National Bank of Commerce v. Assoc. Milk Producers, 98-2851

• Decision Date: 17 June 1999
• Docket Number: No. 98-2851,98-2851
• Parties: (8th Cir. 1999) National Bank of Commerce (of El Dorado, Arkansas), Conservator of the Estate (only) of John McDougal; John McDougal, Individually; Appellants v. Associated Milk Producers, Inc.; Appellee. Submitted:
• Court: U.S. Court of Appeals — Eighth Circuit

Page 858

191 F.3d 858 (8th Cir. 1999)

National Bank of Commerce (of El Dorado, Arkansas), Conservator of the Estate (only) of John McDougal; John McDougal, Individually; Appellants v. Associated Milk Producers, Inc.; Appellee.

No. 98-2851

United States Court of Appeals FOR THE EIGHTH CIRCUIT

Submitted: June 17, 1999

Filed: September 10, 1999

Rehearing and Rehearing En Banc Denied Oct. 19, 1999.

Appeal from the United States; District Court for the Eastern District of Arkansas.

Before BOWMAN and HEANEY, Circuit Judges, and LONGSTAFF, District Judge.¹

HEANEY, Circuit Judge.

The sole question before us on appeal is whether the district court abused its discretion in refusing to admit into evidence plaintiff John McDougal's proffered expert testimony that he developed laryngeal cancer as a result of exposure to aerosolized milk containing aflatoxin M-1 (AFM) in a cheese plant at which he was employed for a period of fifteen months. Although the question is not free from doubt, we find no abuse of discretion.

I.

Defendant, Associated Milk Producers, Inc. (AMPI), is a cooperative of dairy farmers operating in fourteen states in the Midwest and Southwest. AMPI uses tanker trucks to pick up milk from its dairy farm members and deliver it to Grade A milk bottling companies and cheese-making companies, including Hills Valley Foods in Batesville, Arkansas.

John McDougal was employed at Hills Valley Foods from July 26, 1990 to October 31, 1991. During that time period, AMPI delivered many truckloads of milk to Hills Valley Foods, five of which contained AFM in excess of the .5 parts per billion level permitted by the Food and Drug Administration.² AFM is a potent. hepotocarcinogen (Tr. at 160-61). It is undisputed that McDougal was exposed to aerosolized milk particles from these truckloads of milk containing AFM. On February 27, 1995, McDougal was diagnosed as having laryngeal cancer and had surgery for the removal of the cancer. The surgery left him unable to speak or breathe without the use a tracheal tube.

In June 1995, McDougal learned that four AMPI employees pled guilty in federal court for the distribution of and conspiracy to distribute contaminated milk in interstate commerce. After learning of the guilty pleas, McDougal commenced an action against AMPI in the United States District Court for the Eastern District of Arkansas, alleging that his laryngeal cancer had been caused by the aerosolized milk particles containing AFM. In the course of the proceeding, McDougal's counsel obtained several expert witnesses in order to establish that McDougal's laryngeal cancer was caused by his exposure to the AFM while employed at Hills Valley Foods.AMPI filed a motion to exclude McDougal's expert causation testimony, asserting that the testimony failed to meet the admissibility requirements set forth in Daubert v. Merrell Dow Pharm., Inc., 509 U.S. 579 (1993). After a six-day hearing with submission of briefs and oral argument, the district court, in a seventy-seven page opinion, excluded the testimony of McDougal's experts and granted AMPI's motion for summary judgment. See National Bank of Commerce v. Associated Milk Producers, Inc., 22 F. Supp.2d 942 (E.D. Ark. 1998). It did so on the following grounds:

[T]he Court finds that there is no scientific literature drawing a direct connection between the inhalation of vapors containing AFM (or any other exposure to AFM) and the occurrence of laryngeal cancer in humans. Neither party has proffered any study, experiment, or other publication in which any exposure to AFM was found to cause laryngeal cancer in humans. Moreover, there is no scientific evidence showing that the much more potent aflatoxin B-1 causes larynx cancer in humans. Where there is no direct scientific knowledge that a particular substance causes a particular form of cancer in humans, experts must turn to epidemiological studies, in vitro studies, animal studies, and other indirect methods in an attempt to make the connection. Here, there are no such studies in which AFM or AFB have been shown to cause cancer of the larynx.

Id. at 951-52 (emphasis in original).

In so holding, the court rejected McDougal's theory that "there is no threshold for genotoxins, in that any one molecule of such a carcinogenic mutational agent can produce alterations in genetic material leading to cancer." Id. at 958. The district court began by reviewing the Reference Manual on Scientific Evidence (Reference Manual) and other literature on the theory and noted that the "no threshold" model ³ has been adopted by the Occupational Safety and Health Administration (OSHA) in its regulation of workplace carcinogens and the fact that these regulations have been upheld in federal court. Id. at 959, n.8 (quoting Public Citizen Health Research Group v. Tyson, 796 F.2d 1479, 1498 (D.C. Cir. 1986), clarified sub nom., Public Citizen Health Research Group v. Brock, 823 F.2d 626 (D.C. Cir. 1987)). Citing to the Reference Manual, the court stated:

[I]t is unlikely that any one molecule of a potentially cancer-causing agent will reach that one particular spot in a specific cell and result in the change that then eludes the body's defenses and leads to a clinical case of cancer. However, the risk is not zero. As developed during the testimony, and explored in the Sutera case, regulatory agencies employ a different perspective in setting "action levels" than do the courts in imposing tort liability. Establishing that the risk of causation "is not zero" falls woefully short of the degree of proof required by Daubert and its progeny.

Id. at 961 (quotation omitted).

The court concluded that "the 'no-threshold' or 'one-shot' theory has respectable scientific support [b]ut . . . does not provide a scientific basis for a jury to find that it was more likely than not that John McDougal's cancer was caused by AMPI's exposing him to milk contaminated with aflatoxin M-1." Id.

The district court similarly rejected the contention that McDougal's "differential diagnoses" report significantly buttressed the causation analysis. Id. at 963. In this report McDougal pointed out that it is extremely rare for a person of his age to develop laryngeal cancer, that 75 to 90 percent of all such cancers are caused by smoking tobacco or drinking alcohol, and that he neither smokes nor drinks. See id. According to McDougal, these facts make it unlikely that his cancer was caused by factors other than exposure to AFM. See id.

The district court was not convinced that the plaintiffs had successfully ruled out other possible alternative causes such as second-hand smoke from McDougal's parents and sibling or the possibility that he was exposed through his diet to other carcinogens. Id. at 963-66. Moreover, even if they had been able to rule out other causes, the court observed that plaintiffs had not 'ruled in' that the toxin to which McDougal was exposed was a contributing cause of his laryngeal cancer.

The court additionally noted that even the temporal association of plaintiffs' exposure to AFM failed to give support for his causation theory. The record indicates that McDougal's cancer, when discovered, was 1.9 centimeters in size. The defendant contends that the appropriate doubling time would require 8.7 years. Plaintiffs disagreed with this theory and produced evidence that the doubling would occur within a range of 3.95 years to 5.9 years. The court resolved the dispute by observing that "the latency period cannot completely exclude the possibility of Mr. McDougal's getting his cancer by reason of his exposure to AFM while on the job. But the latency data creates one more negative for the plaintiff[s]." Id. at 975.

As a final factor weighing against admissibility, the court criticized the methodology of the plaintiffs' experts, stating that since they had failed to "identify a dosage level of AFM that is known to cause laryngeal cancer in humans . . . we are back to the temporal association: plaintiff was exposed to AFM and thereafter he developed laryngeal cancer. The plaintiff[s'] experts believe that [McDougal's] cancer was caused by AFM and, if it was, then certainly the exposure and dose were sufficient. This flawed logic is no substitute for reliable scientific proof of causation."Id. at 967.

The court concluded:

[P]roof of dosage is necessary in the case, but [the court] does not agree that the calculations of Dr. Valentine or Dr. Draughon would provide an adequate basis for a jury to determine [McDougal's] level of exposure or the dosage in this case. First, Dr. Draughon's position is, simply, that even if you accept plaintiff[s'] experts' approach and assumptions, the level of exposure to aflatoxin M-1 that they postulate has not been shown to cause laryngeal or any other cancer in humans. Second, the Court accepts Dr. Draughon's critique of plaintiff[s'] exposure and dosage calculations as accurate. . . . This finding leaves [McDougal] with clear evidence that he was exposed to some aflatoxin M-1 in the aerosol produced in the cheese-making process, but no evidence from which a jury could rationally quantify that exposure in terms of time or amount. Nor [have] plaintiff[s] even attempted to establish the level of exposure to AFM that would cause [McDougal's] cancer. So plaintiff[s] [are] really left with [their] "one-hit" "no threshold" theory.

Id. at 982 (citation omitted).

II.

Admission of expert testimony is governed by Federal Rule of Evidence 702, which states:

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.

Fed. R. Evid. 702. In Daubert, 509 U.S. at 588, the Supreme Court held that, consistent with the "liberal thrust" of the Federal Rules of Evidence, this rule replaced the more...