Court: Court of Appeals for the Eighth Circuit; August 2, 1994; Federal Appellate Court
Kristofer and Katrina Sorensen, who have mental retardation, claim their condition was caused by their parents' consumption of Shaklee alfalfa health food tablets, which were allegedly contaminated with chemical residues from ethylene oxide (EtO) used in sterilization. Union Carbide produced the EtO. The plaintiffs, represented by their mother Laura E. Dunbar, allege that the chemical treatment of the alfalfa tablets led to their birth defects. The district court, after evaluating conflicting medical and scientific evidence, granted summary judgment for the defendants due to insufficient proof of causation. The Sorensens appeal, questioning whether they provided admissible evidence to establish a jury question on causation, referencing the Supreme Court’s Daubert decision on expert testimony standards. The court affirms the district court's decision. Background details include that in 1974, Shaklee isolated contaminated tablets and sent them for sterilization with EtO, while testing later revealed traces of ethylene chlorohydrin (ETCH) but no EtO residue. Shaklee's records do not clarify the fate of the fumigated tablets, and it asserts that any distributed tablets would have been consumed before the plaintiffs’ conception. Recommendations from the WARF Institute highlighted that while the acute toxicity of ETCH was not concerning, there could be long-term effects on future generations due to its mutagenic and teratogenic properties.
The Code of Federal Regulations specifies no tolerances for Ethylene Oxide (EtO) in food products, except for walnut meats, spices, and copra, which the tested ingredients do not fall under. WARF's expert recommends a recall of all products containing fumigated ingredients with EtO due to toxicological concerns, leading to a halt in EtO fumigation practices. In a September 27, 1977 memorandum, Shaklee, after consulting legal counsel, disputed WARF’s classification of alfalfa under the regulations but ultimately decided to destroy its supply of EtO-treated alfalfa tablets and powder. From August 1977 to February 1978, Shaklee ceased distribution of these tablets and initiated development of a non-chemical heat sterilization method. An October 6, 1977 memorandum documented employee interviews revealing that some Shaklee officials, including Vice President George Lieberman, showed indifference toward checking for EtO residues.
Nord Sorensen and Laura Dunbar began using Shaklee products in late 1975 or early 1976, influenced by Laura's mother, Janet. They procured additional products from local distributors and Janet's remaining supply until June 1978. During the late 1977 to June 1978 period, Laura averaged two to four alfalfa tablets daily, while Nord consumed six to eight. Laura also smoked and drank moderately during this time. Afterward, her intake reduced to one or two tablets daily before her subsequent pregnancy. Both of their children, Kristofer and Katrina, were born with severe mental retardation and similar physical traits, while their third child had no disabilities. The couple later divorced, and Laura had a healthy child with her second husband. Family medical histories revealed some mild disabilities in Laura's relatives but none in Nord's family.
Plaintiffs Kristofer and Katrina Sorensen, represented by their parents Nord Sorensen and Laura Dunbar, initially filed a lawsuit in Iowa state court against multiple defendants, including Shaklee and Union Carbide. Before the state court resolved a motion for summary judgment by Shaklee, the plaintiffs voluntarily dismissed their case and refiled in federal district court based on diversity of citizenship. Their federal claims included allegations of misrepresentation, negligence, strict liability, breach of warranty, fraud, and res ipsa loquitur against Shaklee, and similar claims against Union Carbide. Most defendants settled or were dismissed, leaving only Shaklee and Union Carbide. The district court granted summary judgment in favor of the defendants.
In reviewing the evidence, particularly the testimonies of the plaintiffs' expert witnesses, the district court noted a lack of scientific literature linking exposure to ethylene oxide (EtO) or ethylene chlorohydrin (ECH) with mental retardation. No expert had published peer-reviewed findings to support claims that EtO or ECH could cause birth defects, nor was there evidence of a statistically significant association between EtO-sterilized alfalfa tablets and mental retardation. Additionally, the experts were unable to identify the number or amount of mutagenic agents to which the plaintiffs' parents were exposed. Each expert assumed that only EtO and/or ECH were involved, failing to account for other potential mutagenic or teratogenic exposures.
Dr. Henry T. Lynch, a prominent expert in medical genetics, provided the most substantial support for the plaintiffs' case. He asserted, with scientific certainty, that the Sorensen children’s conditions were linked to their parents' consumption of Shaklee’s alfalfa tablets treated with EtO. Dr. Lynch proposed two potential mechanisms for the children's mental retardation: a germ line mutation involving gonadal mosaicism or a multifactorial induced effect via transplacental exposure to EtO/ECH from the mother.
Dr. Lynch asserted that understanding the mechanism of a disorder was not necessary to form an opinion about its etiology with scientific certainty. He indicated that even minimal exposure could lead to teratogenic or mutagenic effects, linking EtO and/or ETCH to potential mutations in the germ line cells of Nord Sorensen or Laura Dunbar, or teratogenic impacts from Laura's exposure during pregnancy. However, during subsequent depositions, he expressed uncertainty, acknowledging the lack of research on ingested EtO and ETCH and stating that while these substances could possibly have contributed to the children's mental retardation, he could not definitively identify them as the cause, especially given other potential exposures.
Epidemiologist Matthew J. Severin, Jr. opined that the children's condition was not linked to infections but suggested a point mutation at the germinal cell layer. In his March 1989 affidavit, he claimed with scientific certainty that the mental retardation resulted from exposure to alfalfa tablets treated with EtO. Yet, by June 1992, he revised his position to indicate that EtO was merely a possible cause due to insufficient evidence to establish a definitive relationship with the children’s condition. Dr. Severin dismissed the notion that their symptoms were nonspecific based on their similar presentations. Geneticist William Kimberling also supported the plaintiffs, stating that given exposure, it was reasonable to assume that ethylene oxide caused mutations leading to the children's issues.
Dr. Kimberling could not affirm with a reasonable degree of medical certainty that ethylene oxide (EtO) caused the mental retardation in the case. He noted that if Shaklee’s alfalfa tablets contained no residual EtO, they could not be implicated as the cause, and he had no evidence to support retention of EtO in those tablets. Dr. Carol Remmer Angle, a pediatrician and toxicology expert, based her assessment on an exposure rate of 3000 ppm per tablet from a 1974 batch, concluding that Laura ingested 0.24 mg of ethylene chlorohydrin (ECH) per kilo per day. However, she later acknowledged a lack of evidence for EtO in the tablets and was unaware of any documented human oral toxicity or teratogenic effects from EtO-sterilized foods. While she stated it was scientifically plausible that EtO could be implicated in the children's mental retardation, she did not assert a definitive cause and emphasized the need for experimental evidence and a replicable mechanism in toxicological conclusions.
Dr. Angle referenced studies indicating EtO's carcinogenicity in animals and potential adverse reproductive effects, but she did not evaluate the methodological rigor of two Russian studies she reviewed, which suggested mutagenic effects in rats at non-lethal doses. The estimated ECH intake by the parents was found to exceed the human mutagenic dose predicted from animal studies. In contrast, experts for the defendants, including those specialized in toxicology and psychiatry, concluded with scientific certainty that the consumption of EtO or ECH from the alfalfa tablets could not have caused the mental retardation. Furthermore, Dr. William Wadell testified that Laura Dunbar's reported consumption of cigarettes and alcohol during pregnancy would have resulted in greater exposure to EtO than from the tablets, even at the highest estimated levels.
The district court determined that the plaintiffs did not establish a causal link between Shaklee’s ETO-treated alfalfa tablets and the plaintiffs’ mental retardation, as the testimony of the three experts merely suggested a "possible cause," which was insufficient for proving proximate causation. Dr. Lynch, the most relevant expert for the plaintiffs, acknowledged the limitations of his small sample size and relied on cumulative evidence without conducting independent testing. His conclusions lacked peer-reviewed support or general acceptance, casting doubt on the validity of his scientific methodology.
The admissibility of scientific evidence in this case is governed by the standards set forth in Daubert v. Merrell Dow Pharmaceuticals, Inc., which interprets Federal Rules of Evidence 702 and 703. The precedent involved a case where plaintiffs claimed birth defects in children resulted from their mother's use of Bendectin, but the defendant provided extensive epidemiological evidence showing no link. The plaintiffs failed to contest the defendant’s evidence effectively and presented their own experts, who based their conclusions on studies that had not undergone peer review and were generated for litigation purposes. The Ninth Circuit upheld the district court's summary judgment in favor of the defendant, applying the Frye Rule's general acceptance test and finding the plaintiffs' reanalysis of studies insufficient for establishing causation.
The Supreme Court granted certiorari to establish the standard for admitting expert testimony, unanimously rejecting the Frye Rule, which required "general acceptance" for such admission. The Court emphasized that the Federal Rules of Evidence do not incorporate the Frye standard and instead require trial judges to ensure that scientific testimony is both relevant and reliable. The decision, particularly Justice Blackmun's opinion, outlined key criteria for admissibility under Rule 702. It highlighted that expert testimony must assist the trier of fact in understanding evidence or determining relevant facts. The concept of "fit" was introduced, indicating that expert testimony must be closely tied to the case facts to be helpful, and that scientific validity can differ based on context. The Court noted that trial judges must preliminarily assess whether the expert's methodology is valid and applicable to the facts at hand. In the present case, the plaintiffs failed to demonstrate that the expert testimony regarding Shaklee alfalfa tablets and their potential EtO residue met these admissibility requirements, lacking a reliable basis for relevance and scientific validity. The inquiry under Rule 702 focuses on the principles and methodologies rather than the conclusions drawn from them.
Daubert establishes factors for assessing whether expert testimony pertains to relevant scientific knowledge, including:
1. **Testability of Theory**: Dr. Lynch's potential causal mechanisms, including germ line mutation and multi-factorial phenomena, as well as Dr. Severin's point mutation theory related to EtO residue ingestion, have not been empirically studied. Plaintiffs’ experts acknowledge the ethical issues of human studies but do not provide animal study evidence linking EtO-sterilized food products to mental retardation.
2. **Peer Review and Publication**: The plaintiffs’ theories have not undergone peer review or publication, which weakens their scientific credibility.
3. **Known Rate of Error**: This factor is irrelevant as the testimony concerns broad theories rather than specific techniques.
4. **General Acceptance**: There is no evidence supporting the acceptance of the plaintiffs’ theories or methodologies within the scientific community. The reasoning of the plaintiffs’ experts lacks scientific rigor, relying on the flawed logic that because birth defects occurred and parents used Shaklee’s alfalfa tablets containing EtO residue, the latter must have caused the defects. This approach reverses proper scientific reasoning, starting from a conclusion rather than established facts.
The district court highlighted several unsupported assumptions made by Dr. Lynch, such as the absence of other potential mutagenic or teratogenic exposures experienced by the plaintiffs' parents. This raises concerns about the reliability of Lynch’s conclusions.
The Seventh Circuit's decision in O’Conner v. Commonwealth Edison Co. serves as a parallel example where an expert's unsupported opinion on the cause of cataracts was deemed inadmissible due to lack of scientific methodology, underscoring the importance of empirical support for expert testimony.
In Porter v. Whitehall Laboratories, Inc., 9 F.3d 607 (7th Cir. 1993), a product liability case emerged from the plaintiff's kidney failure allegedly linked to ibuprofen ingestion. While awaiting surgery for a work-related toe injury, the plaintiff consumed Motrin (prescription ibuprofen) and over-the-counter ibuprofen provided by his internist’s nurse practitioner. Following this, he developed kidney failure necessitating a transplant. Two expert theories were proposed: 1) rapidly progressive glomerulonephritis (RPGN) due to anti-glomerular basement membrane glomerulonephritis (anti-GBM) and 2) unspecified RPGN, possibly induced by anti-GBM or membranoproliferative glomerulonephritis (MPGN). The Seventh Circuit upheld the district court's summary judgment favoring the pharmaceutical companies, ruling that the expert testimony lacked scientific grounding and methodology, thus being inadmissible. The court emphasized that expert testimony must be relevant and reliable and assist in understanding the case's factual issues as per Rule 702. The court noted that the plaintiffs' experts failed to demonstrate scientific validity and relevance to the case, and reiterated that the "fit" of expert testimony to the facts is critical for its admissibility.
Expert testimony must demonstrate (1) scientific knowledge and (2) relevance to assist the trier of fact in understanding or determining an issue. A preliminary assessment is required to evaluate the scientific validity of the reasoning or methodology behind the testimony and its applicability to the case facts. In this instance, the plaintiffs' proposed expert testimony does not meet admissibility standards due to a lack of evidence showing that the Shaklee alfalfa tablets taken by their parents contained any ethylene oxide (EtO) residue.
The court emphasizes that the analysis under Rule 702 is flexible and centers on the scientific validity and evidentiary relevance of the underlying principles, rather than the conclusions drawn from them. Factors outlined in Daubert include:
1. Testability of the theory, which has not been demonstrated by the plaintiffs’ experts regarding their proposed causal mechanisms.
2. Peer review and publication status, which the plaintiffs’ theories have not undergone.
3. Known error rates, which are irrelevant here as the testimony pertains to theories rather than specific techniques.
4. General acceptance within the scientific community, which has not been established for the theories presented.
The plaintiffs' reasoning, which suggests that birth defects in children can be directly linked to the ingestion of EtO residue from alfalfa tablets, is criticized for lacking a scientific basis. The experts' approach improperly infers causation from an outcome rather than established facts, making their reasoning scientifically unsound, especially given multiple potential causes for the observed effects.
Lynch's assumptions regarding the plaintiffs' exposure to substances that could cause mutagenic or teratogenic effects are unsupported by the record, including claims about the absence of other potential causes, such as cigarette smoking, and the levels of ETO or ECH in the tablets ingested. This lack of support indicates a high potential for error in Lynch's analysis. The district court cited the case O’Conner v. Commonwealth Edison Co., where a medical expert's opinion linking cataracts to radiation exposure was rejected due to a lack of scientific methodology and personal study, rendering the testimony inadmissible. Similarly, in Porter v. Whitehall Laboratories, Inc., expert testimony regarding the cause of a plaintiff's kidney failure was excluded for failing to adhere to scientific principles, leading to a summary judgment for the defendants. The district court noted that the plaintiffs’ experts did not address essential scientific validity considerations, and the testimony lacked a reliable methodological foundation. Under Daubert standards, expert testimony must be relevant and reliable, but not necessarily proven with certainty. The excerpt also references Cantrell v. GAF Corporation, which involved expert testimony on injuries caused by asbestos exposure, illustrating complex admissibility issues in expert evidence.
An expert's opinion, derived from an examination of plaintiffs and prior diagnoses of laryngeal cancer among 150 workers at a plant, suggests a synergistic effect between cigarette smoking and asbestos exposure in Cantrell's case. The Sixth Circuit upheld the admission of this expert testimony, stating that Rules 702 and 703, along with Daubert, allow experts to present confirmatory data from personal clinical experience regarding disease origins and exposure consequences. Judge Wellford concurred reluctantly, viewing the expert's testimony as improperly admitted. The expert noted an unusual incidence of laryngeal cancer at the Lockland facility, likening the situation to a witness testifying about a dangerous railroad crossing based on a few prior accidents.
Additionally, the Tenth Circuit supported the admission of an accidentologist's testimony regarding vehicle and train positions during collisions for illustrative purposes, emphasizing the need for trial judges to rigorously evaluate animation evidence for foundation, relevance, and potential prejudice. The court noted that while scientific principles could explain crash movements, opinions on specific outcomes might exceed scientific knowledge.
The application of Daubert remains evolving in relation to expert testimony admissibility. District judges may also seek expert assistance through Rule 706 to aid in their gatekeeping roles. Ultimately, the evidence presented by the plaintiffs was deemed insufficient to establish causation, particularly regarding the consumption of alfalfa tablets and the presence of EtO residue, leading to the affirmation of the summary judgment of dismissal by the district judge.
The parties are in disagreement over the quantity of contaminated tablets, with Shaklee asserting a figure of 64023 million compared to the plaintiffs' reference of 62 million from an internal memorandum dated three years post-sterilization. For the appeal, the precise number of contaminated tablets is deemed non-essential. Ethylene oxide (EtO) is regulated federally as a fumigant for controlling microorganisms and pests in certain food products, with specific conditions outlined, including a maximum residue limit of 50 parts per million in whole spices. Despite EtO being classified as hazardous, the appeal’s resolution does not require determining if the alfalfa tablets qualify as a "ground spice."
Confusion arises from the abbreviation of ethylene chlorohydrin as ECH, which is incorrectly aligned with epichlorohydrin, a different compound. Both substances are recognized as toxic. The plaintiffs' federal complaint differs from the state case, omitting Nord Sorensen as a parent and next friend, and the district court's reference to ECH remains consistent.
The document explains the definitions of "mutagen" and "teratogen," highlighting that epidemiology is a discipline that uses statistical methods to assess disease incidence in populations exposed to specific chemicals. While epidemiological studies aim to identify disease causes, they may only demonstrate associations between exposure and disease, lacking definitive proof of causation; they can only indicate a probability that exposure contributed to a particular case of disease.
Steve Gold's analysis in "Causation in Toxic Torts" discusses the complexities of establishing causation in toxic tort cases, particularly regarding Bendectin and its alleged link to birth defects. Over two thousand lawsuits were filed against Merrell Dow, predominantly resulting in no judgments for plaintiffs. Key legal standards governing expert testimony are outlined, including Federal Rules of Evidence 702 and 703, which permit expert opinions based on specialized knowledge and data, even if such data is not admissible as evidence. The excerpt also contrasts methodologies for testing teratogenicity, noting that in vitro studies assess the effects of substances on isolated biological samples, while in vivo studies evaluate the impact of drug ingestion during pregnancy on animal fetuses. However, differences in dose-response between humans and animals complicate extrapolating findings from animal studies to humans. The structure-activity relationship hypothesis is critiqued for its inadequacy, as even minor molecular variations can lead to significantly different effects. The text references the Frye standard, which requires scientific evidence to gain general acceptance in its field, and cites several cases that have shaped the legal landscape surrounding the admissibility of scientific evidence in court.
The excerpt lists various legal cases addressing the admissibility of scientific and expert evidence, highlighting the application of the Daubert standard across multiple jurisdictions. Key cases include:
1. **Pioneer Hi-Bred Int’l v. Holden Foundation Seeds, Inc.** - Discusses electrophoresis and chromatography.
2. **United States v. Johnson** - Involves drug trafficking.
3. **United States v. Jones** - Focuses on voice identification techniques.
4. **United States v. Quinn** - Utilizes photogrammetry for height identification.
5. **United States v. Muldrow** - Addresses identity and quantity of cocaine involved.
6. **United States v. Lee** - Concerns machine detection of trace cocaine.
7. **United States v. Sepulveda** - Explores the economics of cocaine trade.
8. **United States v. Locascio** - Examines organized crime operations.
9. **United States v. Daccarett** - Discusses money laundering methods.
10. **Petruzzi's IGA Supermarkets, Inc. v. Darling-Delaware Co.** - Focuses on economic testimony.
11. **United States v. Bynum** - Involves chromatographic analysis of cocaine.
12. **United States v. Bonds** - Addresses DNA evidence.
13. **Elkins v. Richardson-Merrell, Inc.** - Concerns birth defects from Bendectin.
14. **Cantrell v. GAF Corp.** - Discusses asbestosis causation.
15. **Porter v. Whitehall Lab. Inc.** - Involves ibuprofen-related kidney failure.
16. **Joy v. Bell Helicopter Textron, Inc.** - Addresses future earning capacity.
17. **State v. Foret** - Discusses Child Sexual Abuse Accommodation Syndrome (CSAAS).
18. **State v. Cressey** - Involves sexual abuse cases.
19. **State v. Alberico** - Concerns Post-Traumatic Stress Disorder (PTSD).
20. **Rincon v. United States** - Suggests broad application of Daubert regarding eyewitness identification reliability.
The excerpt emphasizes that Daubert's rationale applies to both scientific evidence and expert opinions, with the Supreme Court advocating for its broad application in assessing the admissibility of expert testimony. Rule 104(a) is cited regarding general questions of admissibility.
Preliminary questions regarding a person's qualifications as a witness, the existence of a privilege, or the admissibility of evidence are to be decided by the court, which is not strictly bound by traditional evidentiary rules except for those related to privileges. Recent amendments to federal discovery rules require thorough early evaluations of evidentiary issues. Plaintiffs' research indicates that Ethylene Oxide (EtO) is carcinogenic to rats and mice, poses potential cancer risks to humans, and produces harmful reproductive and genetic effects across various animal studies. The validity of two Russian studies cited by the plaintiffs regarding EtO's mutagenic effects on mammals has been questioned. While peer review is not definitive regarding the scientific validity of methods or theories, it is still recognized as a significant process. Furthermore, there is no recorded judgment entry in this case, and the order granting summary judgment is not the final order. Nonetheless, the parties have acted as if a summary judgment had been issued, and the appeal will not be dismissed due to this procedural technicality, although appellants should be cautious about the lack of a final judgment in summary judgment cases.
