A split appellate panel of the Superior Court of Pennsylvania rejected the admissibility of the “any breath” theory of asbestos causation, and reversed a $14.5 million verdict against three welding product manufacturers. The case, Nelson v. Airco Welders Supply, et al., was brought on behalf of a decedent who worked as a welder, labourer, and mechanic at a steel plant for 33 years, during which he was exposed to various asbestos-containing products. Two years after leaving his job, the decedent was diagnosed with mesothelioma, and he died about one year later. At trial, the court admitted – against the defendants’ objections – the plaintiffs’ expert’s testimony that “every exposure must be considered a cause of the disease” (the “any-breath” theory); the jury returned a verdict in favour of the plaintiffs. While the defendants’ appeal was pending, however, the Pennsylvania Supreme Court decided Betz v. Pneumo Abex, LLC, 44 A.3d 27 (Pa. 2012), a test case for the any-breath theory. In Betz, the court suggested that the any-breath opinion – which would effectively relieve the plaintiff from proving specific causation or the substantiality of their exposure – was more likely based on the “best estimate,” “gut instinct,” or “educated guess” of the expert, rather than sound scientific principles logically applied. The expert in Betz, for example, claimed that the theory was rooted in epidemiological science, but avoided specific questions regarding epidemiology. Similarly, the plaintiff’s expert in Nelson conducted very little scientific analysis, but testified that “it is accepted or believed that there are no innocent respirable asbestos fibers.” The appellate panel held that admitting such testimony was reversible error, and ordered a new trial.

The opinion is Nelson v. Airco Welders Supply, et al., No. 856 EDA 2011 et seq. (Pa. Sup. Ct., Sept. 5, 2013) (reversing judgment for plaintiff).