Appeals Court Upholds Summary Judgment Based on Daubert in Benzene Case

The Sixth Circuit last week upheld the dismissal of a plaintiff''s claim that benzene exposure caused her cancer. Pluck v. BP Oil Pipeline Co., No. 09-4572 (6th Cir.,  5/12/11).  The central issue was the exclusion of plaintiff's causation expert's opinion based on a "differential diagnosis" that failed to reliably rule in benzene exposure as a potential cause of plaintiff's cancer, and to rule out some other potential exposures.

This case arose from benzene contamination allegedly caused by gas-pipeline releases allegedly resulting in the seepage of gasoline into the surrounding soil and groundwater. Benzene, a component of gasoline, is a known carcinogen in sufficient doses under certain exposure circumstances, and is also ubiquitous in the ambient air and is a component or constituent of vehicle exhaust and cigarette smoke, said the court. Plaintiffs purchased a home in the area,  and used well water to drink, wash, shower, and irrigate their yard and garden. In October,  1996, plaintiffs say they noticed a gasoline odor in their home and water, and benzene was first detected in the well on their property in the amount of 3.6 parts per billion (“ppb”).  They began drinking bottled water in lieu of tap water, although they claim to have resumed drinking tap water upon the drilling of a new, deeper well. Between 1997 and May 2002, the new well tested negative for benzene twenty-two times.

Mrs. Pluck was diagnosed with Non-Hodgkins lymphoma (“NHL”) in 2002 at age forty-eight. She filed suit, alleging claims of strict liability for hazardous activity, negligence, and loss of consortium. To support their claims, plaintiff and spouse retained Drs. Joseph Landolph and James Dahlgren as experts on causation to demonstrate that benzene is generally capable of causing NHL and specifically caused Mrs. Pluck’s NHL. Defendant filed motions in limine to exclude the testimony of Dahlgren and Landolph on the grounds that their testimony failed to satisfy the standard for reliability set forth in Daubert. In particular, BP argued that Dr. Dahlgren’s testimony on specific causation was unreliable because he formulated a specific causation opinion without evidence of dose, and subsequently performed an unreliable dose reconstruction in an attempt to support his opinion.  Dahlgren then submitted a supplemental declaration in which he evaluated Mrs. Pluck’s illness under a "differential-diagnosis" methodology. The district court granted the motions, and plaintiff appealed.

In a toxic tort case, as here, the plaintiff must establish both general and specific causation through proof that the toxic substance is capable of causing, and did cause, the plaintiff’s alleged injury.  As to specific causation, the plaintiff must show that she was exposed to the toxic substance and that the level of exposure was sufficient to induce the complained-of medical condition (based on a dose-response relationship). Both causation inquiries involve scientific assessments that must be established through the testimony of a medical expert. Without this testimony, a plaintiff’s toxic tort claim will fail.

The Plucks had to concede that the expert Dr. Dahlgren did not establish dose; they instead argued that Dahlgren used differential diagnosis to determine specific causation. Defendant argued that Dr. Dahlgren did not apply differential diagnosis in either his expert opinion or his deposition, but did so only in an untimely supplemental declaration filed five months after the deadline for expert reports. And in any event, his approach was flawed. The Sixth Circuit has recognized differential diagnosis, properly done, as an appropriate method for making a determination of causation for an individual instance of disease. Differential diagnosis -- originally a standard technique for determining what disease caused a patient's symptoms -- has been adapted in some courts as an acceptable scientific technique for identifying the cause of a medical problem by eliminating the likely causes until the most probable one is isolated. A physician who applies differential diagnosis to determine causation considers all ("rules in") relevant potential causes of the symptoms and then eliminates ("rules out") alternative causes based on a physical examination, clinical tests, and a thorough case history.

Even in courts that accept this adapted method, not every opinion that is reached via a differential-diagnosis method will meet the standard of reliability required by Daubert.  Calling something a “differential diagnosis” or “differential etiology” does not by itself answer the reliability question but prompts at least three more:

(1) Did the expert make an accurate diagnosis of the nature of the disease?

(2) Did the expert reliably rule in the possible causes of it?

(3) Did the expert reliably rule out the rejected causes?

If the court answers “no” to any of these questions, the court must exclude the ultimate conclusion reached.

Here the court agreed that Dahlgren could not reliably “rule in” benzene exposure as the cause of Mrs. Pluck’s NHL. In recognition of the fact that benzene poses a health concern at certain levels of exposure, the EPA has stated that the maximum permissible contaminant level for benzene in
drinking water is 5 ppb. 40 C.F.R. § 141.61(a)(2). Dahlgren, however, did not ascertain Mrs. Pluck’s level of benzene exposure, nor did he determine even whether she was exposed to quantities of benzene exceeding the EPA’s safety regulations. The levels of benzene in the Plucks’ wells never exceeded the maximum permissible contaminant level of 5 ppb designated by the EPA.

Dahlgren’s opinion that Mrs. Pluck’s “low-level exposure” to benzene caused her NHL was thus not grounded in “sufficient facts or data,”  nor did it reflect the “reliable principles and methods” required by Rule 702. It was, instead, pure conjecture.  Although the Plucks argued that the district court required too much specificity regarding Mrs. Pluck’s dose, this argument was also without merit. The mere existence of a toxin in the environment is insufficient to establish causation without proof that the level of exposure incurred could cause the plaintiff’s symptoms. See also McClain v. Metabolife Int’l, Inc., 401 F.3d 1233, 1242 (11th Cir. 2005) (causation “requires not simply proof of exposure to the substance, but proof of enough exposure to cause the plaintiff’s specific illness”).

Finally, even if Dr. Dahlgren had properly “ruled in” benzene exposure as the cause plaintiff's NHL, he failed to “rule out” alternative causes of her illness, as is required under the differential-diagnosis methodology. See also Wills v. Amerada Hess Corp., 379 F.3d 32, 50 (2d Cir. 2004) (expert’s opinion suffered from a “fatal flaw” when he acknowledged that cigarettes and alcohol were risk factors for developing squamous-cell carcinoma but failed to account for these variables in concluding that decedent’s cancer was caused by exposure to toxic chemicals such as benzene and PAHs).  In this case, Dahlgren acknowledged in his deposition that Mrs. Pluck was
exposed to other sources of benzene, from her extensive smoking habit and from other organic solvents.  Yet, Dr. Dahlgren neither identified these other solvents nor determined Mrs. Pluck’s potential level of exposure to these other possible sources of benzene.Thus, Dahlgren failed to “rule out” alternative causes of Mrs. Pluck’s NHL.

The court of appeals determined that the district court did not abuse its discretion in concluding that the expert did not perform a reliable differential diagnosis.  And summary judgment properly followed.

 

Welding Fume MDL Court Releases "Trial Template"

The Judge overseeing the Welding Fume Products Liability MDL Litigation has issued a “Trial Template” to assist transferor courts in handling the 3,900 remaining cases in the future.  In re: Welding Fume Products Liability Litigation, MDL No. 1535 (N.D. Ohio).

The document outlines the proceedings that have occurred in this MDL since its 2003 inception,
and summarizes the court’s pretrial rulings applicable to every MDL case. (All of this MDL court's written Orders cited in the document are available through the MDL court’s site.)  The stated purpose of the document is to assist trial judges in transferor courts who may preside over the trial of an individual welding fume case, after the Judicial Panel on Multi-District Litigation remands the
case from the MDL court back to the transferor court.

(Another good source on this mass tort for the interested reader is Jowers v. Lincoln Elec. Co., 608 F.Supp.2d 724 (S.D. Miss. 2009), in which the court reviewed all of the parties’ evidence in the context of resolving defendants’ post-judgment motions, filed after the jury reached a rare plaintiff’s verdict in the fourth MDL bellwether trial.)

Key points: since the MDL was created in the U.S. District Court for the Northern District of Ohio in June 2003, more than 9,800 cases have been transferred from other courts, and 2,700 have been removed to or directly filed with the court. Voluntary dismissals, remands and other events have reduced the number of pending cases to approximately 3,900. The gravamen of the complaint in each of these cases is that manganese contained in the fumes given off by welding rods has caused the plaintiff to suffer neurological injury, and the defendant manufacturers of these welding rods failed to warn of this hazard. At trial, defendants typically interpose some or all of the following fact-based defenses: (1) the warning language defendants used was adequate; (2) the plaintiff did not prove he used a particular defendant’s welding rods; (3) the plaintiff did not prove he saw a particular defendant’s warnings; (4) the plaintiff did not prove his neurological condition was caused by exposure to welding fumes; (5) the plaintiff’s neurological condition is not manganese-induced "Parkinsonism," it is something else (e.g., psychogenic movement disorder); (6) the defendants are immune pursuant to their role as government contractors; (7) the defendants are not liable because the plaintiff’s employer was a learned intermediary; (8) the defendants are not liable because the plaintiff was a sophisticated user; (9) the plaintiff did not prove that a better warning would have made any difference; (10) the plaintiff is, to some degree, responsible for his own injuries under the theories of contributory negligence, comparative negligence, or assumption of the risk; and (11) punitive damages are not available because the plaintiff did not present clear and convincing evidence of gross negligence.

The MDL court presided over six bellwether trials and is now in the process of suggesting remand to transferor courts of cases that have become close to trial-ready, the judge said. The court has so far applied the laws of five states in MDL bellwether trials: Mississippi, Texas, South Carolina, California, and Iowa. The parties sometimes, but not always, have agreed on which state’s law applies. In cases of disagreement, the choice-of-law analysis a transferor court will have to apply is likely to be fact-specific.

The court has granted summary judgment to certain defendants (MetLife & Caterpillar) in all welding fume cases. Further, the Court entered a “Peripheral Defendant Dismissal Order,” dismissing without prejudice all defendants in every case except those against whom a given plaintiff is most likely to proceed at trial. Still remaining as defendants in virtually every case are five of the biggest welding rod manufacturers: (1) Lincoln Electric Company, (2) BOC Group (formerly known as Airco) (3) ESAB Group, (4) TDY Industries (formerly known as Teledyne Industries and Teledyne McKay), and (5) Hobart Brothers Company. Defendant-specific discovery in each case may lead to dismissal of some of these five defendants, and possibly to renaming of some previously-dismissed defendants, the court observed. 

Regarding discovery, the parties have engaged in huge amounts of generic discovery directed at
information potentially relevant to every case. This includes, for example, the defendants’ alleged historical knowledge of the hazards posed by welding fumes, the warnings defendants provided to welders over time, and the state of medical and scientific knowledge regarding neurotoxicity of manganese in welding fumes. For the most part, the parties have completed all general discovery. To prepare for trial in a specific welding fume case, the parties must engage in substantial case-specific discovery directed at information relevant to the individual plaintiff’s particular claims and circumstances. This discovery typically will address the plaintiff’s employment history, medical history, and welding experiences. The court observed that at least some of this plaintiff-specific discovery may not occur until after the MDL court has remanded the case to the transferor court. Accordingly, a transferor court may need to oversee some aspects of case-specific discovery.

As to plaintiffs, about ten years ago, the national plaintiffs’ bar engaged in a concerted effort to notify welders that, if they suffered from a movement disorder, their neurological injury might be caused by exposure to welding fumes. The MDL court then imposed several obligations on plaintiffs’ counsel to ensure they intend to actually try the cases they filed. These additional obligations include the filing of: (1) a “Notice of Diagnosis” of neurological injury, signed by a medical doctor; and (2) a “Certification of Intent to Try the Case,” to be submitted by plaintiff’s counsel following initial medical records discovery. These obligations have winnowed the plaintiffs’ cases substantially, so the MDL court believes that there is some likelihood that a case remanded to a transferor court will go to trial.

On the expert front, the parties sought to introduce at trial testimony from a plethora of experts in a number of fields, including neurology, neuro-pathology, neuro-psychology, neuro-radiology, epidemiology, bio-statistics, industrial hygiene, industrial engineering, chemistry, materials science, toxicology, warnings, corporate ethics, military specification and procurement, economics, government lobbying, and ancient corporate documents. Early in this MDL, the court held a multi-day Daubert hearing to determine the admissibility of opinions offered by these experts. Further, the court engaged in additional analyses of the admissibility of expert testimony prior to each MDL
bellwether trial.

Before each MDL bellwether trial, the parties filed numerous motions in limine addressing the admissibility of various pieces of evidence, ranging from critical documents to relatively short comments made by witnesses. The court reviews each of those rulings in this latest document.  Similarly, the court had ruled on a number of motions for summary judgment as a matter of state and federal law. These motions are also described in the document.  For example, to prevail on his product liability claims against a particular manufacturing defendant, a welding fume plaintiff must show he actually used that manufacturer’s products. Because many plaintiffs worked as welders for a variety of employers in different locations over many years, and because welding rods are somewhat fungible, the discovery of product identification evidence can be difficult, and the results less than clear, said the court. Whether a given defendant is entitled to judgment as a matter of law based on lack of product identification is a highly fact-specific question, and the answer as to certain defendants in certain cases may not become clear even until after trial.

Finally, the court provides a number of useful appendices and charts, including MDL Bellwether Trial Result Summary and MDL Bellwether Trial Witness Chart.