Pennsylvania Superior Court Reverses Trial Court’s Decision to Dismiss Suit Based on Junk Science

Pennsylvania Superior Court Reverses Trial Court’s Decision to Dismiss Suit Based on Junk Science

Recently, in the case of Walsh v. Bayer, et al., the Pennsylvania Superior Court analyzed a trial court’s dismissal of a “junk science” claim in connection with its application of Frye v. United States, 293 F. 1013 (D.C. Cir. 1923). Specifically, at issue was whether Mr. Thomas J. Walsh’s forty-year occupational exposure to defendants’ pesticides, some of which contain known carcinogens and teratogens, was a substantial contributing factor in his death due to Acute Myelogenous Leukemia (“AML”).

Mr. Walsh was employed for almost 40 years as a groundskeeper and golf course superintendent at several golf courses in the Pittsburgh area. During his employment, he frequently and regularly applied 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 coworker offered specific details about how the two men applied the pesticides, what pesticides were used, in what concentrations and the protective gear worn.

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 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 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.”

Wrongful death and survival action were initiated against the manufacturers of various pesticides that Mr. Walsh applied over the forty-year period, asserting claims in strict products liability, negligence, and breach of warranty. Plaintiff’s experts testified 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 that organophosphate pesticide formulations, individually or in combination, [are] causally related to an increased risk of leukemia in humans exposed to them. The defendants filed a “Frye” motion to exclude plaintiff’s experts, from testifying at trial, arguing that the methodologies used by these experts were not generally accepted or conventionally applied in the relevant scientific communities. After reviewing the depositions of the experts and the parties’ briefs, the trial court granted the defendants’ Frye motions and precluded the testimony of Executor’s experts, effectively dismissing the case.

According to the Superior Court, Frye contemplates a judicial inquiry, informed by experts, into the general acceptance of the scientific methods used, not the conclusions reached by the experts. In this case, the Superior Court found considerable support (over 700 articles) for plaintiff’s position that the link between pesticides and cancer has crossed the threshold from novel to general acceptance. The Court highlighted that both the defendants and the trial court agreed that the “Bradford Hill” methodology that the plaintiff’s experts utilized was appropriate.

Here, the Superior Court found that the trial court scrutinized the studies cited by plaintiff’s experts, assessed their scientific relevance and validity, and then arrived at its own conclusion whether the expert’s reliance upon them was scientifically acceptable. In doing so, the Superior Court determined that the trial court impermissibly set itself up as a “super expert” in the field of medicine, which is beyond the purview of Frye. Instead, the Court found that the scientific literature, in the aggregate, supports a causal relationship between long-term pesticide exposure and leukemia, such as AML. Thus, the court held that 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 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 Court further held 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.” Therefore, the Court reversed the trial court’s decision and remanded for further proceedings.