Multiple chemical sensibility in the courtroom: is there life after Daubert?

• Author: Berkowitz, Wendi J.

IS THERE anything new under the sun? Consider these excerpts:

An elderly neurologist in Marseilles told me about young Italian female patients, usually from southern Italy, who would be brought to his clinic .. in an ambulance, convulsing and thrashing in fits. "It would take four men to hold them down," he said. He cured them with sugar pills.(1)

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In every era, people have suffered varieties of symptoms not readily explained by "known" diseases of the day. To provide explanations and treatment approaches, individuals with symptom complexes were frequently provided a unifying disease label. At the turn of the 20th century, that label was autointoxication. Today, it is multiple chemical sensitivities (MCS). Autointoxication, a popular turn-of-the-century phenomenon[,] illustrates that absent common, reproducible, definable, and measurable findings and consistent, objective endpoints, newly named fad disorders have not survived long term. Autointoxication was a disorder very similar in manifestations to MCS. It was, we now know, a pseudo[-]disease, the treatment of which was based upon an unproved hypothesis. If MCS cannot withstand the probing of scientific investigation, it too will disappear as a diagnosis.(2)

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Clinical ecologists claim that various kinds of environmental insults may depress a person's immune system so that the exposed person develops a "multiple chemical sensitivity," that is, becomes hypersensitive to other chemicals and naturally occurring substances. According to this theory, not all persons will necessarily develop the same symptoms as a consequence of this hypersensitivity; each person exposed may present a distinctive profile.(3)

SEARCHING FOR MCS

Multiple chemical sensitivity (MCS) is a puzzling diagnosis. Its proponents believe that MCS results from chemical insult - almost any kind of chemical will do. What they cannot say is (1) what amount or concentration of a particular chemical, a mix of chemicals or indeed any chemical is necessary or sufficient to cause symptoms, (2) what time period the exposure must span before symptoms will appear, (3) what other conditions must be present to cause MCS, (4) what symptoms will result, (5) how long the symptoms will last, or (6) how severe the reaction will be. MCS detractors, on the other hand, believe that people who claim to have MCS are malingerers or suffer from psychological disorders and that doctors who diagnose the disease are more interested in the generous fees they collect for treating these patients than in accurate diagnosis.

MCS, as diagnosed by its supporters, encompasses almost any and every physical complaint, even contradictory ones, from runny noses to heart palpitations, from increased appetite to decreased appetite to ringing in the ears, from skin rashes to fungal infections, and on and on. The complaints in any given person are numerous and wide ranging. In virtually every case, the somatic complaints are entirely subjective. And despite Herculean efforts to find a mechanism for MCS, the etiology for the MCS disease process still eludes scientists in the field.

The group of practitioners who diagnose and treat MCS call themselves clinical ecologists or environmental physicians. They believe that MCS results when people become so overloaded with chemicals that they systemically are unable to cope with continuing interaction with chemicals. Clinical ecologists posit that at that point the individual's sensitivity "spreads" - that is, the individual ceases to be able to discriminate between the chemical that caused the initial reaction and other chemicals, or even among various concentrations of that same chemical. Thus, even minute amounts of some chemical can cause a severe reaction.(4) This theory, although creative, has not withstood scientific scrutiny.

Part of the problem with MCS rests with its greatest champions - the clinical ecologists. They have fashioned their own professional societies and created their own journals in an attempt to be recognized by the larger medical community. Despite their efforts, however, traditional practitioners of allergy, immunology and toxicology reject the theories and methods of clinical ecology.(5)

Doctors who diagnose MCS generally believe, with great conviction, that they are the last refuge for patients whom orthodox medicine has branded psychosomatics. It is worth noting that many of the most vocal proponents of MCS in the medical profession believe themselves or family members to be "victims" of the scourge of MCS. So, with the mission of validating MCS, clinical ecologists tend to diagnose MCS in anyone with (1) a reported history of exposure to some chemical (which would be everyone) and (2) unexplained symptoms. This results in very high rates of positive diagnoses of MCS, which frequently are based on little more than subjective reporting of symptoms and controversial, unproved "tests."

MCS seems to be particularly popular in a new breed of toxic tort lawsuits. Plaintiffs claim that they suffer from numerous and varied bodily symptoms caused by exposure to some chemical. Represented by one or more of a cadre of lawyers specializing in toxic tort cases, they consult with clinical ecologists who are retained to diagnose the plaintiffs and testify as experts. Since the U.S. Supreme Court's ruling in Daubert v. Merrell Dow Pharmaceuticals Inc.,(6) however, federal courts routinely have excluded their testimony.

DAUBERT AND SCIENTIFIC

TESTIMONY

For a long time, the legal system dealt with controversial expert testimony in a laissez-faire manner. Before Daubert, courts generally operated on the principle that experts who truly presented unscientific theories would be discredited after rigorous cross-examination. However, this approach neglected to recognize the impressive picture a highly credentialed scientist presenting an unscientific theory could paint. Therein lay the crux of the problem facing courts dealing with clinical ecologists before Daubert-many clinical ecologists brought with them very impressive curricula vitae. Before Daubert, these credentials could blind even careful jurors to the hollow nature of the theories clinical ecologists espouse. After Daubert, trial courts are empowered to act as gatekeepers to determine whether expert testimony meets the rigors of the scientific method and thereby qualifies as material worthy of jury consideration.

Since 1993, Daubert and Federal Rule of Evidence 702 govern the introduction of expert testimony in federal courts. Rule 702 provides that if "scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education, may testify thereto in the form of an opinion or otherwise." The Supreme Court in Daubert and the Ninth Circuit on remand of the case(7) have interpreted Rule 702 to require any expert who intends to testify about a "scientific" matter to show that the subject about which he intends to testify is indeed "scientific" and that such testimony will assist the trier of fact to understand the evidence or determine a fact at issue.

1. What Is "Scientific Knowledge"?

   Daubert explained that "scientific knowledge" requires "a grounding in the methods and procedures of science," as well as a basis for the opinion more convincing than mere "subjective belief or unsupported speculation." Thus, the Daubert Court concluded that in order to qualify as scientific knowledge sufficient for admission as expert testimony, the subject of the testimony "must be derived by the scientific method, ... supported by appropriate validation - i.e., `good grounds,' based on what is...