Products Liability Law Daily Trial court overreached in excluding expert testimony linking pesticides to cancer
Wednesday, July 22, 2020

Trial court overreached in excluding expert testimony linking pesticides to cancer

By Pamela C. Maloney, J.D.

A Pennsylvania trial court substituted its judgment for that of experts in the field in excluding expert testimony on link between exposure and AML.

In rejecting as scientifically unreliable animal studies, test tube studies, and studies that included significant limiting language as to the applicability of their results to causation theories, which had been used by an expert testifying on behalf of grounds keeper who died after developing AML allegedly as a result of long-term exposure to pesticides, a trial court misapplied its role in evaluating the admissibility of expert testimony, the Pennsylvania Supreme Court ruled, affirming a decision of the superior court that reversed the trial court’s grant of summary judgment in favor of numerous pesticide manufacturers and remanded the case to the trial court for a review of the manufacturers’ Frye motions. The supreme court also clarified the superior court’s decision on product-specific causation (Walsh v. BASF Corp., July21, 2020, Donohoe, C.).

The decedent was employed for almost 40 years as a grounds keeper and golf course superintendent at several golf courses, during which he frequently and regularly applied insecticides and fungicides. After he was diagnosed with Acute Myelogenous Leukemia (AML), cytogenetic testing showed chromosomal aberrations consistent with secondary leukemias, which are linked to radiation, chemotherapy, or chemical exposure. Following his death, his executor filed a wrongful death and survival action against the manufacturers of various pesticides the decedent had used over the years, asserting claims of strict products liability, negligence, and breach of warranty. The trial court granted summary judgment in favor of many of the manufacturers and sellers of the allegedly defective pesticides, based on a lack of expert causation testimony, leaving 15 products in the lawsuit. The remaining pesticide manufacturers filed "Frye motions" to exclude the experts offered by the executor of the decedent’s estate. These were ultimately granted by the trial court. The parties then stipulated to the entry of an order granting summary judgment, preserving all rights to appeal the Frye determinations. On appeal, the Pennsylvania Superior Court reversed the grant of summary judgment in favor of manufacturers on the ground that the trial court erred in its application of the standard enunciated in Frye (see Products Liability Daily’s May 23, 2018 analysis). It vacated the order precluding the experts from testifying and remanded the case for further proceedings. This appeal by the manufacturers followed.

"Gatekeeper" role. The manufacturers challenged the superior court’s conclusion that, when evaluating scientific evidence under the Frye standard, trial courts were not permitted to act as "gatekeepers" to ensure the relevance and reliability of the scientific studies offered by those experts to support their opinions by scrutinizing whether those studies actually supported their opinions. In defining the role of the trial court in a Frye contest, the state supreme court noted that it was of no consequence whether that role was referred to as a gate keeper. Prior Frye decisions made it clear that the trial court’s role was strictly limited to determining whether the expert had applied a generally accepted scientific methodology to reach his or her scientific conclusions. In the case at bar, the trial court’s Frye inquiry was overly expansive, the supreme court concluded. For example, the trial court unilaterally and without citing any authority rejected as scientifically unacceptable animal studies, test tube studies, and studies that included significant limiting language as to the applicability of their results to causation theories. Whether these studies cited by one of the estate’s expert accorded with generally accepted methodology constituted a scientific judgment that must be guided by experts in the field, not by a trial court, the supreme court admonished.

In addition, the trial court’s rejection of the expert’s "fingerprint" conclusion, which differed from a prior study regarding the link between pesticides and the development of AML, failed to take into account the expert’s explanation for the difference between the findings of older studies and his study. In doing so, the trial court relied on its own analysis of the scientific studies proffered by the expert and not on a review of the methodology that the expert used in reaching his conclusion. Despite the fact that the manufacturers had raised the issue of whether the estate’s expert had applied a generally accepted methodology to arrive at his fingerprint conclusion, the trial court issued no rulings on any of the Frye challenges. Thus, the superior court’s decision to vacate the trial court’s summary judgment orders was affirmed and the case was remanded so that the issues relevant to the manufacturers’ Frye motions could be addressed.

Product-specific causation. The manufacturers also challenged the superior court’s finding that the estate’s experts could satisfy their burden under the Frye test by and through the unrestricted use of extrapolations, which, in effect, eliminated the estate’s burden to show product-specific causation of the deceased’s specific injury. According to the manufacturers, the superior court had held that if an expert could cite to literature suggesting that a class of products could cause a disease, then that expert had met the burden under Frye to show that any particular product in that class caused the disease, regardless of the diversity among the various types of products within that class. In rejecting this challenge, the state high court found that the superior court’s opinion had not "blessed" the unrestricted use of extrapolation in a substantial cause analysis, nor did the superior court’s opinion find that establishing a causal link between cancer and long-term exposure to pesticides was sufficient to support a causation decision regarding exposure to a specific manufacturer’s product, thereby eliminating a plaintiff’s burden to show product-specific causation. Instead, the superior court’s opinion properly indicated only that the absence of a treatise or study directly on point with regard to a specific product went to the weight, not the admissibility, of the expert’s testimony.

Concurrences/Dissents. Justice Wecht wrote a separate concurrence to address "problematic terminology" introduced into the Frye analysis by the Pennsylvania high court’s decision in Betz v. Pneumo Abex L.L.C., 44 A.3d 27 (Pa. 2012). Justice Baer also wrote separately to join the majority in remanding the case to the trial court with respect to the Frye challenges, but disagreed with the majority with regard to product-specific causation, agreeing with the dissent written by Chief Justice Saylor that the estate’s experts had engaged in improper extrapolation. According to the Chief Justice, although the majority deemed it inconsequential "whether or not this Court should denominate trial judges as gate keepers relative to the admission of novel scientific evidence in Pennsylvania courtrooms," this role was" the clear purport of most of this Court’s decisions on the subject."

The case is Nos. J-92A-2019, J-92B-2019, J-92C-2019, J-92D-2019 and J-92E-2019.

Attorneys: Michael Joseph D'Amico (D'Amico Law Offices, LLC) for Richard Thomas Walsh. Christopher D. Stofko (Dickie, McCamey&Chilcote, PC) for BASF Corp. Michael R. Borasky (Eckert Seamans Cherin& Mellott, LLC) and Robert L. Byer (Duane Morris LLP) for Bayer Corp. d/b/a Bayer Crop Science, L.P and Bayer Crop Science Holding, Inc.

Companies: BASF Corp.; Bayer Corp. d/b/a Bayer CropScience, LP; Bayer CropScience Holding, Inc.

MainStory: TopStory ExpertEvidenceNews CausationNews ChemicalNews PennsylvaniaNews

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