A Medical Perspective on
Oil and Gas Development
Mansfield TX
October 29, 2014
Anne C. Epstein MD, FACP
Lubbock TX Board of Health
Health Risks
of Oil and Gas Development
1. Toxic Air Emissions:
2. Human Health Impacts
Associated with Air
3. Risk of Groundwater
4. The Precautionary
Principle and Public
Image credit: Zach Long/Lubbockonline (Seminole)
Toxic Air Emissions: Benzene
A highly toxic carcinogen that occurs
naturally in oil and gas
• VOC-volatile organic compound
Long-term health effects
• Leukemia- a “Group 1 Carcinogen”
• Life-threatening anemia
• Immune system suppression
• Possible fetal abnormalities
High levels of exposure
• Coma, seizures, irregular heart rhythms,
fluid in the lungs, death
Children and developing fetuses are more
vulnerable to all toxic air emissions
ATSDR August 2007, ww.atsdr.cdc.gov/toxicprofiles/tp3.pdf,
CDC Emergency Safety and Health Database
Paulson, Testimony before House Subcommittee Feb 2014
NIOSH Study of Oil & Gas
Worker VOC Exposure
August 2014
A flowback technician gauging a
flowback tank through a hatch on top
of the tank
• Measured worker exposure to VOCs
at 6 completion sites in Colorado &
• 15 of 17 benzene samples exceeded
the recommended 8 hr exposure
limits for workers gauging flowback
or production tanks
• Benzene exposures were variable,
unpredictable, and sometimes very
– 200 ppm close to open tank
hatches- several readings
– Recommended 15 min exposure
limit: 1 ppm
• Conclusions: Benzene levels
reached concentrations that
potentially pose health risks for
Esswein et al, J of Occupational and Environmental
Hygiene, 11:10, 01 Aug 2014
TCEQ Barnett Shale Study 2009
• 94 monitoring sites surveyed 2009
– Flyover, GasFindIR cameras, VOC monitors
• Air samples collected at 73 sites
• Benzene was detected above the long term health based
comparison value (> 1.4 ppb) at 21 monitoring sites in 12
different areas
• 2 sites required immediate action for value > 180 ppb
– 1 compressor station:1100 ppb
– 1 gas well: 15,000 ppb (5 feet from the well)
– Both repaired, came into compliance
TCEQ Interoffice Memo Jan 27, 2010, “Health Effects Review of Barnett Shale Formation Area
Monitoring Projects” and Sadlier & Honeycutt, “TCEQ Barnett Shale Update” 2010
VOC emissions captured on infrared
camera by TCEQ 2009
Heavy VOC emissions captured by infrared
camera at Aruba facility in the Barnett Shale
Screenshot of a TCEQ video posted by D. Hasemyer, Center for Public Integrity, May 28 2014
Air Toxin Concentrations During Well
Completion in Garfield County CO
(McKenzie et al, Science of the Total Environment, 22 March 2012)
Natural Gas Development
Area > 1/2 mile away
Well Completion samples
150-500 ft from well pad
center during
uncontrolled flowback
Flyover Air Monitoring in Colorado
 Airborne measurements of air pollutants – 12 flights
in May 2012
 Correlated with atmospheric data
 Results: Benzene emissions were between 7 and 9
times higher than estimated by State of Colorado
Petron et al, American Geophysical Union, May 2014
Human Health Impacts
Associated with O & G Air Emissions
Health Impact Assessment from the
Colorado School of Public Health 2012
Measured hazardous air pollutants at different distances from
O&G wells
Near: 500 feet and less from a well
Far: > ½ mile from a well
Found elevated levels of
hazardous air pollutants
near wells : Benzene, Toluene, Ethyl benzene, Xylene (BTEX)
Calculated the risk of illness under 2 different scenarios:
Subchronic: short term , high intensity- well completions
Chronic: long-term , lower intensity- well production
McKenzie et al, Science of the Total Environment 22 March, 2012
Non-cancer Hazard Indexes by duration of
exposure and distance from Source
Adgate , National Academy of Health Workshop, 2012
Hazard indexes by health end point: Near wells,
20 month exposure scenario
(Adgate 2012, National Academies of Health, Health Impact Assessment of Shale Gas Extraction:
Workshop Summary)
Birth Outcomes and Maternal Residential Proximity to
Natural Gas Development in Rural Colorado
The data: 1996 - 2009
• All birth records in rural Colorado (Rural sites chosen to avoid
air pollution from cities)
• All hospital and clinic records of birth defects
• Records of location and year built for all gas wells in rural
Total 124,842 births
• Researchers analyzed level of maternal exposure to gas wells:
how far away and how many gas wells at the time of birth
• 3 groups: low, medium, and high exposure
• Reference group: no gas wells within 10 miles
McKenzie et al, Environmental Health Perspectives, 28 January 2014
Birth Outcomes and Maternal Residential Proximity to
Natural Gas Development in Rural Colorado
McKenzie et al, Environmental Health Perspectives, 28 January 2014
Number of babies born with
Congenital Heart Disease
Compared to 0 wells w/in 10
10% increased risk for 1-3 wells/
mile , low exposure (281 births)
20% increased risk for 4-124
wells/ mile, medium exposure (300
30% increased risk
for > 125
wells/ mile, high exposure (355 births)
Statistical significance p< 0.001
Adjusted for multiple factors
Rabinowitz et al (Yale), Environmental
Health Perspectives Sept 2014
• Subjects: Randomly chosen,
180 households/ 494
individuals with a private
water well in Washington
County PA
• Exposure: 624 active
natural gas wells in
Washington County in 2012
• Study: Survey regarding
health symptoms
Image credit: B. Mark Schmerling (Washington
Rabinowitz et al, Environmental Health
Perspectives Sept 2014
Rabinowitz et al, Environmental Health Perspectives Sept 2014
Compared to people living > 2
km from the nearest gas well,
People living < 1 km away had
a greater incidence of:
• Upper respiratory
symptoms (39% vs 18%)
• Skin symptoms (13% vs 3%)
• Average number of
reported symptoms (3.3 vs
Results statistically significant
even after adjustment for
multiple factors
Image from Parr Family, Lisa Parr’s daughter, Emma
(published by CNN) TX
Confirmed Cancer Cluster
in Barnett Shale: Flower Mound TX
• Breast Cancer
– 369 cases, expected number
303 (2002-2011)
– 99% confidence interval
statistically significant
• Benzene
– Possible cause of breast
Texas Department of State Health Services, July
30, 2014.
Institute of Medicine 2011, “Breast Cancer and
the Environment”
Image credit: National Cancer Institute
Private Drinking Water Wells and Risks
due to Groundwater Contamination
• 15 million Americans rely on
private drinking water wells
that use groundwater
• Drinking contaminated
groundwater can cause
human illness
• EPA regulations that protect
the public water supply do
not apply to private wells
• Water quality testing is at
the owner’s discretion
Groundwater Contamination from Oil
and Gas Activities in Pennsylvania
Reported by the Pennsylvania
Dept. of Environmental
Protection, August 28, 2014
• 243 cases where “DEP
determined that a private
water supply was impacted
by oil and gas activities”
2008 – 2014
• 1.2 % of the total number
of wells
Hess, PA Environmental Digest Aug 29, 2014
DEP, Regional Determination Letters, Aug 29 20I4
Image credit: AP Photo/Ralph Wilson
Groundwater Contamination from Oil
and Gas Development in Texas
Reported by the Railroad
Commission of Texas
• 532 total cases in 2013
• 72 new cases in 2013
– Benzene, other BTEX,
Hydrocarbons, crude
oil, and other toxins
Texas Groundwater Protection Committee,
“Joint Groundwater Monitoring and
Contamination Report 2013,” April 2014
Groundwater Contamination from
Surface Spills in Colorado
• 77 spills of oil or produced
water reported in 1 year
(July 2010-July 2011) that
contaminated groundwater
• Benzene exceeded
maximum contaminant
levels in groundwater - 90%
• 16% of the spills had not
been remediated as of May
• Average spill: 1000 gallons
Gross et al, Journal of the Air & Wastewater
Management, 20 March 2013, Image credit
Casing and Cementing
Failures in Pennsylvania
• 41,000 oil and gas wells
– After 2009, most were unconventional
• Data source: state inspection reports
• Results
– Overall structural failure rate = 1.9%
– Unconventional wells in drilling boom
area failure rate = 9.18%
– Each additional inspection prior to 2009
increased the chances of finding a
structural failure by 17.7%
Ingraffea et al, PNAS May 30, 2014
Graphic by Al Granberg/ProPublica
Toxic Effects of
Arsenic in
Drinking Water
Image credit:
• Arsenic : a major public health concern
according to the World Health
• Colorless and tasteless: may be
undetected in drinking well water for
many years
• Long term exposure effects
– Cancer of the skin, bladder, lungs, and
possibly of the kidney, liver, and
prostate. “Group 1 Carcinogen”
– Diabetes, kidney disease, high blood
pressure, heart attacks and stroke
– Blood cell, liver, and nerve ending
– Skin thickening and rashes
– In pregnant women: spontaneous
abortion, stillbirth
WHO, “Exposure to Arsenic: a Major Pubic Health Concern” 2010
Arsenic in Private Water Wells
in the Barnett Shale, Texas
• 100 private water wells sampled
– 91 from active area
• ( 1 or more gas wells
within a 5 km radius)
– 4 from non-active area
• (no gas wells within a 14
km radius)
– 5 from reference site outside
the Barnett Shale
• (no gas wells within a 60
km radius)
• Compared with historical data
from 330 private wells from the
same area 1989-1999, before gas
Fontenot et al, Environmental Science and
Technology 25 July 2013
% of Water Wells with Arsenic/ Selenium Levels
Greater than Maximum Contaminant Limits
Fontenot et al, J. Environ Sci. Technology, July 31, 2013
The Precautionary Principle
• “When an activity raises threats of harm to the
environment or human health, precautionary measures
should be taken even if some cause and effect
relationships are not fully established scientifically.”
– Endorsed by the US Government *
– Endorsed by the American Public Health Association as a
“cornerstone of preventive public heath policy and
1998 Wingspread Statement on the Precautionary Principle
*in signing the Rio Declaration on Environment and Development in 1992
**American Journal of Public Health 91(3), March 2001, pl. 495

Health and Environmental Impacts of Oil and Gas Developement