several sensitivity
analyses• Associations are biologically plausible• We cannot identify pathways or mechanisms 40
Brian Schwartz
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Johns Hopkins UniversityKaren Bandeen‐Roche (biostatistics)Joan Casey (now UCB/UCSF)Tara McAlexander (PhD candidate)Meredith McCormack (asthma)Elizabeth Ogburn (biostatistics)Jonathan Pollak (biostatistics, analysis)Sara Rasmussen (PhD candidate)Aaron Tustin (OEM resident)
Geisinger Health SystemSy BrandauJoshua CrispJoseph DeWalleJennifer IrvingDione MercerAgnes Sundaresan
Brown UniversityDavid Savitz (reproductive)
SkyTruthJohn Amos David Manthos(impoundments, flaring)
Harvard UniversityPeter James (greenness)
Gettysburg CollegeRutherford Platt (impoundments)
