Chevron Case: Re 26 - Public - Strauss Expert Report (nov. 7, 2014)

The Matter of An Arbitration Under the Rules of the United
November 7, 2014
Nations on International Trade law
Chevron Corporation and Texaco Petroleum Company v. The
Republic of Ecuador
PCA Case 2009‐23
Supplemental Opinion of Harlee Strauss, Ph.D. Regarding Human Health
Risks and Health Impacts Caused by Crude Oil Contamination in the
Former Petroecuador‐Texaco Concession, Oriente Region, Ecuador
In response to the following:
Expert Opinion of Thomas E. McHugh, Ph.D., D.A.B.T., Regarding Lack of Evidence of
Health Risks Associated with Petroleum Operations in the Former‐Petroecuador‐
Texaco Concession Area, Oriente Region, Ecuador May 2014
Expert Opinion of Suresh H. Moolgavkar, M.D., Ph.D. May 9, 2014
Expert Opinion Of John A. Connor, P.E., P.G., Bcee, Regarding Remediation Activities And
Environmental Conditions In The Former Petroecuador ‐ Texaco Concession, Oriente
Region, Ecuador May 7, 2014
Claimants’ Supplemental Memorial on Track 2, May 9, 2014
Prepared at the request of:
Winston & Strawn LLP
1700 K Street N.W.
Washington DC 20006‐3817
and
The Louis Berger Group, Inc.
412 Mount Kemble Avenue
Morristown, NJ 07962‐1946
Prepared by:
H. Strauss Associates, Inc.
30 Union Avenue
Boston, MA 02130
______________________________________
Harlee S. Strauss, PhD.
November 7, 2014

TABLE OF CONTENTS
1.0 Introduction ....................................................................................................................... 1
1.1 Summary Of Scope Of Retention ................................................................................................. 1
1.2 Summary Of Previous Opinions ................................................................................................... 1
2.0 Response To Claimants’ Critiques Of Risk Assessment .......................................... 3
2.1 Texpet’s Contamination Has Resulted In Both Cancer Risk And Non‐Cancer
Health Hazards Regardless Of Whether The Contamination Is Considered
“Widespread” ............................................................................................................................................... 5
2.2 There Are Current Exposures To Residues Of Crude Oil Released By Texpet,
Although This Is Not A Requirement For A Finding Of Unacceptable Risk ....................... 6
2.3 Exposure Parameters Are Appropriate For The Concession Area ................................ 8
2.3.1 Drinking Water Ingestion ...................................................................................................................... 9
2.3.2 Soil And Sediment Ingestion Rates ................................................................................................. 10
2.3.3 Frequency And Duration Of Bathing .............................................................................................. 13
2.4 TPH Can Be Used To Evaluate Toxicity, Especially Oil Related Toxicity, and Thus
To Show Health Risks ............................................................................................................................ 14
2.4.1 Development Of A Non‐Cancer Dose Response Factor (Reference Dose) For Crude
Oil From The Concession Area .................................................................................................................... 15
2.4.2 Methods For Analyzing TPH ............................................................................................................. 16
2.4.3 Risk Characterization Based On Crude Oil As A Whole ......................................................... 18
2.5 There Are Substantial Non‐Cancer Health Risks From Exposure To Crude Oil .... 19
2.6. There Are Cancer Risks From Crude Oil Exposure ........................................................... 21
2.6.1 Toxicology Studies Show Crude Oil Components Are Mutagenic And Carcinogenic . 22
2.6.2 Risk Of Cancer In The Concession Area Using HHRA Methodology ................................. 23
2.7 Response To Additional Critiques From Claimants’ Experts ....................................... 24
2.7.1 Barium Toxicity Is Evaluated Appropriately ............................................................................. 24
2.7.2 Surface Water Samples Should Not Be Filtered ........................................................................ 25
2.7.3 Exposure Is Evaluated At Appropriate Locations ..................................................................... 25
2.7.4 Exposure To Sediments And To Surface Water Is Evaluated Appropriately ................ 26
2.7.5 Dr. McHugh’s Citation Of His Personal Experience Is Culturally Inappropriate And
An Unreliable Basis To Develop Exposure Parameters In The Concession Area ................... 26
3.0 Supplemental Opinion: Petroleum Contamination Has Reduced Local Food
Resources, Including Farm Animals, Crops, And Fish. The Reduced Availability
Of Home‐Produced Food Has Had An Adverse Impact On The Health Of The Local
Population That Relies On These Resources. .................................................................... 27
3.1 Loss Of Livestock .............................................................................................................................. 27
3.2 Contamination Of Fish Pond At SSF‐13 .................................................................................. 31
3.3 Implications Of Livestock, Fish, Wild Game And Crop Loss .......................................... 31
4.0 Supplemental Opinion: Dr. Moolgavkar Used Highly Flawed Data As The
Basis Of His Cancer Study, Making His Results And Conclusions Unreliable And
Uninformative .............................................................................................................................. 32
November 7, 2014 page i

4.1 Cancer Mortality Data From The Oriente Are Unreliable .............................................. 32
4.2 Dr. Moolgavkar Uses An Inappropriate Measure Of Oil Exposure ............................ 34
Technical Appendix 1: Details Of The Risk Calculations ............................................... 36
Technical Appendix 2: Development Of A Reference Dose For Crude Oil ............... 37
References ..................................................................................................................................... 39
November 7, 2014 page ii

1.0 Introduction
This report responds to comments on my rejoinder expert report dated December 16,
2013, offered by Chevron’s experts McHugh, Moolgavkar, and Connor and by Claimants in
their Supplemental Memorial of May 2014.
I continue to hold the opinions expressed in my February and December 2013 reports and
provide additional evidence to support those opinions in this report, including quantitative
risk assessments of additional well sites investigated by LBG in 2014. I also provide
opinions regarding the adverse impact of petroleum contamination on local food
production and human health, and the unreliability of death certificate data with regard to
cancer deaths in the Concession Area.
1.1 Summary Of Scope Of Retention
Since providing my expert report in December 2013, I have been further retained to: 1)
review additional reports prepared by Chevron’s experts; 2) travel to the Concession Area
to personally view locations of additional field studies and to interview residents near well
sites studied by LBG and health care providers in the Concession Area; 3) prepare
additional baseline human risk assessments using newly collected data; and 4) prepare this
report to respond to issues raised by Chevron’s experts regarding my December 2013
report.
My opinions in this expert report are given to a reasonable degree of scientific probability.
They are based on my education, training, experience, information and data available in the
scientific literature, and information and data about this lawsuit made available to me at
the time these opinions were formulated. They are also based on personal observations
during my visits to the Concession Area including my most recent visit of approximately 10
days in June 2014. If additional information becomes available, I reserve the right to
supplement my opinion to reflect such information.
1.2 Summary Of Previous Opinions
1) The extraction and transport of crude oil from the Napo Concession Area in Ecuador’s
Oriente (“Concession Area”) by Texaco Petroleum (“Texpet”) resulted in the release of
contamination into the environment that, with sufficient exposure, is toxic to humans.
This remains my expert opinion. Chevron’s experts McHugh, Moolgavkar, and Connor
commented on various aspects of my expert report in their May 2014 rebuttal reports.
None of Chevron’s experts contested the existence of contamination sources related to
crude oil or its components. The LBG reports have examined sources and types of
contaminants released during oil well installation and operation, including contamination
attributable solely to Texpet operations. These additional analyses identify petroleum‐related
contaminants and elevated concentrations of barium, a metal associated with
drilling muds.
November 7, 2014 page 1

2) During Texpet’s operations, adults and children residing in the Concession Area were
exposed to crude oil and its residues, produced water, drilling mud, hydrogen sulfide,
diesel emissions, and flares via exposure pathways that result in inhalation, ingestion,
and/or dermal exposures. Some exposure is ongoing at locations where Texpet released
contamination remains in environmental media. Several of the pathways by which
Concession Area residents were exposed to contaminants are not generally included in
exposure assessments in industrialized countries, but are critical to consider based on
the lifestyle and cultural practices in the Oriente. This includes, but is not limited to,
domestic use of water visibly contaminated with oil, walking on local roads that were
coated with crude oil and its residues, and consumption of fish floating (dead) in oil
contaminated water.
This remains my expert opinion. Chevron’s experts McHugh and Moolgavkar did not
dispute the specific exposure pathways listed in my February 2013 report, although they
did dispute whether there is on‐going exposure from these pathways that is attributable
to Texpet and is high enough to constitute a health hazard.
My expert opinion continues to be that exposures originating from Texpet sources pose a
risk to the health of residents in the Concession Area. The basis of this opinion is the
qualitative assessment provided in my original report, strengthened by the quantitative
risk assessment in my December 2013 report, and further strengthened by the additional
data collected in field studies conducted in 2014. My analysis of the non‐cancer hazards of
the most recent data is discussed in Section 2.5. My analysis of cancer risks from crude oil
is set forth in Section 2.6.
3) Adverse effects reported in studies of occupational and community exposures to crude
oil include skin irritation and other skin problems, eye irritation, throat irritation,
headaches, dizziness, psychological problems, perception of poor health, leukemia and
other types of cancer. The adverse effects reported by adults and children in the
Concession Area following exposure to crude oil and its residues are completely
consistent with effects reported from dermal and air exposures in other settings. Other
symptoms, such as stomach problems and diarrhea, are consistent with symptoms of
poisoning following ingestion of petroleum products.
This remains my expert opinion. No Chevron expert has disputed the toxicity of crude oil
and its components. Although Chevron expert Dr. Moolgavkar states that there are no ‘gold
standard’ epidemiological studies proving adverse effects from exposure to crude oil, Dr.
McHugh—who (unlike Dr. Moolgavkar) has a toxicology degree—does not dispute the
clinical and toxicological evidence for health impacts from exposure to crude oil. Dr.
Moolgavkar also claims that his epidemiological study shows there are no excess cancer
risks in the Concession Area. As discussed in Section 4, however, his study is based on
unreliable data and thus is non‐informative.
In her opinion, Dr. Blanca Laffon describes her studies of the immediate and delayed
impacts of exposure to fuel oil from the Prestige oil spill off the coast of Spain on workers
and community members. Dr. Philippe Grandjean addresses the epidemiological issues

raised by Dr. Moolgavkar in his opinion.
4) The patterns, durations, and intensities of exposure in the Concession Area are different
from these aspects of exposure in occupational settings and in general populations of the
industrialized countries in which most epidemiological studies are conducted. As a result
of these differences, comparable emissions or contaminant concentrations will result in
higher exposures and doses of the contaminants to children and adults in the Concession
Area, which, in turn, results in an increased likelihood and severity of adverse effects in
the exposed population.
This remains my expert opinion. My visits to the Oriente region in 2014 further confirmed
my opinion.
5) Toxic contaminants released into the environment during Texpet’s exploration and
production of crude oil resulted in immediate and delayed adverse health effects in
children and adults living in the Concession Area. Some of these exposures are on‐going
and continue to create immediate health effects. The delayed health effects are
continuing to harm residents from previous exposures as well as on‐going exposures.
This remains my expert opinion. This opinion was based, in part, on my quantitative risk
assessment for four sites, as described in my December 2013 report, and is further
confirmed by the additional quantitative assessment provided in this report and the
opinions of Drs. Laffon and Grandjean.
6) Ecuadorian and World Health Organization drinking water standards are exceeded in
the Concession Area
This remains my expert opinion. The basis for this opinion was provided in my December
2013 report.
2.0 Response To Claimants’ Critiques Of Risk Assessment
Claimants and their consultants confuse the concepts of human health risk assessment
(“HHRA”) for regulatory purposes such as cleanup decisions with whether a substance
causes an adverse effect in a specific individual (causation). While exposure assessment
methodology can be used to estimate exposures for regulatory HHRAs and to estimate a
dose to a specified individual to evaluate causation, the evaluations have different
objectives and the details of the calculations differ. HHRAs, such as the ones I have
prepared for this and previous reports, incorporate conservative (health protective)
exposure parameters to evaluate exposure to a hypothetical “reasonably maximally
exposed” (“RME”) individual, defined as “the highest exposure that is reasonably expected
to occur at a site” (US EPA 1989, p. 6‐4). Regulatory HHRAs include evaluations of
exposures due to current and reasonably foreseeable future uses to evaluate whether
remediation is necessary. This was the objective of my December 2013 HHRA: to
determine whether remediation is necessary, examining each well site individually.

My HHRAs are based on a conceptual site model of the Concession Area as shown in the
diagram below.
The current conditions scenario, so‐called because it is currently available to the
hypothetical RME being evaluated, is based on residential exposure to groundwater (where
sites have dug wells), soil, and surface water, which includes drinking, cooking, bathing,
and laundry. Residential use of surface water includes exposure to both water and
sediment, with intake of contaminants by ingestion and dermal contact. There is further
exposure from residues on the laundered clothing.
The future use scenario is based on the same exposures, plus the use of a dug well as a
domestic water supply at sites where there is not currently a dug well. Similar to the
current conditions scenario, this could result in ingestion and dermal exposure to
groundwater.1 Consistent with United States Environmental Protection Agency (“US EPA”)
risk assessment methodology, the evaluation is conducted assuming the same usage
pattern as would occur absent any contamination. For this reason, the reduction in surface
or groundwater use due to rainwater usage (collection barrels shown near the house) is
not included in the evaluation.
The diagram also shows many animals present in the vicinity of the house — e.g., chickens,
ducks, cattle, and dogs. These animals (and children) get into the contaminated sediment
and surface soil, which is very muddy especially during the rainy season, and then track the
soil and sediments onto other surface soils. All but the cattle also enter the residence, again
tracking in soil and sediment where it becomes indoor dust.
Claimants criticize my December 2013 HHRA showing that crude oil residues at four well
sites pose significant risks of adverse health effects to residents under current and future
1 In some groundwater samples, there are volatile compounds at high enough concentrations that inhalation
exposure could also pose a risk, but this has not been quantified.

conditions. Claimants contend that: 1) contamination is not “widespread” and thus poses
no risk to the population; 2) there are no “actual” exposures; 3) I used exposure
parameters that are too high, and thus grossly overestimate exposure and risk; and 4)
there are no health risks from TPH.
These critiques are all baseless, and each is addressed in turn in sections 2.1 through 2.4.
In section 2.5, I address the non‐cancer health risks of exposure to oil. In section 2.6, I
address the cancer risk from exposure to oil. And in section 2.7, I address miscellaneous
other criticisms from Claimants’ experts.
2.1 Texpet’s Contamination Has Resulted In Both Cancer Risk And Non‐Cancer Health
Hazards Regardless Of Whether The Contamination Is Considered “Widespread”
In a regulatory HHRA, human health risks are evaluated on an individual, not a population,
basis. Thus, whether or not contamination is widespread is irrelevant to my assessment of
whether cancer risks and non‐cancer hazards exist at the locations examined. An HHRA,
identifies whether people can potentially come into contact with the contamination under
present or future conditions, and then evaluates health risks based on that contact. Of
course, the more “widespread” the contamination, the higher the number of children and
adults who may be at risk.
There are significant risks to human health for current and/or future exposures, as
evaluated by accepted HHRA methodology, at all four locations evaluated in my December
2013 rejoinder report. The additional sites evaluated in this report also pose significant
risks of adverse health effects under current and/or future conditions. For example,
additional sampling at LA02, a previously evaluated site, shows oil contamination in the
surface soil that serves as the front patio where the family spends much of its time, on the
floors of the living area and kitchen, and on a plastic toy used by young children.
Weathered residues of crude oil are also visible adjacent to the back of the house, and
additional residues continue to surface due to erosion and land use. These new data
provide a definitive link between environmental contamination in sediments and/or pit
soils, and everyday locations of human exposure. Section 2.2 includes additional
information regarding these exposures.
While not evaluated in my HHRA, there is ample evidence of past exposures to Texpet‐released
petroleum related contaminants at these and other sites. The evidence includes:
1) Chevron interviews, audit reports and aerial photography showing the existence of open
pits2 and people living in close proximity to them under living conditions similar to those
evaluated in the current HHRA; 2) the decision by residents to purchase water for all
domestic uses due to past contamination (e.g., AG06, SSF 25, SSF43); and 3) interview
information and signed affidavits regarding lost farm animals at many of the sites
evaluated (e.g., AG02, SSF13, SSF34, SSF43).
2 Clickable database; LBG November 2014 Expert Report, section 2; LBG 2013 Expert Report, p. 23.

2.2 There Are Current Exposures To Residues Of Crude Oil Released By Texpet,
Although This Is Not A Requirement For A Finding Of Unacceptable Risk
The Claimants’ critique that there are no actual exposures in the Concession Area and thus
no risk is wrong for two reasons: 1) there are residents who have current exposure to
petroleum residues, including from petroleum residues that could have originated only
from Texpet activities, and 2) the determinant for whether remediation is necessary is
based on the highest exposure reasonably expected to occur given the current and future
exposure pathways to an individual, referred to in an HHRA as an RME individual.3 In fact,
under ASTM guidance4 cited by Claimants’ experts, current exposure would be identified as
an immediate threat and trigger response actions to abate the exposure.
Based on data from the 2013 and 2014 site investigations conducted by LBG, my personal
observations and those of LBG field personnel, and witness interviews, there are current,
on‐going daily exposures of children and/or adults to petroleum contaminants at multiple
well sites including:
 AG02 – Children and adults from approximately 6 residences use the contaminated
stream for drinking, cooking, bathing, and washing5 (see photo section 2.3.3).
 AG06 – The farmer/landowner reports that his family uses rainwater and
purchases municipal water for all domestic uses, but he uses the contaminated
stream for drinking water while working in the field. He estimates that he drinks
4‐5 liters of stream water on hot days when he is working in his fields near the
stream. His cows also drink from this stream, come into contact with sediments,
and become ill.
 LA02 –The adults and children living in the house adjacent to the platform come
into contact with petroleum contamination throughout the day, every day.
Sampling conducted in June 2014 detected crude‐oil related contamination on the
floors in the kitchen area and living area (separate buildings), and on a child’s
plastic sit‐on pony. The surface soil of the front patio has crude oil residues as does
the soil in the back of the house where asphalt chunks are embedded. Sampling in
the summer of 2013 identified contaminated sediment and surface water in the
wetlands area immediately downhill from the house. The surface water is an
abandoned water supply that continues to be used by farm animals such as mature
chickens and ducks and that has no barrier to access by young children.
3 US EPA, 1989. Risk Assessment Guidance for Superfund; US EPA 1991. Role of Baseline HHRA in
Remediation Decisions. US EPA 1989 p. 6‐4: “Actions at Superfund sites should be based on an estimate of the
reasonable maximum exposure (RME) expected to occur under both current and future land‐use conditions.
The reasonable maximum exposure is defined here as the highest exposure that is reasonably expected to
occur at a site. RMEs are estimated for individual pathways. If a population is exposed via more than one
pathway, the combination of exposures across pathways also must represent an RME.”
4 ASTM E1739‐95 Standard Guide for Risk‐Based Corrective Action Applied at Petroleum Release Sites., p. 7
(Table 1). ASTM International develops voluntary standards used globally.
5 See also Jose Guamán witness statement.

 LA16 – An extended family living in two houses uses petroleum‐contaminated
water from a shallow dug well for drinking, cooking, bathing, and laundry. The
family pours water over their young children several times a day, and more
frequently when it is hot (see photo section 2.3.3). A house completed in the
summer of 2014 has a new shallow dug well that appears to be their water supply.
This well is also contaminated with petroleum.
 SSF13 – The residents of this farm obtain their drinking water from a stream
catchment area. A sample collected in the same stream immediately downstream
from the drinking water area revealed petroleum contamination. This water is
used for drinking, cooking, bathing, laundry, and water for farm animals such as
chickens and ducks. The chickens and ducks are caged to prevent them from
coming into contact with contaminated sediments and highly contaminated surface
soil in a former pit, although both the sediments and soil are freely accessible to
children (and adults) and cattle raised on the property. A tilapia pond on the farm
which no longer supports fish has crude oil related contaminants in the water
sample tested by LBG.
 SSF25 – There are two sets of residents living near this well site. One residence,
apparently a rental facility, is a house on stilts adjacent to a contaminated stream.
There is evidence that the occupants of this residence used the contaminated
stream in the past.6 While there is now a metered water supply piped in from the
dug well in LaVictoria, it is not always available. As of June 2014, the stream
continues to remain readily available for use by the occupants, two children and
two adults, when the municipal water is unavailable. The owner of the land lives in
a house adjacent to the road with his wife and three children (with another on the
way as of June 2014). This household also relies on water piped in from LaVictoria.
It is not clear what they use when this water is unavailable. The landowner reports
that in the Spring of 2014 chickens, ducks, and at least one cow died after
wandering into a contaminated swampy area behind his house.
 SSF34 – Agricultural workers were observed in and near an area of contaminated
soil. Crops are not growing well in the contaminated area; the owner said they
were cutting down the poorly growing papayas to try cacao.
In addition to these current exposures, there is ample evidence, based on interviews and
observations, that residents in the Concession Area try to avoid exposure to contaminated
soil, water, and sediment and have had to abandon previously used resources to do so.
Examples include:
 AG06 – A family at this site replaced previously used surface water resources with
rainwater and a dug well, supplemented with purchased municipal water delivered
by tanker truck every one to four weeks. The family no longer uses the stream for
drinking, cooking, bathing, swimming, or laundry. The family also provides water
for their chickens and pets, which they reported were harmed by drinking and
standing in the stream water.
6 This use was described and documented in my December 2013 report.

 LA02 – This family uses rainwater and a well some distance away from their home
to avoid using the contaminated stream adjacent to their house that had been a
drinking water source (and that the mother had used while growing up at this
location). The mother washes the laundry in the stream down the road near her
parents’ house instead of the more convenient, but highly contaminated, area of the
stream adjacent to her house. The father reports that he teaches his children not to
play in the contaminated sediment, and he has built a cage to prevent very young
chickens and ducks from getting into the contaminated sediments where many have
died. The father covered a petroleum contaminated pit on his property so that his
adult chickens, ducks and geese would stop falling into it and dying.
 SSF13 – The family on this farm cages its ducks and chickens to prevent them from
dying as a result of contact with contaminated sediment and water.
 SSF25 – The residents of both houses at this site purchase municipal water to
replace previously used surface water. However, because the municipal water is not
always available, they may continue to use surface water as well.
 SSF43 – The residents no longer use their drinking water well, which is
contaminated with petroleum, because they said the odor of petroleum was
noticeable.7 The loss of this resource has forced this family to pay for tanker trucks
to deliver community water. This family also prohibits their children from having
pets because it is too sad when the animals die after entering the contaminated
wetlands area. The family no longer maintains livestock because of their inability to
keep them out of the contaminated area.
2.3 Exposure Parameters Are Appropriate For The Concession Area
In a regulatory HHRA, exposure is calculated for a hypothetical person, and is intended to
represent an RME. The calculation incorporates several parameters such as: how
frequently people are exposed, how long they are exposed, how much water people drink,
and how much soil/sediment they ingest, among others. The exposure parameters I used
in my December 2013 HHRA are appropriate for the rural areas of the Concession Area,
with the intention of calculating an RME under current or future conditions. In several
cases, the exposure parameters are higher than are used by the US EPA because of the
differences in climate and in the daily activities of the subsistence lifestyle maintained by
the rural residents living near Concession Area well sites. The exposure parameters are
therefore not overly conservative and they do not overestimate risk, as Claimants’
consultants allege. In fact, as I pointed out in my December 2013 opinion, many exposure
pathways were not evaluated due to lack of data. As a result, my HHRA more likely reflects
an underestimate, rather than an overestimate, of the risk of harm to the residents.
The use of site‐specific data over standardized assumptions (default values) has been part
of US EPA and other agency risk assessment policies for decades. For example, a widely
used US EPA document states:
7 This well was tested by LBG in June 2014. The results can be found in the LBG November 2014 Expert
Report, Appendix A Site Investigation and Data Summary Report.

“EPA has made a policy decision to use, wherever appropriate,
standardized assumptions, equations, and values in the human health
evaluation to achieve the goal of streamlined assessment. This approach
has the added benefit of making human health evaluation easier to review,
easier to understand, and more consistent from site to site. Developing
unique exposure assumptions or non‐standard methods of risk
assessment should not be necessary for most sites. Where justified by site‐specific
data or by changes in knowledge over time, however, non‐standard
methods and assumptions may be used.”8
The hot and humid climate and subsistence lifestyle of residents exposed to contamination
at the well sites being evaluated provide clear justification for the use of non‐standard
exposure parameters. The sections below explain what site‐specific exposure parameters
were used and why they are appropriate to evaluate risk in the Concession Area.
2.3.1 Drinking Water Ingestion
The drinking water ingestion rate used in my HHRAs is appropriate for the climate in the
Oriente and the daily activities of the rural residents in this area. The basis for the use of
7.5 liters/day in the Concession Area was provided in Appendix A of my December 2013
Rejoinder Report. This drinking water intake rate is far more appropriate for the
Concession Area residents evaluated than the 2 liters/day consumed by an office worker in
the US, as advocated by the Claimants and their consultants.9
Additional support for this water intake level is provided by US guidance for agricultural
workers working in hot weather, conditions consistent with those of the rural residents of
the Concession Area. The US Occupational Safety and Health Administration (“OSHA”)
recommends 1 liter/hour fluid consumption during working hours when the heat index is
greater than 91oF. 10 The heat index frequently reaches this level in the Oriente . The State
of California also requires that employers provide at least 1 L/hour potable water for each
outdoor worker to prevent heat stress.11
These drinking water rates for outdoor and agricultural workers are consistent with, or
even suggest an underestimation of, the 7.5 liters/day intake used in my HHRAs, which was
based on, among other things, US Army guidance for water intake for refugees in a hot
8 US EPA 1989, pp. 3‐1 to 3‐2.
9 US EPA increased the default drinking water rate for adults from 2 to 2.5 L/day in February 2014. US EPA
Feb 2014 a, b OSWER Directive 9200.1‐120.
10 OSHA (Occupational Safety and Administration) Heat Index and Protective Measures (accessed on OSHA
website Oct 2014). The heat index is a combination of temperature and humidity and reflects the “felt
temperature.”
11 California Department of Industrial Relations Heat Illness Prevention Standard Title8 CCR3395:
http://www.dir.ca.gov/Title8/3395.html.

climate. Higher activity levels, such as those involved in farming, require higher water
consumption (separate from, and in addition to, hot climate considerations). Interviews
conducted with Concession Area residents in June 2014 support water intake levels of at
least 7.5 liters each day. For example, the owner of the farm near AG06 said he drinks 4‐5
liters of water (from the stream) while in the field on sunny days, less on days that are not
sunny. This intake does not include water consumption while at home or water used in
food preparation.
I am aware of no data or occupation recommendations for drinking water intake for
children in a hot and humid climate. My HHRA used a valid methodology based on
physiology to estimate a child’s water consumption rate compared to an adult’s
consumption rate. To discredit this evaluation, Dr. McHugh referenced an irrelevant case
report by Bruce and Kleigman (1997) that describes two infants in a temperate/chilly
climate (Wisconsin, US) whose very poor, young mothers fed them bottled drinking water
to supplement their infant formula. The result was an electrolyte imbalance. As noted in
my earlier reports, living in a hot climate requires a higher fluid intake to offset the loss of
water through sweat to remain cool. Dr. McHugh's citation provides no information
regarding appropriate drinking water intake for infants and young children in the
Concession Area. In addition, Dr. McHugh provides no evidence to support his contention
that breastfeeding is the source of fluids for infants and young children. UNICEF data from
2004 show that about 40% of Ecuadorian women breastfeed exclusively for 6 months, an
increase from 1999.12 The Ministry of Public Health (Ecuador) summarizes data from
2008 showing that, in rural zones, the average duration of exclusive breastfeeding is 3.6
months for the 53.9% of women who breastfeed exclusively.13 Moreover, even for
breastfed infants, hydrophobic components of oil such as PAHs and other polycyclic
aromatic compounds are excreted in breast milk and thus passed on to breastfeeding
infants leading to higher exposure than estimated in the HHRAs.14
2.3.2 Soil And Sediment Ingestion Rates
There have been many studies of how much soil is ingested during daily activities in the US,
Europe, and elsewhere.15 Soil is typically ingested when it gets on hands or other objects
and the objects get put into the mouth. In most cases, soil ingestion is higher in young
children than adults because children have more hand‐to‐mouth and object‐to‐mouth
activities. Both children and adults ingest soil that gets into the house and becomes part of
indoor dust, settling on food or indoor objects such as toys or glasses. Soil can also be
ingested on fruits or vegetables that are not thoroughly washed.
12 UNICEF data http://www.indexmundi.com/facts/ecuador/exclusive‐breastfeeding.
13 Ministerio de Salud Pública del Ecuador Funbbasic/Ibfan. May 2009. World Breastfeeding Trends Initiative.
National Report.
14 Del Bubba et al 2005. PAHs and fat content in breast milk. Annal di Chimica 95: 629‐642. OEHHA 2014.
Table 5.5 p. 5‐22.
15 US EPA 2011. Exposure Factors Handbook. EPA/600/R‐09/052F.

The amount of soil ingested each day (i.e., the ingestion rate) depends on, among other
things, the frequency of hand to mouth activity, and the amount of dirt on hands when
these activities occur. The amount of indoor dust also plays a role.
Sediment ingestion occurs for the same reasons as soil ingestion, although it has been less
well studied.16 The Concession Area residents are exposed to sediment in a similar way as
soil, including tracking in and becoming part of indoor dust. The common practice in US
EPA‐type HHRAs is to set the sediment ingestion rate to the same value as the residential
soil ingestion rate.
Examples at LA02 of why soil and sediment ingestion occurs
play with
dog, dog
tracks soil
and sediment
into house
Patio LA02
chicken
tracks in soil
and sediment
Living Space LA02
dust from
soil and
sediment on
food (potatos
in chair)
Kitchen LA02
Soil and sediment ingestion rates are no doubt higher in the rural parts of the Concession
Area than is typical in the US for several reasons including: 1) wet and oil‐contaminated
soil17 adheres to hands and other objects more than dry soil, 2) people spend most of their
day outdoors (resulting in a higher ingestion rate),18 and 3) soil and sediment are regularly
tracked into homes on a daily basis due to the outdoor lifestyle and the presence of farm
animals indoors.
16 From the point of view of an exposure assessment, the difference between soil and sediment is the location
(i.e., sediment is located in waterways or wetlands) and that sediment is wet, which means it adheres to skin
in a thicker layer than dry soil.
17 US EPA 2011, Exposure Factors Handbook EPA/600/R‐09/052F at pp. 7‐20.
18 Van Wijnen et al. 1990. Cited in US EPA 2011 ibid at pp. 5‐10.

My 2013 HHRA evaluated sediment ingestion but not soil ingestion because surface soil
sampling was not included in LBG’s 2013 sampling program. For the reasons just
described, I used soil ingestion rates to analyze the sediment ingestion. For young children,
I used a rate of 200 mg/day, which is the USEPA high end ingestion default rate.19 For
adults, I used an ingestion rate of 100 mg/day, based on the USEPA high end default rate
for adult residential exposure to soil.20
Dr. McHugh claimed that my 2013 HHRA overstated the ingestion rate for sediments. But
the methodology applied in my HHRA is identical to that which would be applied at a
hazardous waste site in the US where soil ingestion rates are often substituted for sediment
ingestion rates. Moreover, in the Concession Area, the indoor dust component of the
ingestion rate is likely to be derived, in part, from sediment tracked into the house by
people and animals. Thus, because the conditions in the Concession Area result in a higher
ingestion of soil and sediment than is anticipated and/or provided for in the US‐based
studies on which this ingestion rate is based, 200 mg/day for children and 100 mg/day for
adults should be considered to be a moderate estimate of soil and sediment ingestion in the
Concession, not an overestimate.
LBG’s 2014 sampling program included both sediment and surface (or shallow) soil. In my
current HHRA, I evaluated sediment data in the same manner as my 2013 report (200
mg/day for children and 100 mg/day for adults) using the same HHRA methodology
described in my 2013 report. For soil, I used the same 200 mg/day for children and 100
mg/day for adults for residential exposure. For certain sites, I used a 200 mg/day exposure
rate for adults because their exposure is agricultural in nature.
The amount of soil ingested by adults in agricultural and other high soil contact settings is
higher than in residential areas, which is well known and acknowledged by US industry.
For example, General Electric suggested a soil ingestion rate of 136 mg/day for utility
workers and agricultural workers in comments on a 2004 HHRA prepared by the US EPA.21
More recently, the California Environmental Protection Agency published a high end soil
ingestion estimate for adults of 210 mg/day.22
Like their children, adults in the Concession Area will ingest more soil than an adult office
or factory worker in the US, and a high end soil ingestion rate based on data collected in the
US and Europe will be closer to a central tendency ingestion rate in the Concession Area
residences and farms near well sites.
19 In the US, studies of soil ingestion rates – which are usually conducted in urban and suburban settings
where much time is spent indoors – show that rates vary among the participating individuals. EPA
summarizes high end and central tendency estimates of these exposures c.f. EPA 2011 op. cit. Table 5‐1. p. 5‐
5, and generally recommends the use of the high end rates in HHRA calculations for the RME.
20 US EPA 2014b.
21 Excerpt from a response by General Electric to a US EPA risk assessment for the Housatonic River in
Massachusetts.
22 CA EPA (OEHHA) Draft Hot Spots Program Guidance Manual) September 2014.

Finally, Dr. McHugh's unsupported assertion that stream sediments are constantly covered
with water shows his unfamiliarity with the seasonality of the water levels in the
Concession Area, and the extent of sediment contamination. The contention that the
contaminated sediments are always buried under clean sediments is also false. All of the
sediment samples collected in the 2014 sampling program and most of the sediments
collected in 2013 (including all the samples included in the risk calculation) are surface and
shallow sediments. These sediments are or easily could be encountered by residents, e.g.,
as they stand in the streams to wash clothing, or by animals drinking stream water, and
then tracked into houses — and they are contaminated with petroleum.23
2.3.3 Frequency And Duration Of Bathing
I used US EPA default values for bathing frequency and duration in my 2013 HHRA.
Additional information was collected in June 2014 from observation and interview data in
the Concession Area. Bathing is used for both cleaning and heat relief. Mothers in rural
areas relevant to the HHRA reported bathing their children at least once each day; several
reported bathing their children multiple times per day, including the mother of young
children at LA16. As shown below, bathing at LA16 means using a bucket to pour water
over the child. This process is repeated many times per bathing event adding to the total
amount of time the water remains on the skin. In other locations, children are immersed in
water. For example, at AG02 (shown below), children and adults bathe and wash laundry
while immersed in a stream.
bathing and washing at LA16 bathing and washing at AG02
The duration of bathing is variable and less well known. My HHRA relied on US EPA
guidance in effect when the risk assessment was prepared, one hour for young children and
35 minutes for adults and children over 6. In February 2014, the US EPA changed its
recommendation for default values based on more recent data.24 The young child bathing
23 LBG December 2013 Rejoinder Report, Appendix B Site Investigation and Data Summary Report and LBG
November 2014 Expert Report, Appendix A Site Investigation and Data Summary Report.
24 US EPA 2014 a, b OSWER Directive 9200.1‐120 dated February 6, 2014.

duration was reduced to 32 minutes and the older child and adult bathing duration was
increased to 43 minutes. Use of US data may underestimate the typical length of dermal
contact with water because Concession Area residents use the same surface water for
bathing, swimming, and laundry, and the climate is hotter and more humid than typical in
the US.
In response to Chevron’s criticisms, I calculated cancer risk and non‐cancer hazards based
on both 30 minute and 60 minute duration bathing for young children. The duration of the
bathing made little to no difference in the risk calculations, and no difference in conclusions
based on exceedance of a benchmark because dermal exposure to water is just one of
several contributors to the overall risk at most of the well sites. For the risk calculations
reported below, I used the revised US EPA recommendations.
2.4 TPH Can Be Used To Evaluate Toxicity, Especially Oil Related Toxicity, and Thus To
Show Health Risks
It is undisputed that Dr. McHugh did not evaluate health risks from TPH in his risk
assessments. In part, he argued that it was impossible to evaluate risks from TPH. In this
section, I provide a methodology, explained below, to evaluate health risks associated with
exposure to crude oil and its residues using TPH as a measure of concentration and
petroleum industry generated toxicity data for crude oil. I further show that TPH
measured by total extractable material (TEM) method provides the most appropriate
measure of TPH concentration to use in this evaluation.
The four step methodology for conducting an HHRA, applied here, was described in both of
my previous expert reports: 1) hazard identification; 2) dose‐response assessment; 3)
exposure assessment; and 4) risk characterization.25
The goal is to characterize the risk of health effects to determine if cleanup is warranted.
The first step to achieving this goal is to identify the hazard. In the Concession Area, the
hazard is crude oil and its residues, hazards that have been described based on clinical
studies, toxicology studies, and epidemiological studies. The dose response assessment
is usually based on toxicity (animal) testing. The American Petroleum Institute (“API”)
(2011) has summarized toxicity tests of crude oil for a number of adverse effects. API has
also developed models to predict the adverse responses at particular doses (benchmark
doses) of different crude oils; these are necessary for a quantitative dose‐response
assessment. The exposure assessment is the estimation of the dose that reaches a
hypothetical RME person. The exposure assessment includes the analytical data collected
at the location being evaluated (in this case measures of TPH at the various well sites) and
various exposure parameters such as those discussed in earlier sections of this report.
Information from the dose‐response assessment and exposure assessment are combined to
characterize risk.
25 Strauss, Feb 2013 Section 2.3.2 pp. 12‐17 and Strauss Dec 2013 Appendix A.

The non‐cancer and cancer assessments are conducted separately. The results are called
the hazard index (HI) and excess lifetime cancer risk (ELCR), respectively. These results
are compared with regulatory benchmarks, which are often an HI of 1 and an ELCR in the
range of 10‐4 to 10‐6 (one in ten thousand to one in a million). If the HI is higher than one,
and the ELCR within or higher than the cancer risk range, further evaluation and often
remediation are required.
2.4.1 Development Of A Non‐Cancer Dose Response Factor (Reference Dose) For Crude Oil
From The Concession Area
The API, as part of its submission to the US EPA High Production Volume program for crude
oil, provided the results of its toxicity testing program for various crude oils.26 The testing
included skin painting studies in which two crude oils, one heavy and one light, were
applied to the backs of rats for 90 days, and the adverse effects evaluated. Both crude oils
caused skin changes (hyperplasia and hyperkeratosis) associated with skin cell
proliferation (pre‐cancer), irritation, and inflammation. Adverse effects on internal organs
were also observed, which shows that toxic components of the oils were absorbed through
the skin and reached internal organs. The immune system (thymus), the endocrine system
(thyroid), the liver, and bone marrow (manifesting as aberrant hematology including
reduced red blood cells and platelet counts) were all adversely affected. Reduced body
weight gain, a reflection of slower growth of the young animals used in the experiment and
a general indicator of toxicity, was also observed. Skin irritation and thyroid effects
(hypertrophy and hyperplasia, potentially a precancerous condition) were observed even
at the lowest dose tested.27
Similar skin painting studies were conducted using pregnant rats to determine the impact
of crude oil on the developing fetus and young offspring. Crude oil was painted on the
backs of pregnant rats from zero to 19 days of pregnancy. Even this short dosing period
(20 days vs. 90 days, above) resulted in the adverse effects just described – skin irritation,
immune system effects, liver changes – on the pregnant rats. Observed pre‐natal and post‐natal
effects included increased in utero death, delayed ossification (skeleton formation),
decreased pup body weight, and decreased pup survival.28
As discussed in both of my previous reports, different crude oils have different toxic
potencies, and API has summarized data showing that crude oil’s (and that of other
petroleum products) potency for cancer, birth defects, thyroid effects, blood effects and
immune effects can be predicted by the quantity of the fraction of crude oil known as 3‐7
26 API 2011. Cited and provided in my previous opinions.
27 API 2011. p. 45. These studies were also discussed in my February 2013 expert opinion (p. 41‐42). The
expert report of Dr. Blanca Laffon, submitted concurrently with this one, discusses health effects experienced
by oil cleanup workers. Many are similar to those observed in the toxicity tests.
28 API 2011 pp. 51‐54. These studies were also discussed in my February 2013 expert opinion (p. 42) and my
December 2013 rejoinder opinion (pp. 51‐52).

ring PACs,29 although these are not the only toxic components of crude oil. Skin irritation is
primarily due to an entirely different component of crude oil; and some aromatic
compounds in crude oil, such as benzene, isopropyl benzene (cumene), naphthalene, and 2‐
methylnaphthalene are carcinogenic even though they have 1 or 2 aromatic rings.
Based on the toxicity data from skin painting tests, API calculated doses at which 10% of
the animals are predicted to suffer adverse effects.30 These are known as benchmark doses
or BMD10. API also developed a method for extrapolating the toxicity of known crude oils
to untested crude oils based on the amount of 3‐7 ring PACs in crude oils of untested
toxicity. To quantify the toxicity of the untested oils, API calculated predicted benchmark
doses, denoted PDR10, using the 3‐7 ring PAC concentration of each crude oil as the basis of
the prediction. The PDR10s of more than 40 untested crude oils, along with their API
gravity were in their submission to the US EPA.
Benchmark doses such as the PDR10 calculated by API can be converted to reference doses
(RfDs), which are the toxicity factor used in the dose response assessment. The conversion
is the application of numerical factors to adjust for the uncertainty, variability, and
inadequacies of the benchmark dose. These factors include:
 variability in responses (e.g., one human to another),
 uncertainty of predicting toxicity in humans based on animal data,
 conditions of the test vs. applicable conditions (e.g., 90 day vs. lifetime exposure,
oral vs. dermal exposure),
 whether the benchmark dose is a no observed effect level, and
 quality and completeness of available toxicity data.
Following US EPA guidance for development of reference doses31, I used a factor of 3000 to
convert the PDR10 to a dermal reference dose. The dermal reference dose was the basis of
an oral reference dose. I calculated a dermal reference dose of 0.03 mg/kg‐day and an oral
reference dose of 0.004 mg/kg‐day for crude oil of similar API gravity to that in the
Concession Area. Technical Appendix 2 provides details of my derivation of these doses.
2.4.2 Methods For Analyzing TPH
Measuring the concentration of oil in the environment is a difficult task as crude oil is a
complex mixture with many different compounds with different chemical and toxicological
properties. Sensory approaches such as observation of floating oil or sheen, odor, and taste
are indicative of the presence of oil, and the API and ASTM recommend cleanup when
observed to protect animal and human health.32
29 PACs are polycyclic aromatic compounds. This fraction includes polycyclic aromatic hydrocarbons (PAHs)
as well as toxic compounds that also contain nitrogen, sulfur and oxygen in their rings or attached to the
rings.
30 API 2011 p. 46.
31 US EPA 2002. A review of the reference dose and reference concentration processes. EPA/630/P‐02/002F.
32 API 2004 (Livestock); ASTM E1739‐95 (human health, sensitive ecological receptors).

There are many methods to quantify how much oil, or which components of oil, are
present. Each gives a different result from the same initial sample, depending on factors
that include the portion of the oil mixture targeted for analysis, sample preparation,
detection methodology, potential interferences, and many others. LBG utilized several
methods to quantify oil residues, commonly referred to as TPH (total petroleum
hydrocarbons), in the June 2014 field program:33
 Method 8015M: This method yields fractions labeled as Gasoline Range Organics
(GRO), Diesel Range Organics (DRO), extended DRO, and heavy DRO. Each fraction
has a characteristic carbon range, and aromatic and aliphatic hydrocarbons are
measured together. The DRO and extended DRO fractions include the toxic 3‐7 ring
PAC fraction, although some would be lost due to the solvent used in sample
preparation. The GRO fraction has the 1‐2 ring compounds and is appropriately
evaluated by comparison to gasoline.
 Massachusetts Method VPH/EPH: This method yields fractions with specified
carbon ranges; aromatic and aliphatic hydrocarbons are reported separately. The
aromatic fractions C11‐C22 include the toxic 3‐7 ring PAC fraction, although some
would be lost due to the solvent used for sample preparation. The VPH aromatic
fraction contains the carcinogenic 1‐2 ring compounds.
 Texas Method TX1005: This method yields various fractions of characteristic
carbon range with the aromatic and aliphatic combined. Some of the toxic 3‐7 ring
PAC fraction would be lost due to the solvent used for sample preparation.
 Total Extractable Material (TEM) Method: This method measures the entire
mass of materials using a solvent (dichloromethane) that dissolves the toxic 3‐7 ring
PAC fraction, allowing it to be measured. The results combine all carbon ranges and
aromatic and aliphatic hydrocarbons.
The following chart shows graphically the ranges of crude oil captured by each analytical
method. As can be seen, the TEM method is the most complete, capturing the most
fractions of oil.
33 LBG November 2014 Expert Report. Short November 7 2014, Supplementary Memorial Expert Report.

The fractions detected by the first three methods can be summed to give a single TPH
number for each sample analyzed, although as noted above, these summations still miss
part of the oil components in the original mixture including some of the toxic 3‐7 ring PACs
and heavier components. Most of the crude oil components missed in the summation are
captured in the TEM Method. As a result, TPH measured by the TEM method always gives a
more complete, and thus higher, result than the other three. Detailed comparisons of TPH
concentrations from TEM and Method 8015 show that TEM concentrations are
approximately five times higher.34
2.4.3 Risk Characterization Based On Crude Oil As A Whole
The health risk from crude oil can be evaluated several ways. US EPA guidance for the
evaluation of mixtures35 presents a hierarchy of approaches, with the preferred approaches
being evaluated based on the mixture itself or a sufficiently similar mixture. The oil and gas
industry also recommends this approach.36 Because toxicity data for whole mixtures are
usually lacking, a less preferred but more commonly used approach is to evaluate fractions
of the mixture separately using a toxicity value for each fraction based on one individual
component of that fraction. This method was used in my previous HHRA based on Method
8015M data and Massachusetts VPH/EPH data.
34 Short Expert Report November 2014 section 4.1; LBG Expert Report November 2014 Appendix C2.
35 US EPA 1986. Guidelines for the Health Risk Assessment of Chemical Mixtures. EPA/630/R‐98/002.; US
EPA 2000. Supplementary Guidance for Conducting Health Risk Assessment of Chemical Mixtures.
EPA/630/R‐00/002.
36 c.f., IPIECA 2010 Globally Harmonized System for Petroleum Substances. Version 1.

For crude oil, the non‐cancer hazard can be evaluated using the more preferred whole
mixtures approach based on the quantitative dose response factor described in Section
2.1.4 and an analysis of TPH. In my opinion, the TEM method is the best basis for this
whole oil TPH analysis because it includes almost all of the components in crude oil, and
most closely approximates the measurement used in the toxicity tests (mass of crude oil).
In other words, TEM is the best measure for an “apples to apples” comparison of the dose.
2.5 There Are Substantial Non‐Cancer Health Risks From Exposure To Crude Oil
For this HHRA, I calculated non‐cancer hazard indices (HIs) using both the fraction
approach used in my December 2013 HHRA and the whole mixture approach described
above (section 2.4). I calculated exposure using the same equations as in my previous
HHRA, although the duration of bathing was changed, as described in section 2.3.3 above.
In addition, my new HHRA includes exposures to surface soil, as these data are available
from LBG’s 2014 testing but were not available from LBG’s 2013 testing. Soil ingestion
rates were described in section 2.3.2. Additional details of the exposure calculations are
provided in Technical Appendix 1. The calculation of a reference dose from the API derived
benchmark doses is provided in Technical Appendix 2.
The chart below summarizes the non‐cancer hazards (HIs) at six of the well sites
investigated by LBG in 2014: AG06, LA02, LA16, SSF13, SSF34, and SSF43. I evaluated
several exposure pathways at five of the sites and only a former use pathway at the sixth
(SSF43). The second column lists the type of exposure pathway and whether the exposure
is a past, current, or future use. The columns labeled VPH/EPH fraction and 8015M
fraction give the HIs based on an evaluation of the toxicity of each fraction, the method
used in my December 2013 HHRA. The next three columns provide the HIs using the whole
mixture approach, namely the concentrations in all the fractions obtained using VPH/EPH,
8015M, or TX1005 are summed to obtain the concentration of petroleum hydrocarbons for
that specific method. This total is then used in conjunction with the RfD for Oriente crude
oil described in Section 2.4.1 and Technical Appendix 2. The final column of the chart
below provides the HI calculated by what is, in my opinion, the most appropriate method
for evaluating the risk, namely using oil concentrations measured by TEM and the RfD for
Oriente crude.

The chart highlights the HIs above 1, the point at which harm may occur. HIs above 1 but
less than 10 are highlighted in pink, those between 10 and 99 are highlighted in orange,
and those above 100 in red.
The TEM‐based whole mixture analysis results in the highest HIs, as expected. All methods
result in an HI above 1 for at least three well sites. Non‐cancer hazard was identified at all
six site examined. Exposure pathways at AG06, LA02, and SSF34 had HIs greater than 100,

which means that the doses are approaching the range in which adverse effects were
observed in the toxicology studies.
2.6. There Are Cancer Risks From Crude Oil Exposure
Dr. Moolgavkar continues to state that there is no evidence that exposure to oil has caused
any harm, including specifically, cancer. However, Dr. Blanca Laffon has filed concurrently
with this report a report detailing her findings regarding oil’s genotoxic effects, which show
the cancer risk of oil. In addition, Dr. Moolgavkar’s opinion contradicts petroleum industry
findings and reports that indicate that dermal contact with crude oil is associated with,
among other things, skin cancer, and immune dysfunction.
The worldwide petroleum industry has compiled toxicity data on crude oil to provide to US
and European regulatory programs, such as the High Production Volume program in the US
and the REACH program in the EU. The focus of industry studies is on dermal exposure.
The diagram below, taken from a report published by CONCAWE37, an industry
organization, shows that repeated exposures, such as those experienced by people in the
Concession Area, can result in dermatitis, and skin tumors (cancer), and other health
effects that require quantitative risk assessment, such as that presented in section 2.5.
Figure 6 Health risk assessment of dermal exposure to petroleum
hydrocarbons
37 CONCAWE (Conservation of Clean Air and Water in Europe,) is the oil and gas companies’ European
association for environment, health and safety 2010. Review of dermal effects and uptake of petroleum
hydrocarbons. Report no. 5/10.

Source: CONCAWE 2010, p. 60
CONCAWE38 2010 (p. 59) also points out one reason why the harm increases with repeated
exposures and may produce skin cancer:
“In addition to the irritation effects of petroleum hydrocarbons, the skin
barrier function may be affected following repeated contact, making the
skin more susceptible to other irritants, sensitizing agents, and bacteria
and also enhance the dermal penetration of other substances.
Furthermore, there is increasing evidence that severe, dermal irritation
induced by long‐term or repeated exposure to certain hydrocarbons can
contribute to the progression‐promotion effect and the development of
skin tumours.”
2.6.1 Toxicology Studies Show Crude Oil Components Are Mutagenic And Carcinogenic
The PAC fraction of oil (which includes PAHs) is mutagenic in standard toxicity tests
including the well‐known Ames assay; crude oils are carcinogenic after dermal application
to skin (mouse bioassays).
As summarized by the API39:
“A number of crude oil samples, representing a range of compositions,
have been investigated for their potential to cause skin cancer in mouse
skin‐painting studies of 104‐110 week duration. All four crude oils
including some distillation fractions of API Crude C and D (See below),
produced skin tumors in 33‐100% of mice with latency periods of 40‐76
weeks, and were considered dermal carcinogens. Tumor incidence and
latency depended on crude oil source and dose (Table 18). Numerous
studies have shown that the mutagenic and carcinogenic potential of
complex petroleum‐related substances, all of which are derived from
crude oil, correlates with the presence of 3‐7 ring PAC. Further studies
have shown these PAC can be absorbed through the skin and enter
the general circulation.” (references deleted, emphasis added)
This assessment of the potential carcinogenicity of crude oil is supported by the
International Petroleum Industry Environmental Conservation Association (IPIECA):40
“For petroleum substances containing PAHs, the skin carcinogenic
potential is related to the level of specific 3‐7 fused‐ring PAHs. While
38 ibid. p. 59.
39 API 2011. p. 58.
40 IPIECA, June 17, 2010. Version 1. Guidance on the application of Gloabally Harmonized System (GHS)
critera to petroleum substances, at p. 10.

concentrations of specific PAHs can be determined, and certain PAHs are
classified as carcinogenic (e.g., by IARC), the skin carcinogenic potential of
petroleum substances should normally be assessed based on the whole
substance, taking into account the total PAH content. This is because
individual PAHs may occur at toxicologically insignificant
concentrations, but the total PAH‐content may be toxicologically
important.” [emphasis added]
For most people exposed to crude oil in developed countries, dermal contact and inhalation
of volatile components are considered the primary routes of exposure. However, in the
Concession Area, ingestion exposure – via drinking water, soils, and sediments – is also an
important consideration. Oral exposure was relegated to Appendix 5 in the API
submission to the US EPA because it was deemed an “unrealistic” route of exposure.
However, the API summary and the underlying data41 show that dermal and oral exposure
result in the same health effects, strongly suggesting that ingestion of crude oil also results
in cancer, including in particular, cancers in the gastrointestinal system. Moreover,
because the carcinogenic 3‐7 ring PACs are absorbed into the body, they may cause cancer
wherever they become located in the body.
2.6.2 Risk Of Cancer In The Concession Area Using HHRA Methodology
Like the risk assessment for non‐cancer hazards described in sections 2.4 and 2.5, cancer
risk from crude oil is most appropriately evaluated using a whole mixture approach with
carcinogenicity data based on tests using crude oil and exposure measured by the TEM
method. API and other industry groups have reported the results of cancer bioassays of
crude oil, but, unlike for the non‐cancer benchmark dose, have not quantified a cancer
potency factor.
In my December 2013 HHRA, the cancer risk calculation incorporated the published cancer
slope factors for six PAHs which comprise a very small portion of 3‐7 ring PACs, plus 1‐
methylnaphthalene, a 2 ring compound. However, many more 3‐7 ring PACs are known to
be carcinogenic based on toxicity testing, as discussed in section 2.6.1. Some of the
alkylated PAHs, such as 5‐methyl chrysene, are 100 times more carcinogenic than their
parent compound, in this case chrysene,42 yet only chrysene is currently included in US
EPA’s risk assessment methodology. Both are included in methodology recently proposed
by the State of California.43
Carcinogens that are not part of the 3‐7 ring PAC fraction have also been left out of the
cancer risk estimate. For example, carcinogens with fewer than 3 rings, such as
41 API 2011 and API 2003 High Production Volume Chemical Challenge Program. Test plan crude oil category.
Submitted to US EPA by API petroleum HPV testing group. November 21, 2003.
42 CA EPA (OHHEA) 2009. Appendix B (updated 2011) p B‐91.
43 CA EPA (OHHEA) 2014 op cit.

naphthalene and cumene (isopropylbenzene) have been detected in many Concession Area
samples, but are not included in the cancer risk calculation because US EPA has not
published a cancer toxicity factor. Cumene was first listed as a carcinogen this year (2014)
and more carcinogens may be identified as toxicity testing continues.44 Obviously, the US
EPA methodology based on only a few parent PAH (a subset of PAC) compounds
substantially underestimates carcinogenic risk of crude oil.
The carcinogenic 3‐7 ring PAC fraction is obtained using an analytical methodology that
was not used in any of the field samples in the Concession Area. However, the LBG dataset
provides the mass of alkyl substituted and parent PAHs for specified 3‐5 ring PAHs and a
few sulfur containing PACs (dibenzothiophenes). These are a portion of the 3‐7 ring PAC
fraction. Thus, while still an underestimate, the sum of the total amount of identified 3‐5
ring PAHs plus sulfur containing dibenzothiophenes, which ranges from 0.2‐5%, provides a
minimum measure of how small a fraction of potential carcinogenicity is evaluated by
currently available cancer slope factors.
Despite the substantial underestimate of cancer risk, my December 2013 HHRA resulted in
significant cancer risks for several well site/exposure pathway combinations. At LA02, use
of the nearby stream as a domestic water supply (a known former use) resulted in an
excess lifetime cancer risk of 1x10‐3 (one in a thousand). This estimate evaluates 0.5% and
4% of the 3‐7 ring PAC fraction for sediment and surface water, respectively. While this is
a former use, samples collected in 2014 from inside the house shows ongoing
contamination.45
2.7 Response To Additional Critiques From Claimants’ Experts
2.7.1 Barium Toxicity Is Evaluated Appropriately
Dr. McHugh suggests that I used an inappropriate measure for the toxicity of barium.46
According to him, I should have used toxicity based on barium sulfate because the elevated
barium concentrations are from Texpet’s use of barite‐containing drilling muds. His
argument assumes that: 1) barium sulfate is less toxic than other barium salts because it is
insoluble and therefore not well absorbed, and 2) barium sulfate is not converted to more
soluble barium salts while in the environment. Neither assumption is true.
According to the US EPA toxicological profile for barium,47 some studies show that barium
originating from both soluble and relatively insoluble barium salts is absorbed from the
44 US National Toxicology Program October 2014. Report on Carcinogens, 13th edition, Monograph on
Cumene, (monograph dated September 25, 2013).
45 The interior samples were wipe samples. They were collected using individually packaged alcohol wipes
rubbed against the surface. One wipe was used for the children’s toy. For the floor samples, each sample was
composed of 5 individual wipes. Each wipe was rubbed inside a 200 cm2 template.
46 Expert opinion of Thomas E. McHugh, May 2014. pp. 3 and 4.
47 US EPA 2005. Toxicological review of barium and compounds. EPA/635/R‐05/001.

gastrointestinal tract to a similar extent, likely due to the acidic environment of the
stomach. In addition, Chevron has not provided any data showing that barium sulfate is the
form found in the environmental samples. In fact, LBG has conducted an analysis of barium
concentrations in water and has concluded that, in certain samples, the barium is no longer
part of barium sulfate; it has been converted into a soluble salt.48
In my opinion, the US EPA reference dose is the most appropriate measure of toxicity of
barium in the waters, soils, and sediments in the Concession Area. I also note, however,
that barium, even using the US EPA reference dose, does not meaningfully contribute to the
non‐cancer hazards in the Concession Area. The vast majority of the estimated hazard is
from the crude oil, measured as TPH.
2.7.2 Surface Water Samples Should Not Be Filtered
Drinking water exposure should be based on unfiltered water samples (i.e., including
sediment to the extent it is suspended in the water) because that is what residents
consume and bathe in.49 Dr. McHugh’s statement that "the users would minimize the
amount of sediment in their drinking water to the extent possible" is yet another culturally
inappropriate and unfounded assertion. HHRAs assess exposure as a site would be used if
it were not contaminated. In the former Concession Area, water generally is consumed as
collected, sometimes in plastic bottles from streams near a farmer’s field (c.f., the farmer at
AG06), sometimes from buckets at wells or from bridges (c.f., LA16, SSF25), sometimes in
collection boxes (SSF13). In 2013, the LBG sampling team collected water samples in a
manner similar to that used by the residents. In the 2014 sampling program, LBG collected
surface water samples by peristaltic pump which had the consequence of minimizing the
inclusion of sediments. Data from samples collected in this manner may lead to an
underestimate of risk from water consumption.
2.7.3 Exposure Is Evaluated At Appropriate Locations
My December 2013 HHRA (as well as the HHRA included in this report) evaluated locations
where there was both visible and analytically measured contamination. Real, live people
live in these areas, although the sites were evaluated using risk assessment methodology
and exposure parameters appropriate for an RME receptor. Dr. McHugh, like the rest of
Claimants’ consultants, is trying to average the petroleum contamination over both clean
and dirty areas, thus diluting the exposure and subsequent risk that is experienced by
individuals living near contaminated well sites.
48 LBG Expert report November 2014 Section 3.4.3.1.
49 US EPA 1989, p. 6‐34.

The population in these rural areas is increasing,50 which means that even more people will
live near contaminated well sites and abandoned pits in the future. Risk assessment
methodology requires evaluating risk at future potential drinking water sources and other
exposure media. Both current and future exposure locations were sampled and evaluated,
and they are appropriate.
2.7.4 Exposure To Sediments And To Surface Water Is Evaluated Appropriately
Claimants contend that I evaluated the dermal uptake of contaminants in sediment
inappropriately. According to Dr. McHugh: “TPH measured in the surface water samples
was not dissolved, but rather was associated with sediment present in the water samples,
assuming uptake from both sediment and surface water double‐counts the exposure
resulting in an over estimation of risk from dermal uptake.”51
Dr. McHugh’s premise that the TPH measured in water is associated with sediment is not
substantiated. LBG has shown that oil (measured as TPH) in water samples can be in the
form of an emulsion, i.e., a mixture of water and oil, like shaken up salad dressing. In other
cases, it is a sheen, a separate phase in the water, or as oil droplets as shown in
photographs in the LBG opinion.52 Thus, the TPH measured in water is not necessarily
sediment associated. And even if the TPH were sediment‐associated, exposure to sediment
occurs via two different and independent exposure pathways (dermal exposure to water
and dermal exposure to sediment). US EPA methodology calls for evaluating these
exposure pathways separately and combining the results to calculate the cumulative risks
of exposure from all pathways.53
2.7.5 Dr. McHugh’s Citation Of His Personal Experience Is Culturally Inappropriate And An
Unreliable Basis To Develop Exposure Parameters In The Concession Area
Claimants and their consultants claim that my use of data collected using valid social
science methodology is “anecdotal” and thus unreliable. Yet Dr. McHugh offers opinions
based on his personal experience in a different climate, lifestyle, and culture. For example,
Dr. McHugh’s statement – “In my experience, parents try to minimize the time required to
bathe their infants” – does not provide a basis for assessing bathing habits in the
Concession Area. As I determined from my interviews with people living near the
contaminated well sites, bathing is for both cleaning and relief from the heat.
50 Observations of new housing construction, conversion of forested land to farm use, and rapid growth of
smaller towns (such as Shushufindi) reported by LBG, and INEC data for Concession Area cantons show that
both urban and rural populations are growing.
51 Expert opinion of Thomas E. McHugh, May 2014. p. 5.
52 LBG Expert Report November 2014. Section 3.4.1.
53 US EPA 1989, pp. 8‐15 ff.

Dr. McHugh suggests that I had not addressed his previous criticism regarding my use of
“anecdotal data”54 principally the Beristain et al. study with the English title “Words from
the Rainforest.”55 On the contrary, I did address his criticism in my December 2013
opinion.
In any event, the information in the Beristain report is consistent with the interview
reports prepared by Claimants’ consultants of the residents surrounding wells during their
Pre‐inspection Investigations, interviews with some of the same residents whom I spoke
with, observations of health effects of oil spills outside of the Concession Area (and outside
of Ecuador)56, and information on indigenous culture documented by anthropology and
other studies.57
3.0 Supplemental Opinion: Petroleum Contamination Has Reduced Local Food
Resources, Including Farm Animals, Crops, And Fish. The Reduced Availability
Of Home‐Produced Food Has Had An Adverse Impact On The Health Of The
Local Population That Relies On These Resources.
Farm animals intended for food use, including cows, chickens, ducks, and pigs come into
contact with soil, sediment, and surface water. Terrestrial wildlife that are hunted for
game as well as domestic animals such as horses and pets also come into contact with soil,
sediment, and surface water. Both wild fish and those raised in farm ponds come into
contact with sediment and surface water. Crude oil‐related contamination has been
detected above concentrations known to affect farm animals and fish at many of the well
sites.
3.1 Loss Of Livestock
The API developed guidance for cleaning up crude oil to protect livestock on contaminated
lands, specifically including land contaminated by closed oil pits that were dug as part of
the well installation.58 The API guidance assumes that there are no open pits or other free
oil accumulations on the ground, consistent with industry and regulatory guidance dating
back to at least the 1990s.
54 Expert opinion of Thomas E. McHugh, May 2014. p. 6. (in section 3).
55 Beristain, CM, DP Rovira, and I Fernadez. 2009. Words from the Rainforest. A psychosocial study of the
impact of Texaco’s petroleum operations on the communities of Ecuador’s Amazon. English translation of Las
Palabras de la Selva.
56 Laffon Expert Report 2014; Strauss Rejoinder Report December 2013; Strauss expert opinion February
2013.
57 c.f. Martínez et al. 2007 Impacts of Petroleum Activities for the Achuar People. of the Peruvian Amazon:
Summary of Existing Evidence and Research Gaps. Env. Res. Lett. 2:1‐10. Sirén, A.; J. Machoa 2008. Fish,
wildlife and human nutrition in tropical forests: A fat gap? Interciencia 33(3) pp. 186‐193.
58 API 2004. Risk Based Screening Levels for the Protection of Livestock Exposed to Petroleum
Hydrocarbons. Publication no. 4733.

Guidance was needed because:
“Consumption of petroleum hydrocarbons by livestock has been found to
lead to a range of health problems, including neurotoxicity, fetal toxicity,
damage to the gastrointestinal tract, respiratory system, kidney, and liver.
Petroleum ingestion has also been linked to anorexia, lethargy, and fatal
poisoning in cattle.”59 (references deleted).
API developed risk based soil and water screening values for livestock such as cows and
horses that are pastured, but not chickens and ducks, which it assumed are raised in
enclosed areas. However, in the Concession Area, chicken and ducks generally roam freely,
and thus are also subject to injury by oil.
Because it assumed there are no open pits, API’s livestock guidance is based on the
conceptual model depicted below in which a closed pit releases petroleum contamination
to soil and to surface water (either by overland flow or through groundwater). In this
model, livestock are exposed when consuming soil along with plant materials during
grazing, and by ingestion of contaminated drinking water.
Source (API, 2006)60
59 Ibid. p. 2‐1.
60 American Petroleum Institute (API) 2006. Livestock Exposure Brochure. API Creative Services | 2006‐059 |
06.06 | 300.

Chevron employees Sara McMillen and Renae Magaw were members of the workgroup and
review committee that developed the API livestock guidance. GSI has used livestock risk
based screening levels in the past,61 and prepared an issue paper on livestock exposure in
the Oriente, including development of risk‐based screening levels for pigs, ducks, and
chickens.62 Unfortunately, documentation of how these levels were derived was not
provided in the paper.
The chart below highlights the six well sites that violate the industry standard of no surface
accumulations of oil in agricultural areas. It also compares risk based screening levels
protective of farm animals such as cows, horses, goats, and sheep with TPH concentrations
found in certain surface soils near the well sites investigated by LBG in 2014.63 Surface and
shallow sediment data were compared with API’s risk based screening levels at all well
sites from which data were collected. The sites where at least one soil or sediment sample
exceeded the API screening levels are marked with a red oval (soil) or triangle (sediment).
The chart also summarizes reports of harm to crops or animals based on interviews in the
clickable database or by interviews conducted with landowners/tenants during my site
visit in June 2014.
61 GSI 0520535.
62 GSI0769161.
63 No surface soil samples were collected in the 2013 site investigation.

Eleven of the 13 well sites examined had observable surface accumulations of petroleum,
or at least one exceedance of a risk based livestock screening level or crop screening level.
LBG conducted only limited site investigations at the various well sites. No surface soil
samples were collected in the crop area at LA16 nor in the wetlands area at SSF43 where
animals reportedly contacted contamination and died. Thus, absence of an exceedance
should not be interpreted as absence of contamination.
As seen in the final column, the petroleum contamination causes observable harms to farm
animals, often resulting in the loss of the animal and the food or cash income it would
provide.
3.2 Contamination Of Fish Pond At SSF‐13
The farm at SSF13 has a fish pond similar to many in the region, where fish such as tilapia
are raised for personal consumption and possibly also for sale. However, no fish were
observed in this pond during the LBG field work in June 2014. A sediment sample collected
from the pond had a TPHTEM concentration of 320 mg/kg. The surface water had TPH8015
of 153 ug/L; naphthenic acids, which could only have come from crude oil, were present at
3.7 ug/L.64 In other words, residues of crude oil have reached and contaminated the surface
water and sediment of this fish pond.
3.3 Implications Of Livestock, Fish, Wild Game And Crop Loss
The loss of livestock and crops, chickens, ducks, eggs, and tilapia ponds, represents the loss
of both food for residents and cash income. The loss of fish in streams and wild game65 also
represents a loss of food for the subsistence farmers and indigenous people.66 The loss of
food has important effects on nutrition, including loss of both calories and a balanced diet
including fat and protein.67 These losses are particularly important in the Concession Area
because the children are already nutritionally deficient as evidenced by an approximately
50% rate of anemia in children under 5.68 Most, but not all, of the anemia responds to
treatment with supplemental vitamins and iron, which means that the anemia is due to
undernourishment. This local estimate of nutrition‐related anemia is consistent with the
World Health Organization’s statistics on chronic malnutrition in rural areas of Ecuador.69
64 LBG Expert Report 2014. Section 3.4.3.2.
65 Beristain et al. 2009 op cit; José Guamán witness statement (also interview July 2013).
66 Martínez et al. 2007 op. cit.
67 Sirén and Machoa 2008 op cit.
68 Estimate based on interview with Dr. Angel Jara Pinto, Sub Centro de Salud La Victoria on 6/13/14.
69 The World Health Organization (WHO) 2013 reports that chronic malnutrition in rural areas of Ecuador
decreased from 42.8% in 1999 to 35.5% in 2006, although the rate is twice that among indigenous
populations.

The health impacts of undernourishment and malnutrition are well known. The World
Bank70, in its summary of Ecuador, provides a general, lay summary of the health impact of
undernourishment:
 Undernourished children have an increased risk of falling sick and greater severity
of disease.
 Undernourished children who fall sick are much more likely to die from illness than
well‐nourished children.
In the language of risk assessment, the loss of food animals and crops makes the residents
of the Concession Area a susceptible population and thus more sensitive to the toxic effects
of the oil pollution.
4.0 Supplemental Opinion: Dr. Moolgavkar Used Highly Flawed Data As The
Basis Of His Cancer Study, Making His Results And Conclusions Unreliable And
Uninformative
Dr. Moolgavkar cited an opinion piece by J. P. A. Ioannidis titled “Why Most Published
Research Findings are False”71 in his May 2014 expert opinion. Ironically, his recently
published paper titled “Cancer mortality and quantitative oil production in the Amazon
region of Ecuador, 1990‐2010”72 most certainly falls into the category of false research
findings.
4.1 Cancer Mortality Data From The Oriente Are Unreliable
Dr. Moolgavkar’s analysis has a fundamental flaw: the mortality data on which he bases his
analysis, death certificate data from the Amazon region, are unreliable with respect to
cancer deaths. Obviously, the use of unreliable data yields results that are non‐informative
at best, and it can lead to false and misleading conclusions.
Dr. Moolgavkar and colleagues obtained all of their underlying cancer mortality data from
the Instituto Nacional de Estadistica y Censos (INEC), which in turn derives its data from
death certificate data submitted by health care workers throughout Ecuador. Interviews
with several health care providers in the Concession Area, including physicians who write
death certificates, revealed several reasons why death certificate data from the Concession
Area are unreliable and may substantially underreport the existence of cancer.
70 World Bank (undated). Ecuador Nutrition at a Glance. (downloaded from the World Bank website in
October 2014). The World Bank goes on to provide its summary of the economic impact of
undernourishment, but that is beyond the scope of my opinion.
71 Ioannidis, John P.A. 2005. Why Most Published Research Findings are False. PLoS Medicine, 2(8) e124.
72 Moolgavkar, SH, Change, ET, Watson, H, Lau, EC. 2014. Cancer Causes Control 25:59‐72.

The director of Hospital Provincial Marco Vinicio Iza Lago Agrio told me that death
certificates are notoriously inaccurate in terms of actual cause of death. He noted that they
often cite the immediate cause of death (e.g., cardiac arrest or multi‐organ failure) rather
than the underlying cause of death (e.g., cancer, heart disease, diabetes). Similarly, a
doctor at Shushufindi Hospital told me that everyone gets a death certificate and confirmed
that cancer would rarely if ever be listed as a cause of death on a death certificate.
Further, an unknown but potentially large percentage of cancers in the Concession Area are
not diagnosed formally,73 which can be done only at certain hospitals run by the Sociedad
de Lucha Contra el Cáncer (SOLCA hospitals) that specialize in cancer.74 Residents in the
Concession Area are usually referred to the SOLCA hospital in Quito. Many health care
providers in the Concession Area pointed out that poor people rarely seek formal diagnosis
or treatment because of the many barriers they face in getting to Quito. The residents living
nearest to the well sites, those most exposed to oil, are among the poorest of the
Concession Area (based on housing type, access to clean water, electricity, sanitary waste
disposal, and other measures). They are most at risk of cancer from oil exposures and yet
least likely to be counted in cancer incidence and cancer mortality studies.
One doctor estimated that 90% of the children referred to Quito for treatment don’t go.
Significantly, his estimate is based on only those residents who visit Shushufindi Hospital;
there may be a large number of sick people who do not even make the initial visit to the
local hospital. The health care workers interviewed at a primary care clinic, 18th de
Noviembre Centro de Salud, which refers patients to Shushufindi Hospital, reported
barriers to access, such as lack of transportation, to even this local hospital. Another doctor
at the Provincial Hospital in Lago Agrio also reported that not all patients go to Quito for
diagnosis and treatment, and his patients include those who have the means to get to the
main provincial hospital.
The inadequacy of death certificate data from the Oriente is well‐known and taken into
account in economic development plans for provinces. For example, the 2011
Development Plan for Orellana, referring to the two national registries for the principal
causes of death, points out that “[i]t is important to take into account that the information
from both sources is not always complete given that, in many cases, deaths take place in
remote places in the region without obtaining medical assistance or evaluation.”75 It is
unknowable how many of these deaths may have been due to cancer.
73 They are strongly suspected to have cancer based on clinical indications, which is why they are referred to
Quito.
74 The exception to this may be cervical cancer that can be diagnosed at the hospital in Lago Agrio. However,
this capability only became available 4 years ago (2010); at the very end of the time period studied by
Moolgavkar et al.
75 Gobierno Autónomo Provincial de Orellana 2011. Plan de Desarrollo de la Provincia de Orellana.
Caracterización Provincial. P. 177. The original Spanish is: “es importante tener en cuenta que la información
de ambas fuentes no siempre es completa ya que, en muchos casos, las muertes suceden en lugares apartados
de la región sin que se logre contar con asistencia o evaluación médica.”

Because the mortality data underlying Moolgavkar’s cancer study are inaccurate, the only
possible conclusion is that the study is non‐informative regarding cancer deaths in oil
producing areas; any conclusions drawn from the study are unsubstantiated.
4.2 Dr. Moolgavkar Uses An Inappropriate Measure Of Oil Exposure
Dr. Moolgavkar claims that his new study improves upon the exposure component (and
other components) of the study published in 2009 by Kelsh and co‐workers.76 By doing so,
he also implicitly claims that it is better than the exposure metric used by Hurtig and San
Sebastian in their publication.77 I disagree that Moolgavkar’s measure of exposure is better
than prior studies, and I continue to hold the opinion that the exposure metric used by
Hurtig and San Sebastian is more appropriate for two important reasons:
 Hurtig and San Sebastian focused their study on the Concession Area where Texpet
operated. In contrast, Moolgavkar and Kelsh included all oil‐producing areas
(Cascales, Cuyabeno) where other oil companies were the operators. Only Texpet’s
practices are relevant to the question of health effects caused by Texpet.
 Hurtig and San Sebastian required that exposure take place over a long period of
time (20 years), consistent with the common understanding that cancer develops
(in adults) following prolonged exposure. In contrast, Moolgavkar quantified oil
exposure by “well‐year”, the cumulative number of oil wells and total years of their
existence, modified by oil production volume as if it were equally distributed for
each well. Moolgavker does not require an extended period of exposure. In the
Moolgavkar (and Kelsh) exposure system, a newly installed high producing well can
count as much as an older, lower producing well, although the older well could
easily pose more risk. Moreover, exposure from abandoned wells, several of which
were evaluated in my HHRA in the previous section, are not included in the
Moolgavkar/Kelsh exposure system. Given that exposure in the Oriente is largely
through unremediated pits and spills, neither of which go away when a well is
abandoned, it is unreasonable to exclude them.
An additional problem with Dr. Moolgavkar’s methodology is that he sorted oil‐exposed
and unexposed cantons based on oil activity as of 1990. However, some of his unexposed
cantons have had substantial oil development post‐1990, as indicated in his Table 1. This
poses a problem because he evaluated this exposed/non‐exposed grouping using mortality
data from 1990‐2010. Thus, some of the populations he designates as unexposed have
actually been exposed during the period he is evaluating. He also ignores completely the
time period between 1970‐1990.
76 I opined on Kelsh’s work in my first Expert Opinion dated 2‐18‐13 at pp. 39‐40.
77 Hurtig AK, San Sebastian M. 2002. Geographical differences in cancer incidence in the Amazon basin of
Ecuador in relation to residence near oil fields. Int J Epidemiol, 31:1021‐7.

The many inadequacies related to epidemiological aspects of Dr. Moolgavkar’s
methodologies were addressed in Dr. Grandjean’s expert opinion of December 2013.

Technical Appendix 1: Details Of The Risk Calculations
I evaluated the data collected in LBG’s June/July 2014 field sampling program to evaluate
the risk of potential adverse health effects to current and future residents of the Concession
Area who might be exposed to the oil contamination. I used the same exposure assessment
methodology and parameters described in my December 2013 Rejoinder report for
exposure to surface water, groundwater, and sediment, with the exception of the modified
bathing times described in Section 2.3.3. Additional explanation for the exposure
parameters appears in section 2 of this report. I added exposure scenarios to surface soil
(child residential and adult farmer exposures) because surface and shallow soil data were
collected in the sampling 2014 program. In addition, as described in section 2.4.1 of my
report, I evaluated non‐cancer hazard using the preferred whole mixture approach in
addition to the commonly used fraction approach.
The surface soil exposure scenario is very similar to the sediment exposure scenario: it
includes soil ingestion and dermal contact, and requires exposure parameters for the
evaluation. For a child, surface soil non‐cancer hazard is based on daily exposure for
children who ingest 200 mg of soil, and who get dirt on their heads, hands, feet, forearms,
and lower legs. The average adherence factor (AF) for the dirt on their bodies is 0.2
mg/cm2. These child exposure parameters are the ‘default’ values used in a residential soil
scenario in a US EPA risk assessment.78
For adult farmers, the exposure scenario is based on daily contact with soil in an
agricultural setting, but without machines and the dust generated by them. The scenario
incorporates a soil ingestion rate of 200 mg/day based on the upper bound estimates of
soil ingestion from the State of California as described in section 2.3.2. It assumes the same
area covered with dirt as the sediment scenario, namely face, hands, forearms, lower legs,
and feet with a total exposed surface area (SA) of 6275 cm2. The adherence factor (AF) is
0.13 mg/cm2‐event. It is a weighted average of the measured AFs for these body parts in
the archeologist activity provided in the US EPA’s exposure factors handbook, as these are
the most similar to the Concession Area farmer.79 These exposure scenarios represent a
high end, but not extreme, exposure under conditions in the US. For residents living near
well sites in the Concession Area, it is more likely to be closer to a central tendency or
average exposure.
78 US EPA February 2014a, b op. cit.
79 US EPA 2011 (Exposure Factors Handbook) op. cit.

Technical Appendix 2: Development Of A Reference Dose For Crude Oil
An RfD is an estimate (with uncertainty spanning perhaps an order of magnitude) of a daily
oral exposure to the human population (including sensitive groups, such as asthmatics, or
life stages, such as children or the elderly) that is likely to be without an appreciable risk of
deleterious effects during a lifetime. An RfD is generally expressed in units of milligrams
per kilogram of bodyweight per day: mg/kg/day.
An RfD is determined by use of the following equation:
RfD = (experimental or benchmark dose)/uncertainty factors
The dose can be an experimentally determined no observed adverse effect level (NOAEL)
or lowest observed adverse effect level (LOAEL), or a benchmark dose that is calculated
from the experimental data and provides an estimate of the population that would be
affected (e.g., 10%) at a specified dose.
Uncertainty factors (UFs) take into account the variability and uncertainty that are
reflected in possible differences between test animals and humans (generally 10‐fold or
10x) and variability within the human population (generally another 10x); the UFs are
multiplied together: 10 x 10 = 100x. If a LOAEL is used, another uncertainty factor,
generally 10x, is also used. In the absence of key toxicity data (duration or key effects), an
extra uncertainty factor(s) may also be employed. Sometimes a partial UF is applied
instead of the default value of 10x, and this value can be less than or greater than the
default. Often the partial value is ½ log unit (the square root of 10) or 3.16 (rounded to 3‐
fold in risk assessment). Note, that when two UFs derived from ½ log units are multiplied
together (3 x 3) the result is a 10 (equal to the full UF from which the two partial factors
were derived).
I used a predicted benchmark dose, specifically a PDR10 from a repeated dose experiment,
as the basis for the reference dose calculation.80 Because different crude oils have different
toxicities, I used the lower end of the doses of the four crude oils with API gravities within
1o of Concession Area crude (the nearest PDR10s are: 93, 202, 130, 305), specifically a
PDR10 of 100 mg/kg‐d.
I applied a total uncertainty factor of 3000, which was a combination of the following
factors:
10x variability in the human population
10x differences between test animals and humans
10x use of a LOAEL rather than a NOAEL. A factor of 10 was used for two reasons: 1) the
benchmark dose is for an effect of 10% of the population and 2) the benchmark dose (or
the predicted benchmark dose, or PDR10) is the best estimate, not the lower bound
80 The PDR10 is similar to a BMD10 except it is a predicted dose based on API’s peer reviewed model.

estimate (BMDL10) that US EPA would typically use.
3x use of a repeated dose (90 day) rather than lifetime test.
RfD (dermal) = 100/3000 = 0.03 mg/kg‐day
I converted the RfD (dermal) to an RfD(oral) using a dermal absorption factor of 0.13, US
EPA’s default dermal absorption factor for all PAHs. In other words, only 13% of the PACs
applied dermally reach target organs inside the body compared to those taken in orally.
Accounting for this reduction in toxicity by the dermal route leads to an RfD(oral) of 0.004
mg/kg‐d.

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