With insolvencies having removed the potentially responsible parties from the courtroom, claimants seeking redress for asbestos-related disease now focus upon entities whose products may have contained some trace amounts of asbestos, usually bound into the product in some way so that the products could potentially emit few, if any, dangerous asbestos fibers. In order to impose liability upon defendants whose products did not release dangerous asbestos, plaintiffs’ counsel have strained to develop extraordinary and novel theories of product-liability causation law. One such extension is the “single-fiber” theory, under which an expert, typically a medical professional, opines that each and every exposure to a single asbestos fiber is deemed to be a substantial contributing factor in causing the plaintiff’s disease. Less than a year ago, the Pennsylvania Supreme Court severely curtailed the use of the “single-fiber” theory in Gregg v. V-J Auto Parts, Co., 943 A.2d 216 (Pa. 2007).
In Gregg, the Pennsylvania Supreme Court repudiated plaintiff’s “each-and-every exposure” expert testimony, noting that “we do not believe that it is a viable solution to indulge in a fiction that each and every exposure to asbestos, no matter how minimal in relation to other exposures, implicates a fact issue concerning substantial-factor causation in every ‘direct-evidence’ case.” Id. at 227-28. The court recognized further that asbestos plaintiffs’ expert testimony in this regard constitutes “generalized opinions,” insufficient to create a jury question in a case where exposure to the defendant’s product is de minimus. Id. at 228. Thus, after Gregg, a plaintiff cannot survive summary judgment by claiming a de minimus exposure to a product and relying on expert testimony opining that exposure to a single asbestos fiber caused his disease.
On September 24, 2008, Judge Alan Tereshko-the coordinating judge for the mass tort docket in Philadelphia County-applied Gregg to determine that single-fiber expert testimony does not meet the admissibility requirements set forth in Frye v. United States, 293 F. 1013 (D.C. Cir. 1923). Under Frye, for expert testimony to be considered admissible, the proponent of the evidence must prove that the expert’s methodology is generally accepted by scientists in the relevant field as a means of reaching the conclusion to which the expert will testify at trial. Id. at 1014. In In re Asbestos Litigation (Motion Control No. 084682), Judge Tereshko rejected the testimony of three plaintiffs’ experts, all of whom opined that each and every exposure to a single asbestos fiber was a substantial contributing factor in causing the plaintiff’s disease, because the testimony lacked any coherent methodology.1 See Op., at 54. According to Judge Tereshko, the experts based their opinions on a form of dubious inductive logic that “[i]f one breath of asbestos can cause a disease then every breath causes it.” Such logic is faulty because it is undisputed that the general population is exposed to asbestos in one form or another (e.g., asbestos in the ambient air) and some get an asbestos-related disease, while others do not.
As it now stands, to prevail at trial, asbestos plaintiffs must show a genuine causal nexus between a defendant’s product and a plaintiff’s injuries. Moreover, because the admissibility of expert evidence is a matter of procedure that should be governed by Pennsylvania law in Pennsylvania courts, plaintiffs cannot circumvent it by arguing that the law of another jurisdiction applies to the substantive causation element of any claim pending in a Pennsylvania court.
1. Judge Tereshko specifically denounced the experts’ reliance upon such purported methodologies as chemical structure analysis or animal studies, as being incoherent and lacking any consideration of scientific epidemiology.