A federal court recently excluded the specific causation opinions of a plaintiff's expert who asserted the defendant was liable in an asbestos case under a version of the “each and every exposure” theory. See Comardelle v. Pennsylvania General Ins. Co., No. 13-6555 (E.D. La., 1/05/15).

Plaintiffs alleged that decedent was exposed to asbestos and asbestos-containing products manufactured, distributed, and sold by defendants during the course of his employment from 1963 through 1979.  As a result of these exposures, the decedent allegedly contracted mesothelioma, which was first diagnosed in approximately September, 2013.

Among a myriad of other claims, plaintiffs alleged that he was exposed to asbestos-containing coatings, sealants, and mastics manufactured, distributed, and sold by Amchem, including an adhesive called Benjamin Foster.  Plaintiffs proposed to call Dr. Samuel P. Hammar as an expert witness to opine that Benjamin Foster was a substantial contributing factor to the development of the mesothelioma. Amchem moved to exclude or limit this specific causation opinion. Specifically, Amchem argued that Hammar's testimony was a version of the “every exposure” theory opinion, not allowable under Fed. R. Evid. 702 and Daubert v. Merrell Dow Pharms, Inc., 509 U.S. 579 (U.S. 1993).  Rule 702 of the Federal Rules of Evidence governs the admissibility of expert witness testimony. As readers know, Rule 702 provides:

A witness who is qualified as an expert by knowledge, skill, experience, training, or education may testify in the form of an opinion or otherwise if:

  1. the expert's scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue;
  2. the testimony is based on sufficient facts or data;
  3. the testimony is the product of reliable principles and methods; and
  4. the expert has reliably applied the principles and methods to the facts of the case.

To qualify as an expert, the witness must have such knowledge or experience in the field or calling as to make it appear that his opinion or inference will probably aid the trier in his search for truth. See United States v. Hicks, 389 F.3d 514, 524 (5th Cir. 2004). Additionally, Rule 702 states that an expert may be qualified based on "knowledge, skill, experience, training, or education." Hicks, 389 F.3d at 524; see also Kumho Tire Co., Ltd. v. Carmichael, 526 U.S. 137, 147 (1999) (discussing witnesses whose expertise is based purely on experience).  A district court should refuse to allow an expert witness to testify if it finds that the witness is not qualified to testify in a particular field or on a given subject. Huss v. Gayden, 571 F.3d 442, 452 (5th Cir. 2009).

The U.S. Supreme Court's decision in Daubert provides the basic analytical framework for determining whether expert testimony is admissible under Rule 702.  See Pipitone v. Biomatrix, Inc., 288 F.3d 239, 243 (5th Cir. 2002). A number of nonexclusive factors may be relevant to the reliability inquiry, including: (1) whether the technique has been tested, (2) whether the technique has been subjected to peer review and publication, (3) the potential error rate, (4) the existence and maintenance of standards controlling the technique's operation, and (5) whether the technique is generally accepted in the relevant scientific community. Burleson, 393 F.3d at 584. The reliability inquiry must remain flexible, however, as "not every Daubert factor will be applicable in every situation; and a court has discretion to consider other factors it deems relevant." Guy v. Crown Equip. Corp., 394 F.3d 320, 325 (5th Cir. 2004); see Runnels v. Tex. Children's Hosp. Select Plan, 167 F. App'x 377, 381 (5th Cir. 2006). 

In a number of cases, plaintiffs and their experts have advanced the argument that every exposure to asbestos is a factor in producing their illness. See Joseph Sanders, The "Every Exposure" Cases and the Beginning of the Asbestos Endgame, 88 Tul. L. Rev. 1153, 1157 (2014). As summarized by the courts addressing the admissibility of such opinions, the "every exposure" theory "posits that any exposure to asbestos fibers whatsoever constitutes an underlying cause of injury to the individual exposed." Krik v. Crane Co., No. 10-7435, 2014 WL 7330901, at *2 (N.D. Ill. Dec. 22, 2014); see also Davidson v. Ga. Pac. LLC, No. 12-1463, 2014 WL 3510268, at *2 (W.D. La. July 14, 2014).

Dr. Hammar's proposed specific causation testimony here was an example of this "every exposure" theory. In his expert report, Dr. Hammar opined that "all asbestos fibers inhaled by an individual that reach the target organ have the potential to contribute to the development of lung cancer, mesothelioma, and other asbestos-related diseases." At his deposition, he went further and opined that "all of the exposures that that individual had who developed mesothelioma, all of those would have contributed to cause his mesothelioma." Accordingly, Dr. Hammar opined based on this "every exposure" theory that if Comardelle was exposed to asbestos released from Amchem or Benjamin Foster adhesives, those exposures would have been a substantial contributing cause of his disease.

Amchem then moved to exclude Dr. Hammar's testimony that exposure to its product was a substantial factor in causing Comardelle's mesothelioma. According to Amchem, this "every exposure" theory opinion did not pass muster under Rule 702. Amchem criticized as wholly unsupported Dr. Hammar's leap from the general causation premise that every asbestos exposure increases the risk of mesothelioma, to the specific causation opinion that Comardelle's exposure to this product necessarily caused or contributed to his mesothelioma. Amchem also faulted Dr. Hammar for failing to consider any facts or data specific to Comardelle's exposure to this particular product.

The court noted several recent "every exposure" decisions in other courts.  In Smith v. Ford Motor Co., the district court excluded Dr. Hammar's opinion that a plaintiff's exposure to brake dust caused his mesothelioma because "each and every exposure to asbestos by a human being who is later afflicted with mesothelioma, contributed to the formation of the disease." No. 08-630, 2013 WL 214378, at *1 (D. Utah Jan. 18, 2013). The Smith court held that opinion to be inadmissible and agreed with the growing number of published opinions from other courts that have reached a similar result: that the every exposure theory as offered as a basis for legal liability is inadmissible speculation that is devoid of responsible scientific support. Accord Anderson v. Ford Motor Co., 950 F. Supp. 2d 1217 (D. Utah 2013).

In Davidson v. Georgia Pacific LLC, the district court likewise rejected a causation opinion based on the "every exposure" theory, concluding that the theory is not testable and consequently cannot have an error rate, thus failing to satisfy two Daubert factors. 2014 WL 3510268, at *5. The court also faulted the expert for failing to rely on any data that would show that any particular defendant's product actually caused plaintiff to develop mesothelioma.

The court agreed with Amchem that Dr. Hammar's proposed specific causation opinions in this case were unreliable and inadmissible. Although there may be no known safe level of asbestos exposure, this does not support Dr. Hammar's leap to the conclusion that therefore every exposure a plaintiff had to asbestos must have been a substantial contributing cause of his mesothelioma. This kind of blanket specific causation opinion was not based on or tied to the specific facts and circumstances of any of Comardelle's exposures to asbestos and it ignored any differences or nuances of duration, concentration, exposure, and the properties of the fibers to which he may have been exposed.

Instead of explaining how Dr. Hammar could reliably opine that Benjamin Foster was a cause of Comardelle's mesothelioma, plaintiffs referred cursorily to a broad array of cases, studies, and regulatory materials. But none of those citations plugged the impermissible gap in Dr. Hammar's reasoning from the general causation proposition that exposure to asbestos increases the risk of mesothelioma, to the specific causation opinion that in this case Comardelle's exposure to Benjamin Foster  was a cause of his mesothelioma giving rise to liability. See, e.g., Anderson, 950 F. Supp. 2d at 1225 (excluding testimony despite plaintiff's citation to numerous scholarly articles and scientific studies because those materials were not specific to the type of exposure).

Accordingly, the court concluded that Dr. Hammar's specific causation opinions as to Benjamin Foster (and all other exposures at issue in this case), were an unreliable product of the "every exposure theory" and must be excluded.