Guest Commentary

Nick Hendrix, a 2012 Judge K.K. Legett Fellow at the Washington Legal Foundation and a student at Texas Tech School of Law.

Asbestos has been the source of countless medical studies, news stories, and lawsuits concerning its negative effects on the human body. In asbestos litigation, plaintiffs must prove that the exposure is a “substantial factor” in the injury. Medical science has established a clear link between the exposure to large amounts of asbestos and the development of various cancers, most often mesothelioma. A theory often employed by plaintiffs, and one not clearly established by science, is the “any-fiber” theory asserting that exposure to a single, microscopic asbestos fiber is enough to satisfy the legal requirement of substantial causation. A unanimous Pennsylvania Supreme Court has addressed and rejected this theory, striking a significant blow against novel asbestos litigation in a state where many such cases have been filed.

Betz v. Pneumo Abex LLC originated in 2005 when Charles Simikian sued numerous parties, alleging that exposure to the parties’ products throughout his 44-year career as an auto mechanic caused his mesothelioma.  Plaintiff, through his expert witness Dr. Maddox, relied on the “any-fiber” theory to establish legal causation of his cancer. The various defendants then challenged Maddox’s testimony under Pennsylvania’s legal principles for expert scientific testimony, asserting that the “any-fiber” theory of legal causation was not “generally accepted.”

Dr. Maddox countered by asserting that each fiber of asbestos contributes to the overall risk of developing mesothelioma, and, therefore, each fiber is a substantial cause of the development of cancer. In an analogy, Dr. Maddox described the theory in terms of dropping marbles into a glass of water until it overflows. Both the first and last marbles (asbestos fibers) are substantial causes of the eventual overflow (cancer). Defendants’ experts attacked Maddox’s theory on the grounds that he failed to follow the scientific method, and simply jumped from hypothesis to conclusion. Further, the defense experts testified that Maddox’s theory was logically inconsistent in that Maddox had admitted that potency, concentration, and duration of exposure were also important, a position that the experts found irreconcilable with the “any-fiber” theory.

The trial judge upheld the defendants’ challenge, excluded Maddox’s testimony, and granted summary judgment in favor of the defendants. The trial judge found there was an “analytical gap” in Maddox’s theory, and ruled Maddox’s analysis was not consistent with generally accepted methodology. The plaintiff then appealed and won at the Superior Court level on the grounds that the trial judge abused his discretion in excluding Maddox’s testimony.

The Supreme Court of Pennsylvania reversed the judgment of the Superior Court. The Court began by discussing the controversial nature of the “any-fiber” theory and the significant impact it has in asbestos litigation by removing the need to prove legal causation by other means. The Court then addressed Maddox’s inability to adequately explain the leap from high-dose exposure to his “any-fiber” theory of causation. Further, the Court was concerned with Maddox’s inconsistent positions claiming that a single fiber is substantially causative, while maintaining that mesothelioma is dose responsive with respect to asbestos. Returning to Maddox’s marble analogy, the Court pointed out that unlike marbles, asbestos fibers are non-uniform in shape and are microscopic in size. The Court found the analogy less convincing given that it is hard to attribute water overflowing to a single, microscopic fiber.

In ruling that the testimony was excludable, and that the “any-fiber” theory could not establish legal causation, the Pennsylvania Supreme Court has raised the bar for plaintiffs suing for asbestos-related injuries. No longer will single fiber exposure theories subject defendant’s to legal causation; rather, plaintiff’s must now satisfy that exposure to a particular defendant’s asbestos product was a “substantial factor” in the plaintiff’s injury through other, more stringent theories of causation.