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Tanja Srebotnjak
Miriam Rotkin-Ellman
Natural Resources Defense Council
Fracking Fumes: Air Pollution from
Hydraulic Fracturing Threatens
Public Health and Communities
N R DC ISSuE BRIEF
december 2014 Ip:14-10-a
Just off Interstate Highway 25, Drill Rig in front of homes in the town of Frederick in Weld County, Colorado. pipes, vehicles and storage tanks also stand in front of homes as hazy, snow capped Rocky Mountains stand in the background.
InTroducTIon
H
ydraulic fracturing (‘fracking’) and other well stimulation methods have led to a rapid expansion
of oil and gas development in the united States.^1 This expansion has brought oil and gas
development closer to backyards and communities and increased the potential for human
exposure to new contaminants and threats. at the same time, a growing body of new research points
to health threats from unconventional oil and gas development and fracking in particular. although
health discussions, particularly in eastern states, have focused on drinking water contamination, there
is mounting evidence for a range of health threats from air pollution as well. For example, research
has linked pollution from fracking to unhealthy levels of smog and of toxic air contaminants. Exposure
to this pollution can cause eye, nose, and throat irritation, respiratory illnesses, central nervous system
damage, birth defects, cancer, or premature death.^2 at the same time, the oil and gas industry has
been exempted from many regulations that limit air pollution from industrial activity.^3 at the federal
level, the Environmental protection agency (Epa) recently issued new standards to limit harmful
air pollution from the oil and gas industry—but these still contain major gaps.^4 Health protective
regulations are also hampered by lack of scientific data on the potential cumulative risks posed by the
combined emissions from a dense network of wells and associated infrastructure such as pipelines,
compressor stations, and roads. State regulations are patchy and enforcement often cannot keep up
with the industry’s rapid expansion, resulting in insufficient protection from air pollutants.
HeAlTH sTudIes FInd ImPAcTs From
FrAckInG-relATed AIr PolluTIon
Conventional oil and gas production has been known
for some time to create harmful air emissions.^5 With the
increase in fracking activity, more and more studies now
document emissions of airborne pollutants at and near
fracking sites that are known to cause cancer and harm the
nervous, respiratory, and immune systems (see Figure 1).
At the same time, people and communities in areas with
many hydraulically fractured wells report health problems
consistent with these types of exposures. 6,7,8,9,10^ While it is
difficult to measure actual exposures to pollutants from
nearby fracking operations and establish clear links to
adverse health outcomes, some studies found associations
between air pollutants that are present at oil and gas
production sites and health impacts observed in nearby
communities. 11,12^ In Colorado, for example, an evaluation
of birth defects in areas with high concentrations of oil and
gas activity found that mothers who lived near many oil and
gas wells were 30 percent more likely to have babies with
heart defects. 13 Similarly, preliminary results from a study in
Pennsylvania show impacts among newborns that could be
linked to air pollution such as increases in low birth weight.^14
In many rural areas, the boom in oil and gas activity has
been linked to unhealthy spikes in ozone concentrations. 15
In 2008 and 2011, increased ozone concentrations in
Wyoming’s Sublette County were associated with subsequent
increases in outpatient clinic visits for respiratory problems. 16
Researchers who looked at air pollution levels near fracking
sites in Colorado also found an increased risk of chronic and
sub-chronic effects mainly stemming from oil and gas related
pollutants, which can harm the respiratory and neurological
systems and lead to symptoms like shortness of breath,
nosebleeds, headaches, dizziness, and chest tightness. 17
Thus, while research into the health effects of air pollution
from unconventional oil and gas development is ongoing,
there is mounting evidence that it causes pollution, which
can affect the health of workers and communities.
AIr PolluTIon From FrAckInG
A comprehensive literature review identified 15 different oil
and gas development processes and sources—including the
drilling process, wastewater, and condensate tanks—that
can release air contaminants (see Figure 2 in the Appendix). 18
The authors conclude that “there is legitimate concern that
local air pollution may produce adverse effects in individuals
who live near the high emitting site or processes.” The rapid
expansion of fracking, both in areas with existing oil and
gas operations and previously undrilled areas, can lead
to an increase in the type of pollution generally found at
conventional oil and gas development and to other pollutants
specific to fracking, such as silica sand, fracking chemicals,
and flowback wastewater.
local Impacts
diesel emissions
Diesel emissions originate from the combustion engines
of heavy trucks and machinery used during well site
preparation, drilling, and production. Exhaust from diesel
engines contains hundreds of toxic chemicals. Of greatest
concern is the fine diesel soot particles, which can lodge
deep within the lungs, increasing health risks including:
emergency room visits, hospital admissions, asthma attacks,
cardiopulmonary disease (including heart attack and stroke),
respiratory disease, adverse birth outcomes, and premature
death (from pneumonia, heart attack, stroke and lung
cancer).19,20^ Researchers are concerned about local residents’
increased risk of exposure to diesel exhaust.^21 A study of
regional air quality impacts from natural gas extraction in
Pennsylvania’s Marcellus Shale included diesel emissions
from truck traffic, well drilling and hydraulic fracturing, gas
production, on-site combustion, and compressor stations in
the monetary damage calculations.^22 The National Institute
for Occupational Safety and Health (NIOSH) expressed
concern about the levels of diesel particulate matter
measured at 11 oil and gas sites in Colorado, Arkansas,
Pennsylvania, Texas, and North Dakota. 23
Toxics
Toxic air pollutants originate from direct and fugitive
emissions of hydrocarbons at the well and from associated
infrastructure such as condensate tanks, dehydrators,
wastewater impoundment pits, and pipelines. The fracking
process involves dozens of chemicals and the process returns
oil, gas, fracking chemicals, formation brines, and mobilized
compounds, including heavy metals and naturally occurring
radioactive materials (NORM) to the surface.
Hydrogen sulfide (H 2 S) is a toxic and explosive gas that
may be present in oil and gas formations and is produced
along with the hydrocarbons. It is damaging to the central
nervous system and can be lethal at higher concentrations
(~1000 ppm).^24 While oil and gas workers may be required
to wear protective respirators, 25 no such protections are
considered for surrounding communities.
Benzene, toluene, ethylbenzene, and xylene (BTEX) and
other toxic hydrocarbons, such as formaldehyde, released
from oil and gas operations and equipment can lead to health
impacts ranging from irritation of eyes, nose, mouth, and
throat to aggravated asthma and other respiratory conditions,
blood disorders, harm to the developing fetus, immune
system-related diseases, and cancer (e.g., leukemia, non-
Hodgkins lymphoma).
A study commissioned by the West Virginia Department
of Environmental Protection found that, at many sites,
a 625-feet distance from oil and gas activity—above the
distances set by many states—still resulted in benzene
concentrations above levels the Center for Disease Control
and Prevention (CDC) considers “the minimum risk level
for no health effects.” 26 At least one of the BTEX compounds
was found at all of the seven drilling sites examined. A health
risk assessment in Colorado’s heavily drilled Garfield County
identified many hydrocarbon pollutants (including trimethyl-
benzenes, aliphatic hydrocarbons, and xylenes) associated
with adverse respiratory and neurological effects. 27 It further
found that concentrations of benzene, toluene, ethylbenzene,
and xylene increased with proximity to the well site and were
up to nine times higher during well completion than during
well production. In tight gas fields in rural northeastern Utah,
researchers estimated the total annual mass flux of volatile
organic compounds (VOCs) from the surveyed gas fields
to be equivalent to the emissions from 100 million cars.^28
The benzene levels measured in this study also exceeded
health standards set by the Agency for Toxic Substances
Disease Registry (ATSDR) and the California Environmental
Protection Agency (CalEPA) to protect against harm to the
developing fetus, immune system and blood.
silica
Silica—the main component of ‘frac sand’—is used widely
and in large quantities to hold open the fractures created
during the fracking process. 29 Inhalation of respirable silica
can cause silicosis, an irreversible lung disease, 30 as well as
lung cancer in miners, sandblasters, and foundry workers.^31
Silica inhalation is now also recognized as an occupational
health hazard among oil and gas workers. NIOSH researchers
collected 111 personal breathing zone (PBZ) samples at
11 sites in 5 states. At each one, they found that full-shift
samples exceeded occupational health criteria,^32 in some
cases by 10 times or more. This means that even if workers
are properly using half-mask air-purifying respirators,
they would not be sufficiently protected, because the
measured concentrations exceed the masks’ maximum use
concentration.^33
regional Pollution
ozone smog
Fracking-related processes and other stages of the oil and gas
production process release nitrogen oxides and VOCs, which
react in the presence of sunlight to form ozone (‘smog’).
Exposure to ozone is associated with a variety of respiratory
and cardiovascular effects, including shortness of breath,
reduced lung function, aggravated asthma and chronic
respiratory disease symptoms, inflammatory processes,
and premature death. 34 A growing number of studies have
attributed emissions of ozone precursors from rapidly
growing oil and gas development^35 to significantly elevated
ozone concentrations in Wyoming, 36 Colorado, 37 Utah, 38,39,
Pennsylvania, 41,42^ Texas, 43,44^ and Oklahoma. 45 In the study on
Wyoming’s Sublette County, tight gas production activities
caused winter ozone levels 46 to spike above the EPA’s 8-hour
ozone standard of 75 parts per billion 13 times between
February 14 and March 15, 2011.^47 In Utah’s Uintah Basin
ambient 1-hour ozone levels exceeded 150 ppb—twice the
federal standard. 48
Workers not Protected
In addition to the community health concerns from fracking,
worker safety at oil and gas production sites is also coming
under increased scrutiny, in part because the oil and gas
industry is one of the most dangerous occupational sectors
in the country. According to statistics released by the Bureau
of Labor Statistics there were 545 fatalities at U.S. oil fields
between 2008 and 2012, of which 216 occurred in Texas. 49
At this level, the industry’s fatality rate is 2.5 times higher
than the accident-prone construction sector and more
than 8 times higher than the industrial sector as a whole.^50
A major contributing factor to the industry’s high fatality
rate are traffic accidents, which also impact neighboring
communities.
On-site toxic exposures present another health hazard
to oil and gas workers. In 2010, at least four worker deaths
may be linked to chemical and petroleum vapor exposure
at or near flowback tanks at oil well sites in North Dakota
and Montana. 51 Air samples collected by NIOSH in the
personal breathing zone of workers at six flowback sites
in Colorado and Wyoming identified benzene as the primary
VOC of concern, especially near the hatches of the flowback
tanks. Of the 17 samples, 15 met or exceeded the NIOSH
Recommended Exposure Limit (REL) of 0.1 ppm. 52
The unprotected inhalation of silica dust and diesel fumes
also threatens worker health and may lead to cancers and
other illnesses many years after exposure. 53 Workers may even
bring contaminated clothes and boots home, putting their
families at risk.
currenT PolIcIes And reGulATIons ProvIde InAdequATe HeAlTH ProTecTIons
The oil and gas industry enjoys numerous exemptions
from parts of key environmental and health protection
laws, including the Clean Air Act, the Clean Water Act, and
Hazardous Waste Laws. 54 These exemptions lead to weak
regulations and inadequate monitoring for air pollutants
and toxins from oil and gas facilities. As fracking and other
extreme stimulation techniques move closer to towns and
cities, this creates an information, legal, and regulatory
vacuum that hampers communities’ knowledge of and ability
to protect themselves from harmful oil- and gas-related
emissions and associated health impacts.
Faulty Inventories underestimate Air Pollution
State and federal inventories provide important information
for tracking and regulating air emissions of greenhouse
gases, VOCs, and other hazardous air pollutants. Recent
research indicates that these inventories may significantly
underestimate air pollution from the oil and gas sector for
a variety of reasons, including data gaps, uncertainty in the
efficiency of emissions control equipment, use of obsolete
or unrealistic emissions factors, incomplete reporting
by operators, and changes in industry practices. One
investigation led by the National Oceanic and Atmospheric
Administration (NOAA) in Colorado’s heavily drilled Denver-
Julesburg Basin concludes that the state inventory for total
VOCs emitted by oil and gas activities—which contribute
to ozone formation and cause local toxicity—may be too
low by a factor of at least two and that benzene emissions
are seven-fold higher than reported in the state inventory.^55
An earlier systematic review of eleven “top-down” (starting
with levels of pollutants in the atmosphere and attributing
those emissions to sources) and a number of “bottom-up”
(starting with measurement of a set of sources’ emissions
and extrapolating to aggregate emissions) studies looking
at methane emissions from the sector estimates that total
U.S. methane emissions from all sources were 25 percent to
75 percent higher than the U.S. Greenhouse Gas Inventory
estimates for 2011, and finds that oil and gas are important
contributors to these unreported emissions.^56 This review
also concludes that a small number of “superemitters”
could be responsible for a large fraction of the industry’s
methane leakage that had not been accounted for in the
Inventory. In sum, the studies strongly suggest that oil and
gas development is making a larger contribution to climate
change than previously thought and that inventories may
underestimate other pollutants.
n Comprehensive characterization of all pollution sources in
unconventional oil and gas development and quantitative
assessment of pollutants and emission rates through
research and updated federal and state inventories
n Improved air quality monitoring before, during, and
after well development and around all sources
n Expansion of the federal and state ozone monitoring
network to better characterize air quality in rural
areas highly impacted by pollution from oil and gas
development
n Identification and implementation of adequate and
protective setback requirements to reduce the exposure
of residents to intermittent and chronic levels of air
pollutants and toxins^70
n Closure of regulatory loopholes in federal environmental
programs to fill data gaps, increase transparency and
oversight of the oil and gas industry and ensure public
health protections
n Rigorous scientific studies in regions with intensive
oil and gas development examining the effects of air
pollution on the health of the local population, including
comprehensive health impact assessments prior to new
site development and followed by ongoing evaluations. 71
WHAT resIdenTs cAn do
Residents can take the following actions to reduce their potential exposure to dangerous air pollutants:
Get informed
n Learn about possible pollution in your area:
n Visit the U.S. EPA website for information on ozone and particulate levels
n Contact your state environmental agency or health department for information on local monitoring for other
air pollutants
n Visit NRDC’s Don’t Get Fracked! Information Center to learn how to protect yourself and your family from
pollution linked to hydraulic fracturing
n For more information on specific oil and gas-related pollutants visit:
n Benzene
n Hydrogen sulfide (H 2 S)
n Diesel
n Other toxics
n If you are worried about health symptoms or impacts, make sure to see your doctor and consult healthcare
providers knowledgeable about the health impacts of air pollution. More resources are available through the
following organizations:
n The Pediatric Environmental Health Speciality Units (PEHSU)
n Association of Environmental Medicine Clinics
Protect the most vulnerable
n Young children, the elderly, and individuals with respiratory conditions (e.g., asthma) can be sensitive to lower
levels of pollution and should avoid exercise or extended outdoor activity when odors are present or agency
websites (EPA or state) indicate poor air quality.
Take Action
n Improve air quality monitoring in your community
n Report spills and other environmental problems in your community
n Connect with your neighbors and set up a Citizen Science group
n Speak up and organize your community’s defense
n Demand stronger protections
Learn more at: nrdc.org/energy/gasdrilling
LOCAL POLLUTION
REGIONAL POLLUTION
GLOBAL POLLUTION
PRODUCTION
3
PROCESSING & STORAGE
4
5^ TRANSMISSION WELL ABANDONMENT (^6) & SITE REHABILITATION
drIllInG: diesel PM, NO (^) x , CO 2 , CO, BTEX, PAH, CH 4 , volatile drilling mud fluids, and volatile hydrocarbons from drill cuttings HYDRAULIC FRACTURING: silica dust, volatile fracturing chemicals, BTEX, and other volatile hydrocarbons, PM, NO (^) x , CO 2 , CO FLOWBACK AND PRODUCED WATER: volatile fracturing fluids, BTEX, and other volatile hydrocarbons, H 2 S
Trucks And HeAvY mAcHInerY: diesel PM, NO (^) x , CO 2 , CO, BTEX, PAH, dust
Trucks And HeAvY mAcHInerY: diesel PM, NO (^) x , CO 2 , CO, BTEX, and PAH ABANDONED / ORPHANED WELLS: CH (^4)
Produced WATer: BTEX, and other volatile hydrocarbons, H 2 S
GAS FLARING/VENTING: CH 4 , NO (^) x , CO 2 , CO, PM, H 2 S, BTEX, and other volatile hydrocarbons
WORK-OVER AND MAINTENANCE: diesel PM, NO (^) x , CO 2 , CO, CH 4 , BTEX, PAH, and other volatile hydrocarbons
WELL SITE PREPARATION
AND ROAD CONSTRUCTION
WELL DRILLING, HYDRAULIC
(^2) FRACTURING & WELL COMPLETION
BTEX: benzene, toluene, ethylbenzene, and xylene; CH 4 : methane; CO: carbon monoxide; CO 2 : carbon dioxide; H 2 S: hydrogen sulfide; NOx: nitrogen oxides; PAH: polycyclic aromatic hydrocarbons; PM: particulate matter
PIPelInes: CH 4 , BTEX, and other volatile hydrocarbons COMPRESSOR STATIONS: diesel PM, NO (^) x , CO 2 , CO, BTEX, PAH, and other volatile hydrocarbons GAS VENTING: CH 4 , H 2 S, BTEX, and other volatile hydrocarbons
GAs venTInG: CH 4 , H 2 S, BTEX, and other volatile hydrocarbons
SEPARATORS AND CONDENSATE TANKS: CH 4 , BTEX, and other volatile hydrocarbons
COMPRESSORS: diesel PM, NO (^) x , CO 2 , CO, BTEX, PAH, and other volatile hydrocarbons
APPendIx
Figure 2: major air pollutants and air toxics released during the different fracking process stages and sources of
equipment
Table 2: Health impacts of the main air pollutants by target organ and system
Pollutant Target organ/system carcinogen
Particulate matter (Pm)
Diesel pM Respiratory system; Cardiovascular system (^) •
pM 10 and smaller Respiratory system; Cardiovascular system
volatile organic compounds (vocs)
Benzene Immune system; Blood; Fetal development, Nervous System (^) •
Toluene
Brain and nervous system; Respiratory system; Fetal and child development;
Reproductive system
Ethylbenzene
Fetal and child development; Liver; Kidney; Endocrine system;
auditory system •
Xylene Brain and nervous system; Fetal and child development
Other VOCs (incl.
Formaldehyde, Methanol)
Immune system; Respiratory system; Brain and nervous system;
Fetal and child development; Liver; Kidney; Endocrine system •
other
Hydrogen sulfide (H 2 S) Respiratory system; Brain and nervous system; Gastrointestinal system
NOx Respiratory system
Ozone (O 3 ) Respiratory system; Cardiovascular system
Respirable Silica Respiratory system; Kidneys; Immune system (^) •
paHs (incl. Naphthalene)
Immune system, Reproductive system; Brain and nervous system*;
Developmental effects* • **
** probable carcinogens are among the paHs emitted at unconventional oil & gas sites
Sources: Factsheet on the Health Effects of Diesel Exhaust. available at http://oehha.ca.gov/public_info/facts/dieselfacts.html. u.S. Epa (1997). Health Effects of particulate Matter. OaQpS Fact Sheet, July 17, 1997. available at www.epa.gov/region7/air/quality/pmhealth.htm. OSHa (2014). Crystalline Silica, www.osha. gov/dsg/topics/silicacrystalline/health_effects_silica.html. aTSDR (2004). Interaction profile For: Benzene, Toluene, Ethylbenzene, and Xylenes (BTEX). aTSDR (2007). public Health Statement for Benzene. available at www.atsdr.cdc.gov/phs/phs.asp?id=37&tid=14. aTSDR (2000). public Health Statement for Toluene. available at http://www.atsdr.cdc.gov/phs/phs.asp?id=159&tid=29. aTSDR (2010). public Health Statement for Ethylbenzene. available at www.atsdr.cdc.gov/ phs/phs.asp?id=381&tid=66. aTSDR (2007). public Health Statement for Xylene. available at www.atsdr.cdc.gov/phs/phs.asp?id=293&tid=53. Department of Health and Human Services, Centers for Disease Control, National Institute for Occupational Safety and Health. 2005. NIOSH pocket Guide to Chemical Hazards: Benzene. 2005-149. National Institute for Occupational Safety and Health (NIOSH). www.cdc.gov/niosh/npg/npgd0049.html. Department of Health and Human Services, Centers for Disease Control, National Institute for Occupational Safety and Health. 2005. u.S. Epa. an Introduction to Indoor air Quality. Volatile Organic Compounds. available at www.epa.gov/iaq/voc.html. aTSDR (1995). public Health Statement for polycyclic aromatic Hydrocarbons (paHs). available at www. atsdr.cdc.gov/phs/phs.asp?id=120&tid=25. u.S. Epa. NIOSH pocket Guide to Chemical Hazards: Hydrogen Sulfide. 2005-149. National Institute for Occupational Safety and Health (NIOSH). www.cdc.gov/niosh/npg/npgd0337.html. aTSDR (2002). Factsheet on Nitrogen Oxides. California Epa, Office of Environmental Health Hazard assessment (OEHHa). Health Effects of Ozone in the General population. available at www.epa.gov/apti/ozonehealth/population.html.
Key: BTEX: benzene, toluene, ethylbenzene, xylene; CH 4 : methane; diesel pM: diesel particulate matter; H 2 S: hydrogen sulfide; NOx: nitrogen oxides; O 3 : ozone; paH: polycyclic aromatic hydrocarbons; pM 10 : particulate matter of 10 micrometers or smaller in diameter.
endnotes 1 u.S. Energy Information administration, “Today in Energy. North america leads the World in Shale Gas production,” www.eia.gov/today- inenergy/detail.cfm?id=13491 (accessed June 6, 2014).
2 John L. adgate et al. “potential public Health Hazards, Exposures and Health Effects from unconventional Natural Gas Development,” Environ- mental Science and Technology", 2014 doi:10.1021/es404621d).
3 u.S. Government accountability Office (GaO), “ Unconventional Oil and Gas Development. Key Environmental and Public Health Require- ments ,” GaO-12-874.
4 The new rules still allow existing facilities to release up to 1 ton per year of the carcinogen benzene from large glycol dehydrators despite analysis showing that this could increase the cancer risk for neighbor- ing communities. Existing facilities are also not required to upgrade their equipment to reduce emissions and protect public health.
5 u.S. Environmental protection agency, “Improving air Quality in Your Community,” www.epa.gov/oaqps001/community/details/oil-gas_addl_ info.html (accessed September 3, 2014).
6 Elizabeth Ridlington, John Rumpler, “ Fracking by the Numbers: Key Impacts of Dirty Drilling at the State and National Level” , Environment america Research & policy Center and the Frontier Group, 2013.
7 Charles W. Schmidt, “Estimating Wastewater Impacts from Fracking,” Environmental Health Perspectives 121 (4) (2013): a117. doi:10.1289/ehp.121-a117.
8 Roxana Z. Witter et al., Potential Exposure-Related Human Health Effects of Oil and Gas Development: A Literature Review (2003- 2008) , White paper, Denver, CO, 2008, docs.nrdc.org/health/files/ hea_08091702b.pdf (accessed august 21, 2014).
9 Roxana Z.Witter et al., Health Impact Assessment for Battlement Mesa, Garfield County Colorado , aurora, CO, 2010, www.garfield-county. com/public-health/documents/1%20%20%20Complete%20HIa%20with- out%20appendix%20D.pdf (accessed august 21, 2014).
10 peter M. Rabinowitz et al. “proximity to Natural Gas Wells and Reported Health Status: Results of a Household Survey in Washing- ton County, pennsylvania,” Environmental Health Perspectives , 2014, doi:http://dx.doi.org/10.1289/ehp.1307732.
11 Lisa M. McKenzie et al., “Human Health Risk assessment of air Emissions from Development of unconventional Natural Gas Resources,” Science of the Total Environment 424 (2012): 79–87, doi:10.1016/j.scito- tenv.2012.02.018.
12 Lisa M. McKenzie et al., “Birth Outcomes and Maternal Residential proximity to Natural Gas Development in Rural Colorado,” Environmental Health Perspectives , (2014), doi:http://dx.doi.org/10.1289/ehp.1306722.
13 Ibid. [12].
14 John L. adgate et al., “potential public Health Hazards, Exposures and Health Effects from unconventional Natural Gas Development,” Environmental Science & Technology , (2014), doi:10.1021/es404621d.
15 Detlev Helmig et al., “Highly Elevated atmospheric Levels of Volatile Organic Compounds in the uintah Basin, utah.” Environmental Science & Technology , March 27, 2014. doi:10.1021/es405046r.
16 State of Wyoming Department of Health, “ Associations of Short- Term Exposure to Ozone and Respiratory Outpatient Clinic Visits — Sub- lette County, Wyoming, 2008–2011,” 2013, Cheyenne, WY.
17 Ibid. [11].
18 Ibid. [14].
19 Seth B. Shonkoff et al. Environmental public Health Dimensions of Shale and Tight Gas Development. Environmental Health perspectives. (2014).
20 John L. adgate et al. “potential public Health Hazards, Exposures and Health Effects from unconventional Natural Gas Development," Environ- mental Science and Technology”, 2014 doi:10.1021/es404621d. 21 allen Robinson, “ Air Pollutant Emissions from Shale Gas Develop- ment and Production ,” Workshop presentation on the Health Impact assessment of New Energy Sources: Shale, Institute of Medicine, april 30-May 1, 2012. 22 aviva Litovitz et al., “Estimation of Regional air-Quality Damages from Marcellus Shale Natural Gas Extraction in pennsylvania,” Environ- mental Research Letters, 8 (2013), doi:10.1088/1748-9326/8/1/014017. 23 Eric J. Esswein, Michael Breitenstein, John Snawder, “ NIOSH Field Effort to Assess Chemical Exposures in Oil and Gas Workers: Health Hazards in Hydraulic Fracturing ,” Workshop presentation on the Health Impact assessment of New Energy Sources: Shale, Institute of Medicine, april 30-May 1, 2012. 24 Ibid. [14]. 25 Occupational Safety and Health administration (OSHa), “ Standards for Hydrogen Sulfide ”, www.osha.gov/SLTC/hydrogensulfide/standards. html (accessed June 6, 2014). 26 West Virginia Department of Environmental protection, Division of air Quality, “ Air, Noise, and Light Monitoring Results For Assessing Environmental Impacts of Horizontal Gas Well Drilling Operations (ETD‐ Project) ,” Charleston, WV. 27 Ibid. [11]. 28 Ibid. [15]. 29 according to industry representatives, hydraulic fracturing compa- nies use up to 10,000 tons of silica sand to hydraulically fracture a single well. See Kanika Sikka, Sneha Banerjee, “ U.S. Silica Sees Sand Demand Piling up as Fracking Goes Super-Sized ,” Reuters, September 19, 2014. www.reuters.com/article/2014/09/19/us-ussilica-demand-iduSKBN- 0HE12p20140919. 30 Long-term exposure can lead to chronic silicosis, while short-term exposure to very large amounts of silica can cause acute silicosis. 31 OSHa, “ Silica, Crystalline ,” www.osha.gov/dsg/topics/silicacrystal- line/ (accessed September 4, 2014). 32 The criteria used in the study are the Occupational Safety and Health administration calculated permissible exposure limit (pEL), the NIOSH recommended exposure limit (REL), or the threshold limit value (TLV) set by the american Conference of Industrial Hygienists (aCGIH). 33 Eric J. Esswein et al., “Occupational Exposures to Respirable Crys- talline Silica during Hydraulic Fracturing.” Journal of Occupational and Environmental Hygiene 10 (7) (2013): 347–56, doi:10.1080/15459624. 3.788352. 34 uS Epa, “ Health Effects of Ozone in the General Population ,” www. epa.gov/apti/ozonehealth/population.html (accessed June 13, 2014). 35 Christopher W. Moore et al., “air Impacts of Increased Natural Gas acquisition, processing, and use: a Critical Review,” Environmental Sci- ence & Technology , 11 (2014), doi:dx.doi.org/10.1021/es4053472. 36 Wyoming Department of Environmental Quality. “ WDEQ Winter Ozone Update ,” public Meeting, pinedale, WY, March 22, 2011. 37 Gabrielle pétron et al., “a New Look at Methane and Non-Methane Hydrocarbon Emissions from Oil and Natural Gas Operations in the Colorado Denver-Julesburg Basin,” Journal of Geophysical Research: Atmospheres (2014), doi: 10.1002/2013JD021272. 38 Ibid. [15]. 39 Seth Lyman, Howard Shorthill, “ Final Report: 2013 Uintah Basin Winter Ozone & Air Quality Study ,” CRD/9.273a, Vernal, uT: utah State university, 2013.
