J-S39014-17
NON-PRECEDENTIAL DECISION - SEE SUPERIOR COURT I.O.P. 65.37
RICHARD THOMAS WALSH, : IN THE SUPERIOR COURT OF EXECUTOR OF THE ESTATE OF : PENNSYLVANIA THOMAS J. WALSH, DECEASED : : Appellant : : : v. : : No. 1661 WDA 2016 : BASF CORPORATION; BAYER : CORPORATION D/B/A BAYER : CROPSCIENCE, L.P., AND BAYER : CROPSCIENCE HOLDING, INC., : AND/OR BAYER CROPSCIENCE, L.P. : AND BAYER CROPSCIENCE : HOLDING, INC., IN THEIR OWN : RIGHT; BIOSAFE SYSTEMS, L.L.C.; : CHEMTURA CORPORATION; CLEARY : CHEMICAL CORP.; DOW : AGROSCIENCES, L.L.C.; E.H. : GRIFFITH, INC.; E.I. DU PONT DE : NEMOURS AND CO., INC.; G.B. : BIOSCIENCES CORPORATION; : JOHN DEERE LANDSCAPING, INC., : SUCCESSOR TO LESCO, INC.; : MONSANTO COMPANY; NUFARM : AMERICAS, INC.; REGAL CHEMICAL : CO.; SCOTTS-SIERRA CROP : PROTECTION CO.; AND SYNGENTA : CROP PROTECTION, INC. :
Appeal from the Order Entered October 14, 2016 In the Court of Common Pleas of Allegheny County Civil Division at No(s): G.D. No. 10-018588
BEFORE: BENDER, P.J.E., BOWES, J., and STRASSBURGER*, J. FILED MAY 22, 2018
MEMORANDUM BY BOWES, J.:
____________________________________ * Retired Senior Judge assigned to the Superior Court. J-S39014-17
Richard Thomas Walsh, Executor of the Estate of Thomas J. Walsh,
Deceased, appeals from the October 14, 2016 order granting summary
judgment in favor of Appellees, and challenges the propriety of the trial court’s
order barring his experts from testifying pursuant to the standard enunciated
in Frye v. United States, 293 F. 1013 (D.C. Cir. 1923). Since we conclude
that the learned trial court erred in the manner in which it conducted the Frye
inquiry herein, we reverse the grant of summary judgment, vacate the order
precluding Mr. Walsh’s experts from testifying, and remand for further
proceedings.1
The record reveals the following. The Decedent, Thomas J. Walsh, was
employed for almost forty years as a groundskeeper and golf course
superintendent at several golf courses in the Pittsburgh area. During his
employment, he frequently and regularly applied insecticides and fungicides
(collectively “pesticides”) on the golf courses. He kept a diary of the chemicals
used on the courses and the dates of their applications. His friend and co-
worker, Blaise Santoriello, offered specific details about how the two men
applied the pesticides, what pesticides were used, in what concentrations, and
the protective gear worn. Most of the applications occurred from May through
September.
Early on, according to Mr. Santoriello, Mr. Walsh came into physical
contact with pesticides while holding the hose spraying pesticides. Gloves ____________________________________________
1 We grant Monsanto Company’s motion to withdraw the appearance of Daniel R. Blakey, Esquire, filed on June 15, 2017.
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were the only protective gear used. Later, the men wore masks and rubber
boots and overalls that they would re-wear without laundering. He recounted
an instance in the mid-1980s when Mr. Walsh experienced an adverse reaction
to a product. That prompted a change to disposable protective gear. Yet, Mr.
Santoriello explained that, even then, they would be exposed to the dust from
the products while opening the bags, mixing the chemicals, and holding the
hoses.
On October 5, 2008, Mr. Walsh presented to the emergency room
complaining of fever, chills, and a cough. Three days later, after a bone
marrow biopsy, he was diagnosed with Acute Myelogenous Leukemia (“AML”).
Subsequent cytogenetic testing at West Penn Hospital showed chromosomal
aberrations consistent with secondary leukemias, which are linked to
radiation, chemotherapy, or chemical exposure.
Mr. Walsh died on February 2, 2009. His treating oncologist, James
Rossetti, D.O., later opined that Mr. Walsh’s extensive chemical exposure,
together with “the high-risk karyotype and dyspoietic features associated with
[AML] raise a high degree of suspicion that such [occupational pesticide]
exposure played a significant role in the development of his disease.” Letter
Report of James M. Rossetti, D.O., 7/19/12, at 4.
Executor commenced this wrongful death and survival action against the
manufacturers of various pesticides that Decedent applied over the forty-year
period, asserting claims in strict products liability, negligence, and breach of
warranty. Summary judgment was granted in favor of the manufacturers and
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sellers of more than twenty-five of the allegedly defective pesticides on
December 11, 2012, based on a lack of expert testimony identifying these
pesticides as substantial contributing factors in Mr. Walsh’s death. Fifteen
products remained in the lawsuit when the rulings that are the subject of this
appeal were made.2
On August 5, 2013, the Bayer Defendants filed a motion to exclude
Executor’s experts, epidemiologist April Zambelli-Weiner, Ph.D., and physician
Nachman Brautbar, M.D., pursuant to Frye v. United States, 293 F. 1013
(D.C. Cir. 1923). The other remaining defendants either joined Bayer’s Frye
motion or filed their own. The substance of the Frye motions was that this
case involved novel science, and the methodologies used by these experts
were not generally accepted or conventionally applied in the relevant scientific
communities.
The trial court ordered the parties to conduct depositions on the Frye
issue. Thereafter, the parties briefed and argued the issues. On October 5,
2016, the trial court granted the Defendants’ Frye motions and precluded the
testimony of Executor’s experts. Since Executor could not prove the requisite
causation without the expert testimony, the parties stipulated to the entry of
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2 The remaining Defendants are BASF Corp.; Dow Agrosciences, LLC; John Deere Landscaping, Inc. (successor to Lesco, Inc.); Monsanto Company; Syngenta Crop Protection, Inc.; and the Bayer Defendants (Bayer Corp. d/b/a Bayer Cropscience, L.P., Bayer Cropscience Holding, Inc., Bayer Cropscience, L.P., Bayer Cropscience Holding, Inc., in their own right.
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the October 14, 2016 order granting summary judgment, preserving all rights
to appeal the Frye determination.
Executor filed the within appeal on November 3, 2016, and timely
complied with the court’s order to file a Pa.R.A.P. 1925(b) concise statement
of errors complained of on appeal. The trial court issued a supplemental
memorandum. Executor presents one issue for our review: “Did the Plaintiff’s
experts employ generally accepted scientific methodology in arriving at their
opinions concerning medical causation in this toxic tort claim?” Appellant’s
brief at 4.
Although the appeal herein lies from the entry of summary judgment,
the appropriate appellate standard of review is the one pertaining to the
underlying ruling that Appellant is challenging. See K.H. v. J.R., 826 A.2d
863, 870-71 (Pa. 2003). Since the correctness of the Frye evidentiary ruling
is at issue herein, the abuse of discretion standard applies. Betz v. Pneumo
Abex LLC, 44 A.3d 27, 54 (Pa. 2012). “[A]n abuse of discretion may not be
found merely because an appellate court might have reached a different
conclusion, but requires a result of manifest unreasonableness, or partiality,
prejudice, bias, or ill-will, or such lack of support so as to be clearly
erroneous.” Id. at 45.
At issue in the underlying litigation is whether Decedent’s forty-year
occupational exposure to Defendants’ insecticides and fungicides, collectively
pesticides, some of which contain known carcinogens and teratogens, was a
substantial contributing factor in his death due to AML. The precise issue
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before us involves the propriety of the trial court’s ruling that Frye barred
Executor’s experts from testifying as to causation.
The Frye standard originally was intended to prevent the situation in
which a party would seek to introduce scientific evidence that was so new that
it would be impossible to “produce rebuttal experts, equally conversant with
the mechanics and methods of a particular technique.” United States v.
Addison, 498 F.2d 741, 744 (D.C. App. 1974). Frye contemplated a judicial
inquiry, informed by experts, into the general acceptance of the scientific
methods used. The standard required that “the thing from which the
[expert’s] deduction is made must be sufficiently established to have gained
general acceptance in the particular field in which it belongs.” Frye, supra
at 1014. At issue in Frye was admissibility of the systolic blood pressure
deception test, commonly known as the lie detector test. The trial court
excluded the evidence, and the court affirmed that ruling on appeal,
explaining:
Just when a scientific principle or discovery crosses the line between the experimental and demonstrable stages is difficult to define. Somewhere in this twilight zone the evidential force of the principle must be recognized, and while courts will go a long way in admitting expert testimony deduced from a well-recognized scientific principle or discovery, the thing from which the deduction is made must be sufficiently established to have gained general acceptance in the particular field in which it belongs.
Frye, supra at 1014. Pennsylvania adopted the Frye standard in
Commonwealth v. Topa, 369 A.2d 1277 (Pa. 1977), a case involving the
propriety of the trial court’s admission of voice print identification evidence
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through an expert, Lieutenant Nash, of the Michigan State Police. Our High
Court, applying Frye, reasoned that
[t]he requirement of general acceptance in the scientific community assures that those most qualified to assess the general validity of a scientific method will have the determinative voice. Additionally, the Frye test protects prosecution and defense alike by assuring that a minimal reserve of experts exists who can critically examine the validity of a scientific determination in a particular case. Since scientific proof may in some instances assume a posture of mystic infallibility in the eyes of a jury of laymen, the ability to produce rebuttal experts, equally conversant with the mechanics and methods of a particular technique, may prove to be essential.
Topa, supra at 1282 (quoting Addison, supra at 744). The Topa Court
went on to conclude that the testimony of one expert could not satisfy this
standard, citing commentaries questioning the reliability of sound
spectrographs and voiceprints and demonstrating that it was not generally
accepted within the field of acoustical science.
Thus, the Frye standard originally was intended to prevent a party from
introducing scientific evidence that was so new that it would be impossible to
“produce rebuttal experts, equally conversant with the mechanics and
methods of a particular technique.” Addison, supra at 744. 498 F.2d 741,
744 (D.C. App. 1974). Frye contemplated a judicial inquiry, informed by
experts, into the general acceptance of the scientific methods used.
In the years since the adoption of the Frye standard, this Court has
clarified that “Frye only applies to determine if the relevant scientific
community has generally accepted the principles and methodology the
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scientist employs, not the conclusions the scientist reaches.” Trach v. Fellin,
817 A.2d 1102, 1112 (Pa.Super. 2003) (en banc). The Frye test has been
incorporated into Pennsylvania Rule of Evidence 702, which provides:
A witness who is qualified as an expert by knowledge, skill, experience, training, or education may testify in the form of an opinion or otherwise if:
(a) The expert’s scientific, technical, or other specialized knowledge is beyond that possessed by the average layperson;
(b) The expert’s scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue;
(c) The expert’s methodology is generally accepted in the relevant field.
Pa.R.E. 702 (emphasis added).
Executor contends first that a Frye inquiry was not indicated on two
grounds: 1) the causal link between pesticides and leukemia is not novel
science; and 2) it is inapplicable where a medical expert reviews medical
records and arrives at conclusions regarding the source of injuries. See
Cummins v. Rosa, 846 A.2d 148 (Pa. 2004), Trach, supra, and Tucker v.
Community Medical Center, 833 A.2d 217, 224 (Pa.Super. 2003).
In anticipation that we might conclude otherwise, Executor argues in the
alternative that his experts satisfied Frye’s generally-accepted-methodology
requirement for the admissibility of novel scientific evidence. His experts, Drs.
Brautbar and Zambelli-Weiner, applied the generally accepted Bradford Hill
viewpoints for establishing general causation. Dr. Brautbar also applied
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differential diagnosis, a generally accepted methodology, in arriving at his
specific causation opinions.
Executor alleges further that the trial court violated Pa.R.C.P. 207.1 and
Grady v. Frito Lay, 839 A.2d 1038 (Pa. 2003), by looking at the experts’
conclusions rather than the general acceptability of their methodologies within
the relevant scientific communities. He maintains that the court found the
experts’ methodologies unreliable simply because the experts’ conclusions did
not match those of the study authors cited. In arriving at its conclusions,
Executor contends that the trial court “delved into an area beyond the training
and experience of judges and lawyers, and substituted its analysis of the
scientific literature for the analysis that was conducted by [Executor’s]
experts.” Appellant’s brief at 17. In doing so, according to Executor, the court
improperly focused on the conclusions reached, rather than on whether the
principles and methodology were generally accepted. In addition, the court
improperly demanded indisputable evidence of the link between pesticide
exposure and AML.
We find considerable support for Executor’s position that the link
between pesticides and cancer has crossed the threshold from novel to general
acceptance. The record reveals that more than 700 articles and studies have
been published examining the connection. See Betz v. Pneumo Abex LLC,
44 A.3d 27 (Pa. 2012) (noting link between asbestos and mesothelioma not
novel science as studies went back to 1935). However, the Betz Court
recently clarified that a “reasonably broad meaning should be ascribed to the
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term ‘novel,’” and expanded Frye to require a hearing when a trial judge has
“articulable grounds to believe that an expert has not applied accepted
scientific methodology in a conventional fashion in reaching his conclusions.”
Id. at 545. Since the defense offered expert opinion that neither Dr. Brautbar
nor Dr. Zambelli-Weiner applied the Bradford-Hill method in a generally
accepted manner in reaching their conclusions, we find no abuse of discretion
on the part of the trial court in conducting a Frye inquiry herein.
Nonetheless, we find merit in Executor’s contention that the Frye
inquiry herein was overly expansive. The court viewed its role as that of a
gatekeeper, charged with “review[ing] the studies that Dr. Brautbar relies
upon to determine whether they support Dr. Brautbar’s reliance[,]” and “to
make sure that the articles stood for what Dr. Brautbar said that they did.”
Supplemental Memorandum, 12/27/16, at 5. That is not the proper role of
the trial court in a Frye inquiry.
Frye requires that a proponent of novel scientific testimony
demonstrate that the expert relied upon and conventionally applied a scientific
method generally accepted in the relevant scientific community. Both Dr.
Brautbar and Dr. Zambelli-Weiner used the Bradford Hill criteria, which the
defense agreed was a generally accepted scientific methodology for
determining general causation. In fact, defense expert David H. Garabrant,
M.D., used the same method. See Expert report of David H. Garabrant, M.D.,
at 7 (“My opinions regarding the causal relationship between exposure to
pesticides and risk of AML are based on the causal considerations laid out by
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Austin Bradford Hill”). Even the trial court approved of Dr. Brautbar and Dr.
Zambelli-Weiner’s use of the Bradford Hill criteria. Supplemental Opinion,
12/27/16, at 5. The method identifies nine non-exclusive criteria relevant to
such a determination, one of which is the experimental data.3 Dr. Brautbar
explained how he analyzed those nine factors in arriving at his general
causation opinions. Although the defense experts maintained that Executor’s
experts did not correctly apply the Bradford Hill criteria, they offered little or
no insight as to why the approach was unconventional. They largely disagreed
with the weight the experts assigned to various factors and the conclusions
reached, neither of which would preclude the experts from testifying.
The trial court did not expressly find that Dr. Brautbar’s manner of
applying Bradford Hill was not generally accepted. Rather, the court focused
on Dr. Brautbar’s reference to studies in applying those factors, and concluded
that his reliance upon particular studies was not in accordance with generally
accepted scientific methodology. In arriving at that conclusion, the court
scrutinized the studies cited by Dr. Brautbar, assessed their scientific
relevance and validity, and then arrived at its own conclusion whether the
expert’s reliance upon them was scientifically acceptable. The court’s finding
that Dr. Brautbar did not follow accepted methodologies in relying upon
certain studies in forming his opinions as to general causation added another ____________________________________________
3 The Bradford Hill factors include the consistency, strength, specificity, and temporal relationship of the observed association; the biological plausibility of the exposure-response relationship, as well as the biological plausibility as viewed from data; coherence; experimental evidence; and analogy.
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layer to the generally accepted methodology requirement. Furthermore, the
trial court did not identify the methodology it was employing or reference
testimony from scientists in the field. In short, the trial court baldly concluded,
“Dr. Brautbar’s reliance on this literature to support his general causation
theory is not in accordance with generally acceptable scientific methodology.”4
Trial Court Opinion, 10/5/16, at 6.
The trial court employed the same flawed approach in evaluating the
sources reviewed and cited by Dr. Brautbar in support of his specific causation
opinions. Notably, the defense experts did not dispute the general acceptance
of Dr. Brautbar’s choice of the differential etiology methodology5 for
determining specific causation. That method permits a medical expert to
render specific causation opinions based on the scientific information
available, the patient’s history, his education, training, and experience. We
routinely require our experts, especially medical experts, to apply their
scientific knowledge, information, and expertise to a unique set of
4 Dr. Brautbar also referred to the Material Safety Data Sheets (“MSDSs”), documents containing information on the potential hazards of the individual products, in arriving at his general causation opinions.
5 Dr. Brautbar explained that, in this case, the differential etiology method involved “ruling in all identifiable causes of (and risk factors for) acute myelogenous leukemia and then ruling out those for which there is inadequate evidence.” Dr. Brautbar Expert Report, at 61. He found Decedent’s medical history to be negative for congenital disorders, hematologic disorders, exposure to chemotherapy, radiation, or cigarette smoking, and ruled out substantial exposure to petroleum products or pesticides prior to his forty- year employment at golf courses.
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circumstances. The fact that the experts arrive at different conclusions goes
to the weight of the evidence, not to its admissibility.
The court looked behind Dr. Brautbar’s differential diagnosis
methodology and challenged his conclusion that chromosomal abnormalities
in chromosomes 5 and 7 constituted strong evidence that Mr. Walsh’s AML
was caused by benzene exposure. The court noted that, while the studies
upon which Dr. Brautbar relied found a higher incidence of such aberrations
with chemical exposure, the aberrations were not conclusively linked to such
exposure. Furthermore, the court went on to opine, again without citing any
scientific support, that each of the following was scientifically unacceptable.
1. “to use a study of bovine lymphocyte cultures as a basis for concluding that exposure to Touche causes AML in humans.” Trial Court Opinion, 10/5/16, at 10.
2. “to use a study of mice bone marrow as a basis for concluding that exposure to Roundup causes AML in humans.” Id. at 11.
3. To rely upon animal studies, test-tube studies, and studies that include significant limiting language as to the applicability of their results to causation theories. Id. at 12.
4. To select portions of studies that favor a certain outcome while ignoring direct statements against that outcome contained within the same article.” Id. at 12-13.
5. To rely on sources “predicting risk and establishing causation” as they “do not go hand-in-hand.” Id. at 3.
As the foregoing conclusions illustrate, the trial court applied its own
view of what studies were scientifically/medically acceptable to support the
expert’s opinion. In doing so, the trial court impermissibly set itself up “as a
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super expert in the field of medicine.” Kubacki v. Metropolitan Life Ins.
Co., 164 A.2d 48, 52 (Pa.Super. 1960). That was not its role under Frye.
The purpose of a Frye hearing is to permit a trial court to hear from
experts in the relevant scientific field whether an expert’s methodology is
generally accepted.6 As our Supreme Court acknowledged in Grady v. Frito
Lay, Inc., 839 A.2d 1038, 1044 (Pa. 2003), “one of the primary reasons we
embraced the Frye test in Topa was its assurance that judges would be
guided by scientists when assessing the reliability of a scientific method.” The
Court added, that “[g]iven the ever-increasing complexity of scientific
advances, this assurance is at least as compelling today as it was in 1977[.]”
Id. at 1045. The Grady Court concluded that, “requiring judges to pay
deference to the conclusions of those who are in the best position to evaluate
the merits of scientific theory and technique when ruling on the admissibility
of scientific proof, as the Frye rule requires, is the better way of insuring that
only reliable expert scientific evidence is admitted at trial.” Id.
Nor is an expert required to parrot the conclusions of study authors. As
Justice Castille cautioned in his dissent in Blum v. Merrell Dow Pharms.,
Inc., 764 A.2d 1, 15 (Pa. 2000), limiting an expert to the conclusions reached
6 In lieu of a Frye hearing, the court ordered that depositions be taken of the experts. Thereafter, the parties briefed and argued the merits of their respective Frye positions. There is no indication that the trial court relied upon the deposition testimony in arriving at its conclusions regarding generally accepted scientific methodologies.
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by a study is a narrow approach that “conclusively determines that no opinion
other than the initial researcher’s may ever be heard.” He maintained that
we must allow room for expert medical opinion based on generally accepted
scientific principles.
In support of the trial court’s Frye determination, Defendant Dow
Agrosciences contends that “any methodology based on ‘pesticides’ as a class,
and/or ‘chromosomal aberrations’ and cancer generally, involves too great of
an analytical leap to support admissible medical causation expert opinions” for
the products at issue. Brief of Dow Agrosciences at 30. Dow maintains that
Executor failed to submit epidemiology evidence supporting a specific link
between its product, Dursban, and AML, and asserts that there are no studies
demonstrating a connection.7 It contends that Dr. Brautbar failed to consider
alternative causes of AML for purposes of differential diagnosis, such as his
obesity. Thus, it contends, the trial court was correct in precluding the experts
under Frye.
Deere & Company (“Deere”), the producer of Manicure, similarly alleges
that “Dr. Brautbar relies on mechanistic laboratory testing for his opinions[,]”
but failed to reference tests specific to whether Deere’s product, or what
7 The record contains references to a 2004 peer-reviewed article discussing adverse health effects among occupational users of Chlorphyrifos, the active ingredient in Dursban. The authors of that article link Chlorphyrifos, an organophosphate, to an increased risk of developing leukemia. Dursban also contains petroleum solvents that are alleged to contain benzene, a known carcinogen linked with AML.
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dosage of its product, could cause AML. It criticizes Dr. Brautbar’s
methodology because he did not reference epidemiology studies involving
Chlorothalonil, a chemical in Manicure, which did not reveal a statistically
significant risk for leukemia. Deere alleges that the experts’ failure to address
such studies “shows gaps in their methodology.” Deere’s brief at 6.
Furthermore, Deere argues that Dr. Brautbar’s reliance upon animal and in
vitro studies instead of the epidemiology studies involving humans is
inappropriate. BASF Corporation makes similar arguments with relation to its
product Touche’ and its active ingredient, vinclozolin.
We glean the following from the record. Scientists routinely perform
animal and in vitro studies, as is evident from the number of such studies
undertaken. Dr. Brautbar did not rely solely on such studies. Dr. Brautbar
also relied upon case studies involving farmers, golf course superintendents,
workers, and pesticide applicators exposed to occupational pesticides. In
addition, his opinions were informed by cytogenetic studies linking certain
genetic deletions with exposure to chemicals, together with his own
knowledge, education, and experience as a physician.
Although the epidemiological studies cited by Executor’s experts did not
explore whether exposure to one particular pesticide product caused AML, we
reject Defendants’ contention that such specific studies were required in order
to survive a Frye scrutiny. The EPA assesses the cumulative risk of pesticides
that share common mechanisms of toxicity or act the same way in the body.
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Scientists have looked at multiple pesticide exposures in agricultural and
manufacturing settings, which one could argue provides a more accurate
picture of occupational exposure. Executor’s epidemiological expert, Dr.
Zambelli-Weiner, explained that most epidemiological studies examine the
effects of multiple pesticide exposures because they are additive, cumulative,
and synergistic. She concluded that epidemiological studies that have
examined the association between pesticide exposure and leukemia risk have
consistently shown a positive association, some estimates demonstrating a
two-fold increase in risk. She opined, to a reasonable degree of scientific
certainty, that “organophosphate pesticide formulations, individually or in
combination, [are] causally related to an increased risk of leukemia in humans
exposed to them.” Zambelli-Weiner Report, 7/18/12, at 15. She opined
further that, “[e]pidemiologic studies support at least an additive effect on
risk of leukemia based on the independent effects of multiple pesticide
formulations including exposure to solvents.” Id. at 14.
Thus, the scientific literature, in the aggregate, supports a causal
relationship between long-term pesticide exposure and leukemia, such as
AML. That link is not a mere scientific hunch. For purposes of Frye, an expert
need not rely on studies that mirror the exact facts under consideration. It is
sufficient if the synthesis of various legitimate studies reasonably permits the
conclusion reached by the expert. The absence of a treatise or study directly
on point goes to the weight, not the admissibility, of expert opinion. An
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expert’s opinion will satisfy Frye when it is deduced from generally accepted
scientific principles and supported by studies or literature, even where the
expert could not point to one study involving parallel circumstances.
The general scientific principle underlying the opinions of Dr. Zambelli-
Weiner and Dr. Brautbar is that long-term exposure to pesticides can cause
or increase the risk of leukemia, and specifically AML. The literature and
studies, in the aggregate, support the general acceptance of that principle. In
addition, medical science in the form of cytogenetic studies linking changes in
certain chromosomes with exposure to chemicals supports a causal link.8 Dr.
Brautbar used the differential diagnosis theory, which is generally accepted in
the scientific community, to arrive at his opinion that long-term pesticide
exposure was the cause of Decedent’s AML. See In re Paoli R.R. Yard PCB
Litig., 35 F.3d 717, 756 (3d Cir. 1994) (affirming for purposes of the Frye
prong of the Daubert inquiry, that differential diagnosis is widely accepted
technique, subjected to peer review, used by the medical community to rule
in or out alternative causes).
Defendants focus herein on the expert physician Dr. Brautbar’s inability
to quantify Mr. Walsh’s exposure to each specific product and to opine that
each of those exposure levels significantly or substantially increased the risk
8 Although the trial court dismissed the cytogenetic studies as they were not conclusive, we find the existence of those studies, together with the differential etiology methodology employed by Dr. Brautbar, sufficient to pass muster under Frye.
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of AML. That is not the proper subject for a Frye inquiry. An expert’s ability
to opine with a reasonable degree of scientific or medical certainty that
exposure to a particular defective product substantially caused or contributed
to the injury goes to the legal sufficiency of the expert testimony, not to
whether the science is generally accepted.9 Summary judgment, not Frye, is
the appropriate vehicle for addressing that question.10 See Howard v. A.W.
Chesterton Co., 78 A.3d 605, 607-08 (Pa. 2013) (per curiam).
Our decision is in accord with Trach, supra at 1104, holding that since
Frye is an exclusionary rule of evidence, “it must be construed narrowly so as
not to impede admissibility of evidence that will aid the trier of fact in the
search for truth.” For these reasons, we vacate both the order excluding
Executor’s experts from testifying, and the subsequent order granting
summary judgment in favor of Defendants based on that prior order, and
remand for further proceedings consistent with this memorandum.
9 Defendants’ focus on substantial factor and the “one breath” theory to preclude Executors’ expert opinions under Frye is misplaced. The record establishes frequent, regular, and proximate exposure to the pesticides at issue herein. Dr. Brautbar relied upon that exposure history, together with Decedent’s medical history, epidemiological studies, and cytogenetic studies, in arriving at his conclusion that Decedent’s forty-year exposure to Defendants’ pesticides caused or contributed to his death from AML.
10 Prior to the Frye challenge, summary judgment was granted in favor of several of the original defendants due to a lack of expert testimony identifying their products as substantial contributing factors in Mr. Walsh’s death. As to the Defendants remaining herein, the expert proof was sufficient to survive that scrutiny.
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Orders vacated and case remanded for further proceedings. Jurisdiction
relinquished.
Judge Strassburger joins the memorandum.
President Judge Emeritus Bender files a dissenting memorandum.
Judgment Entered.
Joseph D. Seletyn, Esq. Prothonotary
Date: 5/22/2018
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