A legal malpractice case is the somewhat surprising setting for an interesting Daubert toxic tort opinion, but we found one. Young, et al. v. Burton, et al, 2008 WL 2810237 (D.D.C. 7/22/08).

Plaintiffs sued a law firm for allegedly failing to file a timely personal injury lawsuit for their alleged mold-induced injuries. The lawsuit would have sought recovery from a landlord for damages suffered by plaintiffs allegedly as a result of exposure to toxic mold while residing in a DC apartment building. In order to succeed on their legal malpractice claim, plaintiffs needed to show their underlying claim was meritorious. Thus, plaintiffs needed admissible expert testimony as to the cause, nature, and extent of their injuries.

Defendants moved to exclude the expert’s testimony, arguing that his opinions were not based on a reliable methodology.

Following a Daubert hearing, the Court concluded that the diagnosis of plaintiffs, as well as the proffered opinions relating to general and specific causation, were not sufficiently grounded in scientifically valid principles and methods to satisfy Daubert.

Exposure Claim

Plaintiffs resided in the apartment for approximately thirty-four days, during which time plaintiffs contend they could smell noxious fumes from raw sewage. They testified they noticed extensive visible mold growth in an adjacent vacant apartment, although they estimated they were in that apartment for no longer than one or two minutes. There was no documentation of any visible mold growth in plaintiffs’, and plaintiffs did not believe the two apartments shared a common air source.

Both plaintiffs submitted extensive medical records to document the health problems that they attribute to their mold exposure, but medical records also indicated significant medical problems prior to moving into the apartment

Plaintiffs’ expert, Dr. Shoemaker, used his own differential diagnostic procedure for mold illness. That procedure involves a two-tiered analysis. To satisfy the first tier, all three of the following factors must be met: (1) the potential for exposure; (2) the presence of a distinctive group of symptoms; and (3) the absence of confounding diagnoses and exposures. The second tier looks at levels of certain hormones and enzymes in the blood which the expert believes are altered by exposure to a biotoxin and thus serve as “biomarkers.”

Defense Argument

Defendants requested a Daubert hearing, arguing that there was no evidence as to the exact substance plaintiffs were exposed to or the level at which they were exposed, and thus formal toxicological causation analysis could not be performed. In addition, the tests Dr. Shoemaker used to reach his diagnosis are experimental and “not generally accepted in the toxicology community.” The traditional causation analysis, relying on the nine “Hill Criteria” that are necessary to establish a causal relationship, does not support a causal association between the dark material on the adjacent apartment walls and the plaintiffs’ health complaints. (In a nutshell, the Hill Criteria are: 1) strength; 2) consistency; 3) specificity; 4) temporality; 5) biological gradient; 6) plausibility; 7) coherence; 8) experiment; and 9) analogy).

Mold Disease Causation
Courts throughout the country have varied widely with respect to the level of certainty they require with respect to the issue of causation in mold cases. See Jeffrey J. Hayward, The Same Mold Story?: What Toxic Mold is Teaching us about Causation in Toxic Tort Litigation, 83 N.C. L.Rev. 518, 536-38 (2005). One common method of plaintiffs attempting to demonstrate causation is showing a temporal relationship between exposure to a toxin and subsequent adverse health effects. However, while necessary, temporal association between exposure and illness, without more, is generally insufficient to establish causation. Under the traditional approach, in the absence of an established scientific connection between exposure and illness, the temporal connection between exposure to chemicals and an onset of symptoms, standing alone, is entitled to little weight in determining causation.

The most widely-used method of demonstrating causation in toxic tort cases is to present scientifically accepted information about the dose-response curve for the toxin which confirms that the toxin can cause the health effects experienced by the plaintiff at the dosage plaintiff was exposed to. Indeed, scientific knowledge of the harmful level of exposure to a chemical, plus knowledge that the plaintiff was exposed to such quantities, are minimal facts necessary to sustain the plaintiff’s burden in a toxic tort case.

Diagnosis Flawed
Dr. Shoemaker could not show that plaintiffs met his own case definition. In the first tier of Dr. Shoemaker’s case definition, the patient must have had exposure; clearly, a person cannot be made ill by mold toxins to which she has not actually been exposed. No environmental tests were conducted in plaintiffs’ apartment to provide actual proof that plaintiffs did, in fact, inhale toxic substances when they resided there.

Shoemaker attempted to show that plaintiffs had the requisite exposure in two ways, neither of which was convincing to the court. First, Dr. Shoemaker believed that his case definition allowed him to use the diagnosis of the disease as evidence of actual exposure. In short, the symptoms fundamentally become the basis for explaining themselves. Such circular reasoning is not scientifically or medically acceptable. And factually, plaintiffs’ complex of symptoms did not begin immediately after exposure. Also, the symptoms did not remain consistent over time. Finally, Dr. Shoemaker was unable to determine which symptoms are actually attributable to the mold. Rather, he testified that roughly 75% of plaintiffs’ symptoms were probably attributable to this mold exposure, although he could not say which ones.

The third element of the first tier of Dr. Shoemaker’s diagnostic protocol is that there be an absence of confounding diagnoses and exposures. This requirement is critical to a differential diagnosis, which is to conclude that only the chosen diagnosis could be responsible for the symptoms presented. Nevertheless, Dr. Shoemaker glossed over the explanation of how he ruled out all potential confounding explanations for plaintiffs’ symptoms. At points, Dr. Shoemaker brushed off discussion of confounding diagnoses as almost irrelevant.

The most fundamental flaw in Dr. Shoemaker’s Tier 2 analysis was that not one of his biomarker tests is generally accepted or clinically validated for the purpose of diagnosing “mold illness.” Additionally, the idea that levels of these biomarkers five years after an exposure is in any way related to that exposure is unsupported by generally accepted science.

General Causation

Shoemaker arrived at his opinions on general and specific causation based on novel and unaccepted theories and methodologies. Plaintiffs’ general causation evidence confronted the problem that there was no way of knowing what substance the plaintiffs were in fact exposed to, as Dr. Shoemaker freely admitted he did not know what molds or bacteria were present in plaintiffs’ apartment. Second, his own peer-reviewed publication on “mold illness” was far too limited to stand alone as proof of general causation; only twenty-six subjects participated in the study, and the double-blinded, placebo-controlled clinical trial involved only thirteen of those subjects.

Specific Causation

On specific causation, in short, Shoemaker did not perform his five-step protocol on plaintiffs, and indeed could not possibly have done so, as he first met them long after they left the suspected mold environment. Nor was he able to base his causation opinion on the plaintiffs’ response to treatment, for both plaintiffs chose not to take the medication that he had prescribed for them.

Defendants did an outstanding job of holding plaintiff’s expert to the standards he himself created, but could not attain.