Walsh v. BASF Corporation Apl of: BASF

Rule of Law:

Under the Frye standard for the admissibility of expert scientific testimony in Pennsylvania, a trial court's role is strictly limited to determining whether the expert’s scientific methodology is generally accepted in the relevant field, and it may not scrutinize the reliability or factual support of the expert's conclusions or the underlying scientific literature.

Facts:

• Thomas J. Walsh worked for nearly forty years as a groundskeeper and golf course superintendent at several Pittsburgh area golf courses.
• Walsh's work involved the regular application of various pesticides, primarily insecticides and fungicides, on the golf courses.
• Walsh kept a detailed log of the specific pesticide products he used and the dates of their applications.
• Early in his career, Walsh used only gloves for protection, later adding overalls, rubber boots, and masks, and eventually disposable protective gear, but exposure to pesticide dust still occurred when opening bags and mixing chemicals.
• On October 5, 2008, Walsh was diagnosed with Acute Myelogenous Leukemia (AML) after presenting to an emergency room with fever, chills, and a cough.
• Cytogenetic testing performed on Walsh revealed significant chromosomal aberrations.
• Walsh died on February 2, 2009, and his treating oncologist opined that his extensive exposure to pesticides likely played a significant role in his AML.

Procedural Posture:

• Richard Thomas Walsh, Executor of the Estate of Thomas J. Walsh, commenced a wrongful death and survival action against numerous pesticide manufacturers in the Court of Common Pleas of Allegheny County (trial court).
• The trial court granted summary judgment in favor of a large number of manufacturers due to a perceived lack of expert testimony identifying various pesticides as substantial contributing factors to Walsh's death.
• Defendant manufacturers (including Bayer CropScience LP, Bayer Corporation, Bayer CropScience Holdings, Inc., and others) filed Frye motions to exclude the testimony of the Executor's expert witnesses, Dr. Brautbar and Dr. Zambelli-Weiner, alleging their methodologies were not generally accepted.
• The trial court, after depositions and briefs but without conducting a Frye hearing, granted the defendants' Frye motions.
• The trial court found that Dr. Brautbar’s expert report did not establish general or specific causation for non-benzene pesticides, and rejected specific causation for benzene-containing pesticides due to a lack of support for low-level exposure causing AML and its rejection of his 'fingerprint theory'.
• The trial court also concluded Dr. Zambelli-Weiner’s 'pesticides as a class' opinion was not in accordance with generally accepted scientific methodology and therefore immaterial.
• The parties stipulated to the entry of summary judgment in favor of all remaining defendants and against Walsh on all claims, preserving all rights of appeal.
• The Executor appealed to the Superior Court of Pennsylvania (intermediate appellate court).
• The Superior Court reversed the trial court’s grant of the Frye motions, ruling that the trial court had overstepped its 'gatekeeper' function by scrutinizing the scientific literature's reliability and factual support for the experts' conclusions, rather than solely the general acceptance of their methodology.
• Defendant manufacturers (Appellants) appealed the Superior Court's decision to the Supreme Court of Pennsylvania.