The Health Impacts of
Fracking and Natural Gas Production
Our nation is experiencing a rush of oil and gas drilling—largely brought
about by the use of horizontal drilling and hydraulic fracturing (fracking).
Fracking involves pumping water, sand, and chemicals underground to
create cracks in tight shale formations and release the natural gas trapped
inside. These techniques have spurred the development of new energy
resources, but at the cost of severe environmental and health impacts in
communities across the country.
Millions of Americans live, work, play, and attend school
warrants more extensive scientific research, but we already
on or near lands being drilled and fracked for natural
know enough to be seriously concerned: Gas production
gas, and there is growing evidence that this activity is
contaminates our air, water, and soil with toxic chemicals,
highly dangerous, and potentially deadly. This evidence
including carcinogens. Despite this, the gas industry has
1t
been granted loopholes in major environmental laws
intended to protect our health and environment. Too often,
CHEMICALS IDENTIFIED VS. CHEMICALS LEFT UNIDENTIFIED
(IN TONS)
Chemicals unidentified
Methanol (Methyl Alcohol)
companies are not held accountable for the pollution they
cause or are not required to fully disclose the chemicals
they use for fracking.
Tertrametyle Ammonium Chloride
Potassium Hydroxide
Petroleum Distillate Hydrotreated Light
41.16
65.47
Ammonium Persulfate
Fracking fluid consists of water, sand, and, typically,
Glutaraldehyde
dozens of chemicals from a list of hundreds of potential
Ethylene Glycol
Trisodium Ortho Phosphate
12.87
Dangerous
Ammonium Persulfate
Hydrogen Chloride
compounds, many of which are toxic. Among the many
dangerous components are:
• Oil, diesel, and other petrochemicals
Chemicals used at a fracked well in Pennsylvania
(Business Insider)
• Volatile organic compounds like toluene, ethylbenzene,
and xylenes, which can damage the nervous and
respiratory systems
• Carcinogens including benzene and formaldehyde,
both of which are volatile organic compounds
• Lead, sulfuric acid, and crystalline silica
Still, it’s nearly impossible to know with confidence which
chemicals are being used at specific fracking sites because
most states don’t require gas companies to fully disclose
the chemicals they’re using. This means that people living
on or near fracking sites are too often left in the dark
when it comes to the chemicals being injected under their
Furthermore, natural gas production has been exempted
from key provisions of major laws governing water
contamination. These loopholes in critical laws—
including the Clean Water Act, Safe Drinking Water Act,
and the Resource Conservation and Recovery Act—
allow companies to inject toxins near aquifers, create
potentially hazardous stormwater runoff, and dispose of
fracking waste without being held to the same health and
safety standards as other industries.
homes or nearby lands. If someone gets sick after drinking
It’s impossible to know how many people have been
water or breathing air polluted by gas drilling, doctors may
harmed by gas-related drinking water contamination—
not know which chemicals to blame—and if they can find
partly because most states don’t require the disclosure
out, they might not be able to tell their patients. 2
of fracking chemicals, and partly because gas companies
often reach legal settlements with affected families.
Water
These cases usually require landowners to sign non-
One significant health risk posed by drilling and fracking
is drinking water contamination. Natural gas production
requires large volumes of hazardous chemicals to be
transported, stored, and pumped belowground. Poor
regulation throughout the process creates countless
opportunities for leaks, spills, and other accidents.
Aboveground, spilled chemicals can pollute waterways
and soils. Belowground, methane, fracking fluids, and
wastes can migrate into the aquifers that people and
communities rely on for drinking water. The process of
handling and disposing of fracking wastes—which can
contain radioactive materials, among other hazardous
substances—is also risky and poorly regulated. Gas
companies are too often allowed to store waste in open
pits, which have been known to leak and overflow,
contaminating soils, waterways, and aquifers.
disclosure agreements, preventing the public from finding
out about contamination events.
Despite carefully parsed industry claims that the
fracturing of shale rock has never been proven to
contaminate drinking water, families in many states have
suffered from drinking water contaminated by natural
gas production, including the fracking process. In Ohio’s
Geauga County, state investigators determined in 2008
that a badly constructed well had allowed methane to
enter a groundwater aquifer, contaminating at least 22
water wells and causing an explosion in a Bainbridge
Township household.3 In Colorado, a Denver Post
investigation found that 17 percent of oil and gas spills
were causing groundwater contamination.4 Across the
country, communities have seen their water turn brown5
after the start of fracking operations nearby, and many
families have reported suffering from headaches, nausea,
difficulty breathing, intestinal illnesses, and inflammation
of the skin and eyes.6
Air
Oil and gas drilling leads to the release of copious
amounts of air pollutants which escape into the
atmosphere in many different ways, including accidental
leaks, excess methane venting, and vehicular emissions
from the trucks that transport water, sand, and chemicals
to wells. States like Wyoming and Utah, once known
for their pristine air, have been among the states most
affected by this pollution. In Wyoming’s Upper Green River
Basin, which is dotted with hundreds of gas wells, smog
Tap water contaminated by methane catches fire in a
Pennsylvania home (Nina Berman / NOOR / Redux)
levels higher than those typically seen in Los Angeles have
been recorded, and residents have complained of watery
eyes, difficulty breathing, and bloody noses.7 Among the
most dangerous chemicals emitted during the natural gas
production process are:
• Volatile organic compounds (VOCs) including
toluene, ethylbenzene, and xylene, which are listed as
“hazardous air pollutants” under the Clean Air Act, and
benzene and formaldehyde, which are carcinogens
• Nitrogen oxides, which react with sunlight to create
ground-level ozone (smog)
• Methane, a greenhouse gas many times more powerful
than carbon dioxide and a significant contributor to
global climate change
• Hydrogen sulfide, which leads to irritation of the
eyes, nose, and throat, and which can cause nausea,
vomiting, and death in extreme cases
Researchers have found elevated levels of smog, methane,
and VOCs where gas production is taking place. One
study showed that people living close to drilling sites face
a heightened risk of emissions-related health impacts.8
Fracking also requires huge quantities of sand, which is
mined and shipped to drilling pads. Inhaling silica particles
from sand can cause deadly diseases like silicosis and
cancer, and workers at both mining and drilling sites are at
risk.
Compounding this problem, gas production is exempt
shale gas workers are thought to be silicosis and cancers
from a key provision of the Clean Air Act.
associates with hydrocarbon exposures (e.g., leukemia) as
This loophole forces regulators to treat individual oil
well as respiratory and dermal diseases related to these
and gas wells as unique sources of pollution, rather than
exposures.”10 One analysis found unsafe levels of silica in
aggregating them. As a result, gas companies that frack
four-fifths of air samples taken at 11 fracking sites.11
many wells in close proximity can avoid adequate scrutiny
And as with all of the health risks associated with gas
and emit unsafe levels of hazardous chemicals.
production, the full extent of the risk is not yet known,
At-risk groups
because the science is still developing. In a discussionof
Some groups face heightened health risks from the air and
water contamination caused by gas production. Expectant
mothers and their unborn children are particularly
vulnerable to the air pollutants, many of which can cause
birth defects and fertility problems. Other at-risk groups
natural gas workers, the American Public Health
Association wrote that the “rapid pace and geographic
scope of expansion [of natural gas extraction] into remote
locations inhibit monitoring of the drill sites to better
understand and protect against the health risks involved.12
include children, the elderly, and people with respiratory
Solutions
conditions, who are most vulnerable to the effects of
The Sierra Club opposes the expansion of drilling and
ozone.
fracking in states and federal landscapes where it is
Natural gas workers might face the greatest risks. These
not currently happening.In areas experiencing gas
workers are potentially exposed to chemicals, silica
development, we must make drilling and fracking safer
particles, and fracking waste on a daily basis, and they
by strengthening standards and closing loopholes that
are routinely injured in drilling and vehicular accidents.9
exempt oil and gas companies from federal laws that exist
In a report for the National Academy of Sciences, experts
to protect the public health and natural environments.
wrote that “the principal chronic morbidity concerns for
To that end, the Sierra Club has
endorsed the BREATHE, FRESHER,
CLEANER, and FRAC Acts, which
would close oil and gas industry
loopholes in the Clean Air Act, Clean
Water Act, Resource Conservation
and Recovery Act, and Safe Drinking
Water Act, respectively. We also
support the SHARED Act would
require testing of water sources
near planned fracking sites to
establish baseline conditions and
determine the source of any water
contamination. We urge Congress to
pass these important, commonsense
bills. Meanwhile, we must continue
to study the health impacts of
natural gas production and use,
so as to better understand the
risks and prevent more damage in
communities where fracking is now
occurring.
More broadly, the Sierra Club is
as committed to developing longterm, clean-energy solutions as
it is to opposing dirty fossil fuels.
We are working at the local, state,
and federal levels to move our
nation toward clean, renewable
energy sources like wind, solar, and
geothermal.
endnotes
1 Hays, Jake and Adam Law. “Public Health Concerns of Shale Gas Development.” Environmental Health Policy Institute, Physicians for
Social Responsibility. June 18, 2012.
2 Tsou, Walter. “The Big Secret? Fracking Fluids.” Environmental Health Policy Institute, Physicians for Social Responsibility. June 18,
2012.
3 “Report on the Investigation of the Natural Gas Invasion of Aquifers in Bainbridge Township of Geauga County, Ohio.” Ohio
Department of Natural Resources, Division of Mineral Resources Management. Sept. 1, 2008.
4 Finley, Bruce. “Drilling spills reaching Colorado groundwater; state mulls test rules.” Denver Post. Dec. 9, 2012.
5 Peltier, Laurel. “The Hagy Story: Loopholes Shield Fracking Industry While Families Pay the Price.” EcoWatch. Feb. 27, 2013.
6 Cantarow, Ellen. “Fracking ourselves to death in Pennsylvania.” Salon. May 2, 2013
7 Koch, Wendy. “Wyoming’s smog exceeds Los Angeles’ due to gas drilling.” USA Today. March 9, 2011.
8 McKenzie, Lisa, of the Colorado School of Public Health. “Human Health Risk Assessment of Air Emissions from Development of
Unconventional Natural Gas Resources.” Science of the Total Environment. 2012.
9 Vaidyanathan, Gayathri. “Death on the gas fields illustrates high risks of the rush to drill.” E&E Publishing, LLC. Feb. 21, 2013.
10Adgate, John L, Bernard D. Goldstein, and Lisa M. McKenzie. “Extended Abstract to Proposed White Paper: Public Health Risks of
Shale Gas Development.” May 17, 2013.
11 Esswein, Eric, et al. “Worker exposure to crystalline silica during hydraulic fracturing.” NIOSH Science Blog, Centers for Disease
Control and Prevention. May 23, 2012.
12 “The Environmental and Occupational Health Impacts of High-Volume Hydraulic Fracturing of Unconventional Gas Reserves.”
American Public Health Association. Oct. 30, 2012.
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