Toxicology Expert’s Opinions Properly Excluded for Failure to Consider Dose-Response Relationship or Potential Alternative Causes of Plaintiff’s Disease

In Williams v. Mosaic Fertilizer, LLC, 2018 WL 2191426 (11th Cir. May 14, 2018), the Eleventh Circuit affirmed the District Court’s exclusion of proffered expert testimony by a toxicologist, and of the plaintiff’s proposed lay testimony that her home had “no present value” because of emissions from a nearby fertilizer plant, and affirmed the resulting grant of summary judgment to the defendant.

Plaintiff Rhonda Williams has always lived in Tampa, Florida, about three miles away from the defendant’s fertilizer plant. She suffers from pulmonary hypertension, diabetes, and other health conditions, as well as side effects from treatment of those conditions, and she alleged in her state-court complaint that emissions from the defendant’s plant caused, contributed to, or exacerbated her health problems. She relied on the report of Dr. Mink, a toxicologist, to establish general and specific causation, and she offered her own testimony that her house had “no present value” because of the presence of pollutants emitted from the plant.

The defendant removed the case to federal court and later moved to exclude Dr. Mink’s testimony and the plaintiff’s valuation testimony, and for summary judgment. The district court, without conducting a Daubert hearing, granted all three of the motions.

The Eleventh Circuit, in an opinion written by Judge Tjoflat and joined by Judge Rosenbaum and Judge Ungaro visiting from the Southern District of Florida, affirmed. As to the exclusion of Dr. Mink’s testimony, the court noted both the district court’s “gatekeeper” responsibility under Daubert and Kumho’s reminder that “[t]he trial judge must have considerable leeway in deciding in a particular case how to go about determining whether particular expert testimony is reliable.” The court also highlighted the district court’s comprehensive analysis of the proffered testimony and its identification of “multiple defects” in Mink’s testimony.

Those defects, the court continued, including Mink’s “failure to properly assess dose-response. . . [which] is the hallmark of basic toxicology.” Mink did not perform a dose calculation specific to the plaintiff, and the studies on which he claimed to have relied reported that fertilizer plants made a “minor contribution” to the ambient levels of the chemicals at issue and thus contradicted Mink’s opinions. And even if Mink had come up with sound dosage estimates, “he failed to demonstrate a scientific basis for concluding that those exposure levels would likely produce, contribute to, or exacerbate” the plaintiff’s conditions. Mink cited past measurements showing that the plant’s emissions exceeded the National Ambient Air Quality Standard (“NAAQS”) set by the EPA, but failed to account for the fact that those standards serve a different purpose than dose-response calculations: “regulatory standards often build in considerable cushion[.]” Thus even though the court “ha[s] never required an expert to ‘give precise numbers about a dose-response relationship,’” the district court did not err in finding Mink’s consideration of dose-response insufficient.

The court also noted Mink’s failure to rule out other potential causes for plaintiff’s health problems—his deposition testimony that the probability of other causes was “low,” without identification of any scientific basis for that opinion, was insufficient—and his failure to consider the background risk of the health problems at issue. “Dr. Mink failed to meaningfully address other potential causes of Ms. Williams’ conditions or even the background risk of those conditions. This fundamental methodological failure undermined the soundness of his causation opinions, and the District Court was therefore right to exclude those opinions as unsound.”

The court also affirmed the exclusion of plaintiff’s testimony that her house had “no present value” because of its proximity to the defendant’s plant. While the owner of property is generally competent to testify as to its value, the plaintiff’s testimony in this case, offered without any foundation (testimony about appraisals or attempted sale, for instance) and in the face of contradictory evidence (establishing recent sales in the neighborhood) was “pure speculation.”

Posted by Valerie Sanders.

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