The National Association of Manufacturers and other business groups filed a friend of the court brief in Pennsylvania last week challenging the admission of junk science in support of a lawsuit claiming illness from asbestos exposure. The narrow interest is clear: Allowing bogus scientific claims makes it more difficult for manufacturers to defend themselves in product liability suits. But junk science also debases our entire judicial system.

At issue in Betz v. Pneumo Abex et al., now on appeal to the Supreme Court of Pennsylvania, is the validity of unchallenged testimony claiming that any exposure to asbestos on the job, no matter how small, is a “substantial factor” in causing mesothelioma.  Our amicus brief urges the court to reject testimony based on this “any exposure” theory, which contrasts sharply with normal causation testimony. The trial court called the theory junk science, as have many other courts, but an intermediate appellate court reversed because the judge did not constrain his ruling strictly to the arguments made by the defendants.

The brief (available here) argues that the judge properly exercised his authority and independent judgment to identify logical and scientific errors in the “any exposure” theory. The theory shuns the bedrock principle of toxicology that “the dose makes the poison,” and ignores the fact that small doses of even toxic substances may cause no harm. The “any exposure” theory could subject companies that handle any products with any degree of toxicity to expansive liability.  The theory is inconsistent with asbestos science and epidemiology and runs counter to the vast majority of other court opinions.

The National Chamber Litigation Center has more on the litigation here. Nathan A. Schachtman, Esq., who specializes in expert witnesses, offers further analysis in this 2010 blog post, “Betz v. Pneumo Abex: the Recrudescence of Ferebee in Pennsylvania.”