Dr. Brautbar - Causation, Science and the Law: Industrial & Environmental Chemical Toxicity

November 19, 1999

http://www.environmentaldiseases.com/article-toxic1.html

CAUSATION, SCIENCE AND THE LAW: INDUSTRIAL & ENVIRONMENTAL CHEMICAL TOXICITY

By Nachman Brautbar, M.D.*

*This manuscript also summarizes previous publications by Dr. Brautbar

including Science And The Law, Journal of Clean Technology, Environmental

Toxicology & Occupational Medicine, Volume 6, 1997; Science And The Law:

Scientific Evidence, Causation, Admissibility, Reliability. " Daubert "

Decision Revisited, Toxicology & Industrial Health; Establishing Causation

in Forensic Medicine (From Henle To Bradford Hill), Journal of Clean

Technology, Environmental Toxicology & Occupational Medicine, Volume 6,

1997; and Scientific Evidence, Book Chapter.

INTRODUCTION

Occupational and environmental exposure to potentially toxic chemicals has

been reported more frequently in the last five (5) years, most likely as the

result of 1) increased public awareness, 2) improved reporting by

physicians, 3) unlimited access to the information data banks, 4) more

efficient regulatory support, 5) increased recognition by treating and

evaluating physicians.

A physician who evaluates and treats patients with toxic exposure has to

address the issue of causation. This issue of medical causation in toxic

exposures has been the subject of ongoing scientific evolution over the last

forty (40) years. As science evolves so does the understanding of causation

and scientific evidence.

The Methodology For Establishing Cause And Effect:

The evaluating and treating doctor has to establish cause and effect in the

process of providing treatment, diagnosis or the evaluation of a population

of patients for the purposes of consultations for forensic opinions. The

methodology for establishing causation in the medical profession is not new

and has been established and published in various texts, international and

national conferences, and scientific peer-reviewed papers. Despite the fact

that the methodology required to establish causation in toxic exposures has

been well-described, the applicability of that methodology in the forensic

(medical-legal) arena has been a subject of deep division among experts,

attorneys, and the judicial system.

Forensic medicine by its nature is subject to disagreements, especially in

our adversarial judicial system. It is not unusual to find equally

experienced and credentialed experts relying on the same literature and

expressing diametrically opposed scientific opinions. The argument of what

methodology is applicable, especially in toxic exposures disease process, is

so passionate that it is no surprise that the court system in these types of

cases, specifically toxic exposures, has tried to resolve this passionate

argument by applying what was supposed to have meant some " criteria " to

filter out what is sometimes (justifiably and not justifiably) classified as

" junk science' (expert on both sides of the issue, i.e. defense and

plaintiff experts have been labeled as " unreliable " based on some judicial

pretense).

The famous Daubert(1) decision opined in that specific case essentially

stated that the judge is the gatekeeper as far as the experts' proffered

testimony which is admissible based on the following criteria: (1) whether

the theory or technique used by the expert can be, and has been, tested; (2)

whether the theory or technique has been subjected to peer review and

publication; (3) the known or potential rate of error of the method used;

and (4) the degree of the method's or conclusion's acceptance within the

relevant scientific community.

Since the famous Daubert decision much confusion, and at times

misunderstanding of causation, scientific evidence, and expert testimony

reliability have arisen, nicely summarized in the statement by Professor

Capra in his paper: " This schizophrenic aspect of Daubert... " .(2) From

review of what always used to be the scientific basis for causation and

careful review of some of the recent cases " utilizing " the Daubert, it is no

surprise that many courts have been divided in the application of those

criteria when it comes to admissibility of expert testimony.

This deep division and what is described by some scholars as the

" schizophrenic " aspect of Daubert has been recently experienced by me as a

lecturer for State Court Judges from across the United States at the

National Judicial College in Reno (November of 1998) in a session

specifically addressing science in the courtroom. After I completed my

presentation, which essentially addressed the methodology to be utilized and

which is used by medical experts in order to establish causation, a very

lively, intellectual, practical and productive discussion took place, the

Honorable Judge Andre M. and Attorney Roisman (who is well

known in the environmental law circles) moderated the discussion. One of the

judges from the State of Texas posed a question as follows, " I am a State

Court Judge in a farming community where a relatively new chemical has been

used for the last 2 years. No peer-reviewed literature is yet available

since this is a new chemical, the material safety data sheets lack long-term

information due to the fact that this is a new chemical, and several cases

have come up where credible patients presented with history of exposure and

evidence of injury. " The judge further continued, " The doctor who treated

those patients opined that the injuries are the result of exposure to this

chemical (which in animals can cause a similar type of injuries), however

defendants motioned the court to exclude the doctor's testimony based on the

decision,(3) (which essentially applies Daubert criteria to a state

court law in Texas). " The judge further asked, " The patient's are credible,

the doctor is credible, there is a chain of events and temporal

relationship, and treatment was required after the exposure to this

chemical, but on the other hand I have these criteria established in the

Daubert decision and applied to the state court in Texas under the

decision. " The scenario described by the Honorable Judge is not a unique one

and in actuality is a very common one, one that physicians, insurance

companies, attorneys, and courts throughout the country struggle with on a

daily basis. If one has to take the rigid inflexible interpretation of the

Daubert decision (which initially was supposed to be much more liberal and

not inflexible) then, regardless whether the doctor ruled out other

diseases, regardless whether the doctor reviewed medical records and found

no evidence for other causes, other than the exposure, no matter if the

material safety data sheets described this chemical as capable of causing

injuries to the lungs and upper airways in experimental animals, the mere

fact that this is a new chemical and there is no " peer-reviewed scientific

literature published " addressing that specific chemical to these specific

injuries there is no redress for the injured patients. On the other hand, if

one adopts the methodology which is used by medical doctors, specifically,

history, differential diagnosis, diagnostic studies, ruling out other

causes, review of medical records, and review of the scientific literature,

reliance on this methodology has served the medical profession for many

years clearly establishes causation in this specific case given this

theoretical scenario. To lead us in this quandary, I have chosen to quote

parts of the Honorable Justice Dennis' dissenting opinion and the appellates

decision in Bob T. v. .(4) Judge Dennis opined that the

majority opinion (of the appellate court in this case) creates a " schism "

between this court (the 5th Circuit Court) and other circuits, and state

court of last resort, and disregards the teachings of federal evidence law

scholars. The 2nd, 3rd, and 4th Circuits had held that a clinical physician

may, consistently with Daubert, express an opinion, based on clinical

medical methodology generally accepted within that discipline, that the

particular toxic substance caused the patient's disease or death without

hard, scientific collaboration under an inflexible application of the

Daubert factors. Judge Dennis relied, among others, on the 2nd circuit

decision in the McCulloch case(5) where the court rejected defendant's

argument for exclusion of the clinical physician opinion as scientifically

unfounded that glue fumes caused the plaintiff's respiratory symptoms and

throat polyps. In that case, the evaluating doctor based the opinion upon

his use of clinical medical methodology without any " hard science " or strict

Daubert factor related basis. The defendant in that case argued that the

doctor could not point to a single piece of medical literature that said

that glue fumes caused throat polyps. The Court in that case, however,

stated that the doctor based his opinion on a range of factors which include

1) his current treatment of the patient, 2) medical history, 3) pathological

studies, 4) review of Material Safety Data Sheets, 5) the doctor's training

and experience, 6) the use of scientific analysis known as differential

etiology (which requires listing possible causes and then eliminating all

causes except one) and 7) reference to various scientific and medical

treaties. While there is no doubt in my mind that some conservative courts

would hold the opinion that the doctors methodology in the McCullough case

was " junk science " because there was " no peer review " of literature

addressing that specific glue fumes, the court clearly stated that the

doctor relied on the methodology used by medical doctors, accepted

methodology used in the same discipline, mainly medicine. Judge Dennis also

relied on the Benedi court (6) where the court clearly stated, " We will not

declare the clinical medicine methodologies invalid and unreliable in light

of the medical community's daily use of the same methodologies in diagnosing

patients. " I believe that Judge Dennis' opinion summarizes many traditional

legal and medical scholars opinions as far as the methodology to be relied

upon by medical experts. Judge Dennis' following statement sheds much light

on what has been made so confusing and complicated by extremely

conservative, and in my opinion, unreasonable parties. Specifically, Judge

Dennis' opinion that, " the embank majority, in my opinion, makes several

errors of law, the most serious of which is its holding that the clinical

medical expert whose opinion is based on the sound cooperation of the

principles of methodology of his or her discipline, cannot reliably testify

as to the causal relationship between an individual's exposure to a chemical

compound and his or her subsequent onset of symptoms and disease. As a

result of this error of law in others, the embank opinions subverts the

liberal thrust of the federal rules of evidence and the principles

enunciated in Daubert by locking the gate on causation evidence derived

through the principles and methodology of clinical medicine. " Judge Dennis'

opinion indeed represents (at least in my opinion) a rationale assessment of

the methodology used to establish causation, and as such, admissibility.

Indeed, as we will see later in this manuscript, the U.S. Supreme Court

essentially supports this approach in its recent Kumho Tire decision.

The most recent Supreme Court decision in Kumho Tire Co., LTD, et al, v

Carmichael, et al,(7) dealt with these specific issues and provided

reasonable and ethical interpretation of the Daubert criteria. Essentially,

what the Supreme Court opined is the following: While the Daubert criteria

are intended to serve as a tool to examine the reliable basis of an expert's

prior to admitting the expert's testimony (applied to all experts), the

Daubert factors are not definitive nor inclusive, and the Daubert factors

may or may not be pertinent depending on the specific case in front of the

court. The court specifically stated, " We agree with the Solicitor General

that the factors identified in Daubert may or may not be pertinent in

assessing reliability, depending on the nature of the issue, the experts

particular expertise, and the subject of his testimony. " The court further

stated that " Daubert itself is not to the contrary. It made clear that its

list of factors was meant to be helpful, not definitive. " The court further

stated, " It might not be surprising in a particular case, for example, that

the claim made by a scientific witness has never been of peer review, for

the particular application at issue may never previously have interested any

scientist. Nor, on the other hand, does the presence of Daubert's general

acceptance factor help show that an expert's testimony is reliable when the

discipline itself lacks reliability, as, per example, do theories grounded

in any so-called generally accepted principles of astrology or necromancy. "

The court further stated, " The objective of that requirement (the importance

of Daubert gatekeeping requirement) is to insure the reliability and

relevance of expert testimony. It is to make certain that an expert whether

basing testimony upon professional studies or personal experience, employs

in the courtroom the same level of intellectual rigor that characterizes the

practice of an expert in the relevant field. " The court further opined,

" Rather, we conclude that the trial judge must have considerable leeway in

deciding in a particular case how to go about determining whether particular

expert testimony is reliable. That is to say, a trial court should consider

the specific factors identified in Daubert where they are reasonable

measures of the reliability of expert testimony. " Essentially, the Kumho

decision clarifies the Daubert decision, and clearly states that it is the

judge's discretion to decide when and if to use the Daubert criteria and

that the criteria are construed in a flexible manner. (While conservative

parties were rushing into extremes of interpretation, the wording of the

Kumho Tire court is clear: The judge has the discretion to decide when to

apply Daubert, when Daubert is not relevant, and when to admit an expert's

testimony based on professional experience and methodology used in that

specialty.)

If we go back to my experience at the National Judicial College in Reno, and

the question that the Judge from Texas posed to me, in my opinion, and in

light of the Kumho decision, it is within the judge's discretion to decide

whether for this particular chemical which is new, there is no peer-reviewed

literature, there is no known range of error, the accepted methodology of

clinicians is the litmus of admissibility of the doctor's methodolgy.

Medical experts in the field of toxic exposure must adhere to the

methodology utilized in the field of medicine, specifically, 1) HISTORY OF

THE EVENT OR EVENTS, PAST MEDICAL HISTORY OF THE PATIENT, INCLUDING FAMILY

HISTORY, SOCIAL HISTORY AND OTHER EXPOSURES; 2) REVIEW OF MEDICAL RECORDS;

3) DIAGNOSTIC STUDIES APPLICABLE IN THE CASE; 4) DIFFERENTIAL DIAGNOSIS,

RULING OUT OTHER CAUSES; 5) RELIANCE ON EITHER GOVERNMENTAL PUBLICATIONS,

MATERIAL SAFETY DATA SHEETS; 6) CASE REPORTS, EPIDEMIOLOGICAL STUDIES IF

AVAILABLE, AND DATA FROM EXPERIMENTAL ANIMALS.

The Kumho Tire court decision and its logic has been most recently applied

in the case of Hannelore v Quality Stores, Inc, et al.(8) In that

opinion the 4th Circuit U.S. Court of Appeals ruled on 06/14/99 that the

opinions of the experts offered in a chemical exposure case were based on a

reliable differential diagnosis and a strong temporal relationship between

exposure and the onset of symptoms and therefore should have been admitted.

Initially the issue in the case was that the District Court entered summary

judgment for Quality (defendants), holding that the experts' opinions were

not reliable because there was no evidence of quantifying the levels of

exposure and finding that in the absence of additional testimony on

causation the evidence was not sufficient to raise a genuine issue of fact.

The U.S. Court of Appeals for the 4th Circuit clearly disagreed with that

approach. In their opinion they stated that in a previous case on 05/20/99,

Westbury v Gislaved Gummiab,(9) they upheld that an expert's opinion based

on differential diagnosis and strong temporal relationship between exposure

and the onset or worsening of symptoms is sufficiently trustworthy to

satisfy the liability prong of Rule 702. They have essentially followed the

line of thinking and reasoning as did the honorable Judge Dennis and as did

the other court, specifically that a medical doctor relying on differential

diagnosis, temporal relationship, and general knowledge on the generic

effects of a chemical, is reliable and admissible. In the Westbury case, the

appellate court clearly stated that, " The temporal relationship between

Westbury's exposure and the onset and worsening of his sinus disease

provided support for Dr. Eisenhower's opinion that talc was the source of

the problem. "

In my opinion, the Supreme Court decision in the Kumho cases is a reasonable

" relaxation " of the Daubert decision (which in my opinion has been " used " by

defendants, and at times misunderstood by plaintiffs), and provides a

reasonable middle ground for the judge to be the fair gatekeeper of expert's

testimony with the understanding that the judge should use flexible

criteria.

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