      Case: 15-20641          Document: 00513928191              Page: 1         Date Filed: 03/27/2017




           IN THE UNITED STATES COURT OF APPEALS
                    FOR THE FIFTH CIRCUIT     United States Court of Appeals
                                                       Fifth Circuit

                                                                                                 FILED
                                                                                             March 27, 2017
                                            No. 15-20641
                                                                                              Lyle W. Cayce
                                                                                                   Clerk
MARK MCMANAWAY; DAVID RANCOURT; BRENT LASHER; JODY
AISTROP; WILLIAM BICKELL, et al,

                 Plaintiffs - Appellants

v.

KBR, INCORPORATED; KELLOGG BROWN & ROOT SERVICES,
INCORPORATED; KBR TECHNICAL SERVICES, INCORPORATED;
OVERSEAS ADMINISTRATION SERVICES, INCORPORATED; SERVICE
EMPLOYEES INTERNATIONAL, INCORPORATED; HALLIBURTON
COMPANY; HALLIBURTON ENERGY SERVICES, INCORPORATED,

                 Defendants - Appellees

------------------------------------------------------------------------------

ROCKY BIXBY; LAWRENCE ROBERTA; SCOTT ASHBY; CHARLES
ELLIS; MATTHEW HADLEY, et al,

                 Plaintiffs - Appellants

v.

KBR, INCORPORATED; KELLOGG BROWN & ROOT SERVICES,
INCORPORATED; KBR TECHNICAL SERVICES, INCORPORATED;
OVERSEAS ADMINISTRATION SERVICES, INCORPORATED; SERVICE
EMPLOYEES INTERNATIONAL, INCORPORATED,

                 Defendants - Appellees
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                                       No. 15-20641


                   Appeal from the United States District Court
                        for the Southern District of Texas


Before STEWART, Chief Judge, and SMITH and DENNIS, Circuit Judges.
JAMES L. DENNIS, Circuit Judge:
       This toxic tort case presents the question of whether Plaintiffs’ injuries
were caused by the alleged hexavalent chromium contamination at an
industrial water injection facility in Iraq. Plaintiffs are former American and
British soldiers who were assigned to protect employees at the facility.
Defendants, KBR, Incorporated and affiliated entities (KBR), 1 were tasked
with restoring the facility.        Plaintiffs claim that KBR did not responsibly
handle the contamination at the facility, leading Plaintiffs to suffer injuries
stemming from hexavalent chromium exposure. The district court granted
KBR’s motion for summary judgment dismissing Plaintiffs’ claims because of
their inability to prove that hexavalent chromium caused their injuries. On
appeal, Plaintiffs argue that they adduced sufficient evidence of causation to
survive summary judgment.               KBR argues that resolution of this case
necessarily calls into question non-justiciable military decisions and that
Plaintiffs’ claims are therefore barred by the political question doctrine. For
the reasons discussed below, we conclude that Plaintiffs’ claims are justiciable,
but we AFFIRM the district court’s summary judgment. 2



       1  Plaintiffs brought claims against KBR and its affiliates, and against Halliburton and
its affiliates. However, Plaintiffs’ claims against the Halliburton defendants were dismissed,
and Plaintiffs have not appealed those dismissals.

       2KBR also argues that this court should extend the Federal Tort Claims Act’s
combatant-activities exception to shield government contractors from liability when they are
involved in activities connected to the military’s strategic objectives. Unlike complete
preemption, which is a jurisdictional issue, the preemption raised by KBR is only an

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                                       No. 15-20641
                                              I
        In March 2003, the United States Army Corps of Engineers (USACE)
hired KBR to help restore Iraq’s oil infrastructure following the United States’
invasion as part of Project Restore Iraqi Oil (Project RIO). Pursuant to Task
Order 3 (part of KBR’s contract with USACE) KBR was to begin work on a
facility after USACE determined conditions were “benign.” Benign conditions
meant, among other things, that the site was “cleared of all enemy forces” and
“environmental       hazards” including           nuclear,   biological,   chemical, and
industrial hazards. USACE did not perform an environmental assessment of
Qarmat Ali, a water injection facility that KBR was tasked with restoring, and
it is unclear whether USACE declared conditions there benign. Nonetheless,
USACE (specifically, Task Force RIO) authorized KBR to start work at Qarmat
Ali on May 13, 2003, and KBR began work later that month. Plaintiffs are
current or former members of the Army National Guard or the British Royal
Airforce who provided military protection for KBR at Qarmat Ali.
        The company that operated Qarmat Ali prior to KBR’s arrival onsite
used sodium dichromate, an anti-corrosive agent and hexavalent chromium
compound, when injecting water into oil reservoirs for the purpose of forcing
oil to the surface. The use of sodium dichromate at Qarmat Ali, particularly
the improper storage of the substance, led to air and soil contamination.
Plaintiffs contend that they suffered injuries as a result of their exposure to
sodium dichromate, a known carcinogen and irritant, while working at Qarmat
Ali.



affirmative defense. See Spears Mktg., Inc. v. BancorpSouth Bank, 844 F.3d 464, 467 n.3
(5th Cir. 2016); Harris v. Kellogg Brown & Root Servs., Inc., 724 F.3d 458, 463 (3d Cir. 2013)
(“Absent complete preemption, whether a plaintiff’s claims are preempted relates to the
merits.”). Because we affirm the district court’s grant of summary judgment, we do not reach
KBR’s preemption argument.

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                                No. 15-20641
      In the district court, Plaintiffs adduced evidence that they were exposed
to sodium dichromate. For example, they submitted a Royal Airforce report
concluding that “operational activity would suggest” that soldiers working at
Qarmat Ali were exposed to sodium dichromate, although the extent of the
exposure could not “be satisfactorily quantified.” Plaintiffs also submitted a
2008 National Guard memorandum concluding that soldiers at Qarmat Ali
“had a high potential for direct exposure,” and an October 2003 report from the
Army Center for Health Promotion and Preventive Medicine, concluding that
before containment of the chemical, “chromium concentrations exceeded
(military) health risk screening values,” and exposure “[p]robably occurred to
some degree prior to containment.” Moreover, August 2003 urine and blood
sampling of twenty-seven KBR employees who worked at Qarmat Ali showed
that four of the tested employees had higher-than-normal levels of chromium
in their urine and twenty-three of the tested employees had higher-than-
normal levels of chromium in their blood.
      Plaintiffs contend that exposure to sodium dichromate was deleterious
to their health, both during and after their service at Qarmat Ali. Plaintiff
Jody Aistrop observed that “[e]verybody” in his company complained of
nosebleeds and rashes and that he experienced such symptoms, as well as
gastrointestinal distress. Plaintiff Russell Powell, a medic, observed that he
and other soldiers experienced “intense” gastrointestinal problems. Plaintiff
Russell Kimberling developed headaches, respiratory problems, diarrhea, skin
rashes, and a septal hole. In 2009, Lieutenant Colonel James Gentry died of
lung cancer. The Army deemed his death to be “In Line of Duty for Exposure
to Sodium Dichromate between June – September 2003.”




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                                       No. 15-20641
       In 2010, a group of plaintiffs filed suit in the Southern District of Texas, 3
alleging negligence, gross negligence, fraud, and intentional infliction of
emotional distress. Plaintiffs claimed that KBR was aware of the sodium
dichromate contamination at Qarmat Ali and failed to take appropriate steps
to reduce the risk of harm to the soldiers, to inform the U.S. or British military,
or to warn the soldiers who were exposed to the contamination. Plaintiffs
claimed that KBR’s tortious actions caused them to suffer, among other
ailments, nose bleeds, skin lesions, physical pain, emotional distress, and
death.
       In the district court, KBR filed a motion to dismiss on the grounds that
the case presented a non-justiciable political question and that Plaintiffs’
claims were preempted by federal common law. The court denied this motion. 4
KBR also moved for summary judgment claiming, inter alia, that Plaintiffs
could not establish that sodium dichromate caused their injuries. The court
granted KBR’s motion for summary judgment, dismissing Plaintiffs’ claims on
causation grounds and, separately, granted KBR’s motion for summary
judgment, dismissing individual plaintiff Lieutenant Colonel James Gentry’s




       3A related case brought by Oregon National Guardsmen who worked at Qarmat Ali
went to trial in the District of Oregon, resulting in a jury verdict against KBR. The verdict
was vacated on jurisdictional grounds. See Bixby v. KBR, Inc., 603 F. App’x 605 (9th Cir.
2015). The Oregon case was then transferred to the Southern District of Texas and
consolidated with the Texas case on September 25, 2015.

       4The district court certified its ruling for interlocutory appeal, and this court granted
KBR leave to appeal. After hearing oral argument, however, a panel of this court dismissed
the appeal as improvidently granted. McManaway v. KBR, Inc., No. 12-20763, 2013 WL
8359992 (5th Cir. Nov. 7, 2013). KBR sought rehearing en banc, which was denied. See
McManaway v. KBR, Inc., 554 F. App’x 347 (5th Cir. 2014).


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                                     No. 15-20641
claims on similar grounds. The court entered judgment in favor of KBR.
Plaintiffs timely appealed. 5
                                            II
       We review a district court’s summary judgment decision de novo. Davis
v. Fernandez, 798 F.3d 290, 292 (5th Cir. 2015).                Summary judgment is
appropriate if “there is no genuine dispute as to any material fact and the
movant is entitled to judgment as a matter of law.” FED. R. CIV. P. 56(a). A
genuine issue of material fact exists “if the evidence is such that a reasonable
jury could return a verdict for the nonmoving party.” Anderson v. Liberty
Lobby, Inc., 477 U.S. 242, 248 (1986). When reviewing a summary judgment
decision, we view all facts in the light most favorable to the non-moving party.
See Tolan v. Cotton, 134 S. Ct. 1861, 1863 (2014). It is not the role of the court
to make credibility determinations, or to weigh evidence when ruling on a
motion for summary judgment. See Anderson, 477 U.S. at 255. However, in
reviewing expert opinion evidence, “we look to the basis of the expert’s opinion,
and not the bare opinion alone.” Wackman v. Rubsamen, 602 F.3d 391, 400
(5th Cir. 2010) (quoting Guile v. United States, 422 F.3d 221, 227 (5th Cir.
2005)). “A claim cannot stand or fall on the mere ipse dixit of a credentialed
witness.” Guile, 422 F.3d at 227 (quoting Archer v. Warren, 118 S.W.3d 779,
782 (Tex. App. 2003)).
                                           III
       Before we discuss the merits of the Plaintiffs’ arguments on appeal, we
must address a possible jurisdictional bar to our review of this case: the
political question doctrine. See Spectrum Stores, Inc. v. Citgo Petroleum Corp.,




       5Plaintiffs appealed other rulings, the merits of which we do not reach because lack
of causation is dispositive of all of Plaintiffs’ tort claims.

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                                   No. 15-20641
632 F.3d 938, 943 (5th Cir. 2011); see also Schlesinger v. Reservists Comm. to
Stop the War, 418 U.S. 208, 215 (1974).
      “[T]he purpose of the political question doctrine is to bar claims that have
the potential to undermine the separation-of-powers design of our federal
government.” Lane v. Halliburton, 529 F.3d 548, 559 (5th Cir. 2008); see Nixon
v. United States, 506 U.S. 224, 253 (1993) (Souter, J., concurring in judgment)
(observing that the doctrine “deriv[es] in large part from prudential concerns
about the respect we owe the political departments”).             When a political
question “is inextricable from the case at bar,” Baker v. Carr, 369 U.S. 186, 217
(1962), “a court lacks the authority to decide the dispute before it,” Zivotofsky
v. Clinton, 566 U.S. 189, 195 (2012). The Supreme Court has explained that a
case involves a political question where, inter alia, “there is a ‘textually
demonstrable constitutional commitment of the issue to a coordinate political
department; or a lack of judicially discoverable and manageable standards for
resolving it.’” Id. (quoting Nixon, 506 U.S. at 228).
      “[W]ar and foreign policy decisions,” including “decisions whether and
under what circumstances to employ military force are constitutionally
reserved for [the political] branches.” Lane, 529 F.3d at 559 (citation omitted).
However, the political question doctrine does not prevent courts from
entertaining every claim involving alleged military wrongdoing. See Gilligan
v. Morgan, 413 U.S. 1, 11–12 (1973) (noting that the military’s conduct is not
always beyond judicial review); cf. Baker, 369 U.S. at 217 (“The doctrine of
which we treat is one of ‘political questions,’ not one of ‘political cases.’”). Thus,
before declaring a case involving military decision-making to be non-justiciable
under the political question doctrine, “a court must undertake ‘a
discriminating analysis of the particular question posed, in terms of the history
of its management by the political branches, of its susceptibility to judicial


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                                       No. 15-20641
handling in the light of its nature and posture in the specific case, and of the
possible consequences of judicial action.’” Lane, 529 F.3d at 559 (quoting
Baker, 369 U.S. at 211–12).
       In Lane v. Halliburton, this court addressed allegations of fraudulent
misrepresentation       and negligence         by military       contractors     KBR      and
Halliburton. Id. at 554. Plaintiffs, former KBR employees, claimed that KBR
misrepresented the risks that they would face as truck drivers in Iraq. Id. at
554–55. The panel found that, for the political question doctrine to bar the
plaintiffs’ claims, (1) the claims against KBR must “require reexamination of
a decision by the military” and (2) “the military decision at issue [must
be] insulated from judicial review.”              Id. at 560 (quoting McMahon v.
Presidential Airways, Inc., 502 F.3d 1331, 1359 (11th Cir. 2007)). The Lane
court found that, viewing the facts in the light most favorable to the plaintiffs,
the plaintiffs’ claims only required the court to analyze KBR’s actions, “which
[could] be examined by a federal court without violating the Constitution’s
separation of powers.” Id. The court ultimately concluded that the case needed
further factual development before it could be determined whether the political
question doctrine barred the plaintiffs’ claims. Id. at 554. 6
       Here, Plaintiffs’ claims are directed at private parties, and do not on
their face address decisions constitutionally committed to a coordinate branch.
Thus, under Lane, KBR must show that the claims will require reexamination



       6  Other circuits have similarly found that whether suits against military contractors
are barred by the political question doctrine is a fact-intensive question. See Metzgar v. KBR,
Inc. (In re KBR, Inc.), 744 F.3d 326, 334 (4th Cir. 2014) (“[A]lthough cases involving military
decision making often fall in the political question box, we cannot categorize such a case as
nonjusticiable without delving into the circumstances at issue.”); Harris, 724 F.3d at 466
(“[T]o avoid infringing on other branches’ prerogatives in war-time defense-contractor cases,
courts must apply a particularly discriminating inquiry into the facts and legal theories
making up the plaintiff’s claims as well as the defendant’s defenses.”).

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                                 No. 15-20641
of a military decision that is insulated from judicial review. See id. at 560.
KBR argues that it would defend against Plaintiffs’ claims by arguing that the
military knew of potential sodium dichromate contamination at Qarmat Ali yet
still chose to deploy soldiers there. According to KBR, evaluating this defense
would require review of “military wartime decisions” that are demonstrably
committed to the Executive Branch.          KBR also argues that there are no
judicially discoverable and manageable standards for resolving the question of
who caused Plaintiffs’ injuries, as “[a]ny trial of this case would necessarily
require a jury to scrutinize these military decisions that are inextricably
intertwined with KBR’s causation defense.” Further, KBR contends that we
should find that the district court erred in denying its motion to designate the
United States “military” as a responsible third party under section 33.004 of
the Texas Civil Practice and Remedies Code, and claims that designating the
United States a responsible third party means that “KBR was entitled to have
the jury allocate fault to the military” and that “this suit is not justiciable.”
However, as discussed in the following section, Plaintiffs have failed to carry
their burden at the summary judgment stage.          We will not undertake a
searching review of a hypothetical case when, as evidenced by the parties’
briefing of the merits issues before us, this appeal “primarily raise[s] legal
questions that may be resolved by the application of traditional tort
standards,” Lane, 529 F.3d at 563, which are plainly discoverable and
manageable by the judiciary.
                                       IV
      To prove their tort claims against KBR—fraud, negligence, gross
negligence, and intentional infliction of emotional distress—Plaintiffs must
establish that KBR’s conduct caused their injuries. See, e.g., Wheaton Van




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                                        No. 15-20641
Lines, Inc. v. Mason, 925 S.W.2d 722, 728 (Tex. App. 1996). 7 The district court
found that Plaintiffs’ evidence was insufficient to prove causation because their
expert’s methodology did not adequately explain the connection between their
exposure levels and their injuries and Plaintiffs failed to provide sufficient
epidemiological support to show that sodium dichromate exposure caused their
alleged injuries. 8 On appeal, Plaintiffs argue that the admission of expert
testimony supporting causation bars summary judgment, that their expert’s
“differential diagnosis” is sufficient to establish causation, and that lay
testimony is sufficient to establish causation for their acute injuries. 9
       To survive summary judgment, Plaintiffs must establish a genuine issue
of material fact as to whether exposure to sodium dichromate caused their
injuries “based on a reasonable medical probability and scientifically reliable
evidence.”     Black v. Food Lion, Inc., 171 F.3d 308, 310 (5th Cir. 1999).



       7 The district court found, and the parties do not dispute, that Texas law applies to
Plaintiffs’ tort claims.

       8  The district court issued a separate order dismissing Plaintiffs’ “genetic
transformation” injuries on the ground that Plaintiffs were asymptomatic. Plaintiffs have
presented no arguments in this court regarding this order and therefore we find any such
argument forfeited. See Carl E. Woodward, L.L.C. v. Acceptance Indem. Ins. Co., 743 F.3d
91, 96 (5th Cir. 2014).

       9  Plaintiffs claim that the district court erred by dismissing their tort claims on
grounds that KBR did not raise: (1) the flaws of their expert’s use of “exposure categories”—
estimated based on self-reported time at Qarmat Ali—to determine whether an injury was
caused by sodium dichromate; and (2) the expert’s failure to consider the date Plaintiffs
arrived on site as part of this analysis. However, KBR essentially raised the causation issues
addressed by the district court by challenging Plaintiffs’ experts’ use of exposure categories
as a proxy for dose, and by urging that it was logically flawed to assume that arrival at
Qarmat Ali at any time would result in exposure to substantially the same dose of sodium
dichromate due to varying weather conditions. Causation is an essential element of
Plaintiffs’ claims, and KBR’s arguments put them “on notice that [they] had to come forward
with [their] evidence.” Lemoine v. Wolfe, 575 F. App’x 449, 456 (5th Cir. 2014) (quoting
Celotex Corp. v. Catrett, 477 U.S. 317, 326 (1986) (alterations in original)). Thus, the district
court did not raise dispositive issues sua sponte.

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Plaintiffs must show both that sodium dichromate is capable of causing their
alleged injuries (“general causation”) and that it did, in fact, cause their
injuries (“specific causation”).   See Merrell Dow Pharm., Inc. v. Havner, 953
S.W.2d 706, 714 (Tex. 1997). It is not enough that Plaintiffs have produced
some expert testimony supporting their position, as “the reliability of expert
testimony is . . . a prerequisite to its legal sufficiency.” Abraham v. Union Pac.
R.R. Co., 233 S.W.3d 13, 17 (Tex. App. 2007) (citing id.).
      Plaintiffs offered expert testimony from Dr. Arch Carson, a medical
doctor who specializes in treating individuals “who have been exposed to
industrial chemical substances,” and Dr. Herman Gibb, an epidemiologist who
has published several influential journal articles concerning the health effects
of chromium. Gibb opined to “a reasonable degree of scientific certainty” that
the Plaintiffs “have increased risks for a variety of health effects as a result of
their exposure to sodium dichromate[, including] lung cancer; dermal and
respiratory allergic response to chromium; other respiratory effects; and renal,
gastrointestinal, and reproductive effects.”      In forming his opinion, Gibb
examined litigation documents, including Plaintiffs’ medical records. Gibb
said that he did not have air quality measurements or other “quantitative
information” that would enable him to make a dose-response assessment—an
assessment describing the effects caused by differing levels of exposure. He
opined that, given the lack of data, it was “impossible” to estimate each
plaintiff’s exposure. However, he testified that “the reporting of symptoms and
the description of the exposure” indicated that Plaintiffs incurred similar
exposure to a cohort of industrial workers he had studied, and that Plaintiffs
“had enough exposure to . . . develop symptoms like irritation and so-forth.”
      Carson opined that, within reasonable medical probability, many of the
Plaintiffs’ injuries were caused by exposure to sodium dichromate at Qarmat


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Ali.      Carson detailed three categories of Plaintiffs’ injuries: genetic
transformation injuries, characterized by cell damage and an attendant
heightened risk of cancer; acute irritation injuries, such as skin irritation,
breathing difficulties, eye irritation, nosebleeds, sinus problems, headaches,
persistent coughing, and gastro-intestinal irritation; and remote exposure
injuries, such as ongoing skin, respiratory and gastrointestinal problems. In
arriving at his conclusions, Carson examined litigation documents, physically
examined the Plaintiffs, and studied Plaintiffs’ medical records.
         As part of his methodology, Carson assigned each plaintiff he examined
a control number reflecting that plaintiff’s self-reported time spent at Qarmat
Ali. Carson did not consider the specific dates a plaintiff was stationed at
Qarmat Ali, considering only the total time each plaintiff reported being at the
site. Carson used these control numbers to put each plaintiff into an “exposure
category.” Carson gauged whether Plaintiffs’ injuries were caused by sodium
dichromate based on the assigned exposure categories. He testified, “The
exposure category followed directly from the control number, and was only
utilized in terms of my determination whether or not the relationship between
chromium exposure and symptoms or illnesses was plausible.” He agreed his
methodology was to “look at people and compare the symptoms that they
claimed as compared to the exposure category [he] had put them [in] and reach
conclusions based on that.” Carson did not create any tables or summaries of
these exposure categories or their application.
         This exposure category analysis was Carson’s only quantitative analysis
of Plaintiffs’ dosage. He stated that, to his knowledge, there were “no credible”
exposure measurements. Carson testified that he did not know the dose of
sodium dichromate any particular individual plaintiff was exposed to.




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Nevertheless, he opined that the level of exposure was “many orders of
magnitude or much greater than historical industrial exposures” based on:
       the amount of contamination; the type of area it was; the fact that
       it was extremely dry most of the time, although it did rain
       occasionally; that it was very windy, that there were recurrence
       [sic] of windstorms periodically; and the preponderance of acute
       irritative symptoms that the Guardsmen out there and the KBR
       personnel experienced.

Carson opined that Plaintiffs’ dosage was higher than that received by the
subjects of Gibb’s study and quoted Gibb’s report stating that the
contamination at Qarmat Ali was similar to that of a “Superfund site[].” 10
However, he testified that he was not aware of any studies that have
conclusively shown that there are health effects in humans from exposure to a
hexavalent chromium compound, such as sodium dichromate, in an outdoor
setting like a Superfund site.
       The Texas Supreme Court held in Merrell Dow Pharmaceuticals, Inc. v.
Havner that, in the absence of direct evidence of causation, plaintiffs may rely
on epidemiological studies 11 to prove causation where such studies
demonstrate a statistically significant doubling of the risk of the injuries
alleged. 953 S.W.2d at 718; see Merck & Co. v. Garza, 347 S.W.3d 256, 265
(Tex. 2011). Moreover, “[t]o raise a fact issue on causation” a plaintiff “must
show that he or she is similar to those in the studies.” Havner, 953 S.W.2d at
720. Proof that one is similarly situated to subjects in epidemiological studies



       10 A Superfund site is an area that has been contaminated by toxic waste and
designated for remediation by the Environmental Protection Agency. See United States v.
Gen. Elec. Co., 670 F.3d 377, 381 n.3 (1st Cir. 2012).

       11 “Epidemiological studies examine existing populations to attempt to determine if
there is an association between a disease or condition and a factor suspected of causing that
disease or condition.” Havner, 953 S.W.2d at 715.

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must “include proof that the injured person was exposed to the same substance,
that the exposure or dose levels were comparable to or greater than those in
the studies, that the exposure occurred before the onset of injury, and that the
timing of the onset of injury was consistent with that experienced by those in
the study.” Id. To prove causation through epidemiological studies, a plaintiff
must provide more than one study that meets this criteria. See Garza, 347
S.W.3d at 266; Havner, 953 S.W.2d at 727. Moreover, “other plausible causes
of the injury or condition that could be negated [must be excluded] with
reasonable certainty.” Garza, 347 S.W.3d at 265–66 (quoting Havner, 953
S.W.2d at 720); see also Cotroneo v. Shaw Env’t & Infrastructure, Inc., 639 F.3d
186, 193 (5th Cir. 2011).
      Plaintiffs do not argue that their evidence complies with the Havner
standard, arguing instead that epidemiological studies are not the exclusive
means of establishing causation.      However, Plaintiffs do seek to rely on
epidemiological studies, citing to, inter alia, Gibb’s studies of chromate-
production workers who were exposed to hexavalent chromium at a factory.
And, where a plaintiff seeks to rely on epidemiological evidence, Texas law
requires that the studies show a statistically significant doubling of the risk of
developing their alleged injuries. See Garza, 347 S.W.3d at 265 (“Havner holds,
and we reiterate, that when parties attempt to prove general causation using
epidemiological evidence, a threshold requirement of reliability is that the
evidence demonstrate a statistically significant doubling of the risk.”); see also
Young v. Mem’l Hermann Hosp. Sys., 573 F.3d 233, 236 (5th Cir. 2009).
      The studies relied on by the Plaintiffs and their experts do not reflect a
statistically significant doubling of the risk of their injuries. One of these
studies did not quantify the risk of developing Plaintiffs’ chromium-related-
acute-irritation injuries at all and the other study did not find a doubling of


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                                  No. 15-20641
the risk. In addition to Gibb’s studies, Plaintiffs reference National Institute
for Occupational Safety and Health and Agency for Toxic Substances and
Disease Registry reports concluding that sodium dichromate causes headaches
and nose, throat, skin, respiratory tract and gastro-intestinal irritation.
Plaintiffs also claim that Carson relied on “numerous scientific articles
supporting his contention that sodium dichromate causes various ailments.”
Plaintiffs did not submit these studies into the record and do not claim that
any demonstrates a statistically significant doubling of the risk of any of their
injuries. While the reliability of expert testimony is to be viewed in light of the
totality of the evidence, “[t]he totality of the evidence cannot prove general
causation if it does not meet the standards for scientific reliability established
by Havner. A plaintiff cannot prove causation by presenting different types of
unreliable evidence.” Garza, 347 S.W.3d at 268.
      Because none of this epidemiological evidence meets the reliability
threshold of Havner and its progeny, it cannot be considered competent
summary judgment evidence establishing general causation. See id.; Daniels
v. Lyondell-Citgo Refining Co., 99 S.W.3d 722, 730 (Tex. App. 2003). Because
the evidence underlying Gibb’s and Carson’s opinions is unreliable as a matter
of Texas law, their testimony is also insufficient to prevent summary judgment.
See Havner, 953 S.W.2d at 714.
      Plaintiffs argue that, notwithstanding this deficiency, their claims
should still survive summary judgment.           First, Plaintiffs claim that “a
differential diagnosis [excluding other potential causes of injury] constitutes
an accepted means of proving causation when it is scientifically accepted that
a particular toxin is capable of giving rise to the underlying injury.” However,
a differential diagnosis is only relevant after general causation has been
reliably established “because a differential diagnosis presumes that chemical


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                                  No. 15-20641
X can cause condition Y generally, but does not itself so prove.”          Coastal
Tankships, U.S.A., Inc. v. Anderson (In re Estate of Anderson), 87 S.W.3d 591,
609 (Tex. App. 2002). Carson’s differential diagnosis does not relieve Plaintiffs
of their burden of adducing reliable evidence of general causation. See Johnson
v. Arkema, Inc., 685 F.3d 452, 469 (5th Cir. 2012) (upholding exclusion of
expert’s differential diagnosis where there was no “reliable or relevant
scientific evidence” to support the expert’s presumption of general causation);
Matt Dietz Co. v. Torres, 198 S.W.3d 798, 805 (Tex. App. 2006) (finding
differential diagnosis insufficient to establish causation where there was no
reliable evidence that “exposure to a specific substance at specific levels [could]
cause the injury in question”).
      Second, Plaintiffs argue that, regardless of the sufficiency of their expert
testimony, they have adduced sufficient evidence of causation for their acute
injuries on the basis of lay testimony. While Plaintiffs correctly argue that
they need not cite a particular case in the district court to rely on it on appeal,
Plaintiffs failed to argue in their opposition to summary judgment in the
district court that lay testimony was sufficient to support causation. They
similarly failed to rely on lay testimony in their motion for reconsideration of
the district court’s decision on causation. We will generally not countenance
arguments not raised before the district court. See, e.g., Keenan v. Tejeda, 290
F.3d 252, 262 (5th Cir. 2002) (“If a party fails to assert a legal reason why
summary judgment should not be granted, that ground is waived and cannot
be considered or raised on appeal.” (quoting Grenier v. Cyanamid Plastics, Inc.,
70 F.3d 667, 678 (1st Cir. 1995))). We therefore deem this argument forfeited.




                                        16
    Case: 15-20641       Document: 00513928191          Page: 17     Date Filed: 03/27/2017



                                       No. 15-20641
       For these reasons, we find that Plaintiffs have not adduced sufficient
evidence to avoid summary judgment. 12
                                             ***
       In light of the foregoing, we AFFIRM the district court’s grant of
summary judgment and dismissal of Plaintiffs’ claims.




       12  The district court separately addressed the claims of Lieutenant Colonel James
Gentry, a former member of the Indiana National Guard who died of lung cancer in 2009.
Like the other plaintiffs, Gentry brought claims of negligence, gross negligence, intentional
infliction of emotional distress, and fraud against KBR arising out of his exposure to sodium
dichromate at Qarmat Ali. As with the other plaintiffs, Gentry’s claims are not supported by
two Havner-compliant epidemiological studies which show a doubling of the risk of
developing lung cancer. Plaintiffs cite one study which showed a relative risk factor of 2.24.
Plaintiffs allude to “numerous other studies that demonstrate an elevated lung cancer
mortality associated with hexavalent chromium,” but they have not argued that any of these
shows a statistically significant doubling of the risk of developing lung cancer. As discussed
above, Carson’s differential diagnosis does not cure these problems, even if we assume his
methodology is reliable. See Johnson, 685 F.3d at 469. Thus, the district court correctly
granted summary judgment in favor of KBR with respect to Gentry’s individual claims.

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