The Causal Conundrum: Examining the Medical-legal Disconnect in Toxic Tort Cases from a Cultural Perspective or How the Law Swallowed the Epidemiologist and Grew Long Legs and a Tail

• Publication year: 2022

51 Creighton L. Rev. 319. THE CAUSAL CONUNDRUM: EXAMINING THE MEDICAL-LEGAL DISCONNECT IN TOXIC TORT CASES FROM A CULTURAL PERSPECTIVE OR HOW THE LAW SWALLOWED THE EPIDEMIOLOGIST AND GREW LONG LEGS AND A TAIL

THE CAUSAL CONUNDRUM: EXAMINING THE MEDICAL-LEGAL DISCONNECT IN TOXIC TORT CASES FROM A CULTURAL PERSPECTIVE OR HOW THE LAW SWALLOWED THE EPIDEMIOLOGIST AND GREW LONG LEGS AND A TAIL

Barbara Pfeffer Billauer(fn*)

ABSTRACT:

The literature regarding the law-epidemiologic disconnect in causal proof is vast, non-conclusive and partisan. Some favor weakening the plaintiffs burden in cases of ambiguous causation (when we do not have enough objective scientific proof), even if bastardizing scientific requisites is necessary. Scientific purists, of course, object. Some suggest crafting novel legal causes of action, such as proportionate liability. Legal purists reject this approach. The conflict has been raging for decades and we are no closer to resolving the issue than when it was first raised some thirty years ago.

This research takes a novel approach at resolving the dilemma, trying to understand the divide from a cultural, or "poetics," perspective before even attempting to reconcile the disconnect. After discussing five conflicting decisions reaching contrary scientific conclusions regarding 'specific' and 'general' causation, and different legal resolutions regarding admissibility of expert testimony, I set forth a detailed discussion of the elements of "poetics," a method of examining how meanings get mangled across the communication divide. Using this methodology, I examine the cultural and linguistic dissonance of tort law and science. Then, with these tools in hand, I re-visit the poetics of law, epidemiology, and medicine, only to discover not only "poetic failure" among the three disciplines, but internal discord within the field of epidemiology itself. Exposing these faults within the foundational underpinnings of epidemiology highlights difficulties faced by the field, which, when incorporated into legal discourse, compromises legal outcomes. Once the flaws were exposed, options for legally reliable and scientifically valid resolution became apparent.

However, not until courts appreciate the inherent discord within epidemiology itself and the resultant limitations in addressing multi-causation, will we reach a point where far-reaching resolution is even on the event horizon, and we are doomed to generating ever conflicting opinions.

I. INTRODUCTION

[I]t would be a dangerous undertaking for persons trained only to the law to constitute themselves the final judges of the worth of [a work], outside of the narrowest and most obvious limits.(fn1)

-Oliver Wendell Holmes Rudyard Kipling's Just So Stories have the theme of a particular animal being modified from its original form to its current state by acts of humans or some magical being. No description could come closer to the morphed state epidemiology has assumed in legal parlance than the narrative of Kipling's How the Kangaroo Got its Legs.(fn2)

To paraphrase Kipling's opening lines,(fn3) "Not always was the Epidemiologist as now we do behold him, but a different animal with four long legs and a long tail."(fn4) The statement is apt. Tail is an epidemiological term that refers to the skewness of a population distribution; if the test population is not normally distributed, it provides a poor basis for extrapolation, either to the plaintiff or the public. Long legs is a colloquial term referring to staying power, such as the hold the present application of epidemiology has had on legal causation, even when perhaps it is unsuited for the task.

Kipling's story ends with the following verse, eerily foreshadowing problems inherent in proving legal culpability: "So they were left in the middle of Australia, Old Man Kangaroo and Yellow-Dog Dingo, and each said, 'That's your fault.'"(fn5)

II. BACKGROUND

Numerous attempts at reconciling disconnects between epidemiologic and legal proof have been attempted(fn6) and proven wanting.(fn7) Some commentators have "reconfigured science" for legal use, or diluted conventionally accepted scientific standards to ease the plaintiffs burden(fn8) where traditional scientific proof is unavailable.(fn9) These approaches have been met with resistance by purists of both the scientific and legal professions.(fn10)

Before trying to resolve problems in "causal ambiguity" (which I define as instances when enough definitive science to meet current legal standards is unavailable),(fn11) I attempt to understand the medico-legal divide using a novel approach, assessing the issue from a cultural perspective. In so doing, I propose that the causal conundrum arises from dissimilar histories, linguistic misunderstandings and cultural conflicts. Using case studies and a comparative discipline analysis, I demonstrate a cultural and linguistic mismatch, a "poetic failure"(fn12) between the disciplines. In other words, judges, lawyers, clinicians (treating physicians) and epidemiologists simply do not understand each other, not surprisingly generating confusion and legal conflicts.

Instead of crafting an artificial middle ground or imposing additional obstacles to address perceived scientific deficiencies,(fn13) I suggest that resolving the issue first requires recognizing the impasse. Further, I suggest that the clinician's view of epidemiology is far different than, and perhaps more relevant to, proving legal causation than the current "public-health epidemiology" paradigm.(fn14) I begin the inquiry with a case-study analysis of five cases.

A. SPECIFIC V. GENERAL CAUSATION: WHY DO THE RESULTS DIFFER SO?

In the pivotal case of Parker v. Mobil Oil Corp.,(fn15) the New York Court of Appeals held that the factors needed to prove causation in toxic tort cases(fn16) are: (1) exposure, (2) general causation,(fn17) and (3) specific causation.(fn18) Exposure addresses whether the amount of toxin to which the plaintiff was exposed(fn19) was sufficient to cause the disease in question,(fn20) a standard arising as early as 1988.(fn21) General causation asks whether a substance can cause the disease. Specific causation(fn22) asks whether the substance did cause the disease in this plaintiff,(fn23) seemingly simple issues to understand,(fn24) if not prove.

This three-fold legal inquiry has international acceptance.(fn25) Nevertheless, individual court decisions appear outcome-determinative, societal expectations and outcry seem influential, and contradictions in conceptualization and understanding run rampant. The illustrative cases discussed in the next section, Parker, Milward v. Acuity Specialty Products Group Inc.,(fn26) the two Israeli Kishon cases, and the DuPont C-8 cases, highlight the confusion. The disparate results and reasoning are surely harbingers of United States Supreme Court intervention.

One issue driving the disparity emerges from the exposure element i.e., determining under which rubric we assess whether the plaintiff was sufficiently exposed. A second problem emerges from determining the competency of experts to testify, which drives the decision.(fn27) Thus, in comparison with medical malpractice cases where many states allow licensed physicians to testify regardless of specialty,(fn28) toxic tort cases are more restrictive.(fn29) Further, admissibility of epidemiological testimony on specific causation has proven difficult, mainly because of a misguided belief regarding its inapplicability to individual diagnosis misconceptions, which I demonstrate, were seeded by epidemiologists themselves.

1. Parker v. Mobil Oil Corp.

The Parker case concerned a gas station attendant who claimed his seventeen-year benzene exposure via gasoline inhalation caused his acute myelogenous leukemia ("AML").(fn30) The court ruled there is no dispute that benzene is a known carcinogen.(fn31) The issue, however, involved whether gasoline, a component of which is benzene, is carcinogenic because no significant association has been found between gasoline exposure and AML via epidemiologic study.(fn32) The court ruled that regulatory standards were inadequate to demonstrate legal causation,(fn33) did not allow extrapolation of the benzene studies(fn34) to gasoline-containing-benzene exposure,(fn35) and refused to acknowledge the possibility of synergism.(fn36)

Another key issue in Parker was lack of exposure measurement. Without curing this infirmity, the court ruled that specific causation could not be established.(fn37) Thus, the court rejected the plaintiffs expert vague exposure assessment(fn38) because his characterization was adjectival. The court held the words "frequently" and "excessive" were speculative,(fn39) not based on reliable methodology, and hence unscientific.(fn40) Although the court recognized alternative means of scientific exposure methods,(fn41) these were not used.

Thus, while the defendants' epidemiologist "acknowledged that there is an increased risk of AML for service station employees exposed to large amounts of benzene(fn42) over an extended period of time," he concluded that the low levels of benzene exposure typically resulting from gasoline service station work were "below the practical threshold for the dose necessary to initiate the leukemia process . . . ."

Nevertheless, the impact of the plaintiffs exposure to cigarettes (of which benzene is a component)(fn43) as adding to his benzene-burden was not raised or considered. Thus, the subsequent exposure to the benzene in the...