“It is only the dose which makes a thing poison.”
A fundamental tenet of toxicology is that “the dose makes the poison.” Federal Judicial Center, Reference Manual on Scientific Evidence, Reference Guide on Toxicology 403 (2000). Thus, in toxic tort cases, courts routinely require plaintiffs to demonstrate not just some exposure to an alleged harm but “evidence from which the trier of fact could conclude that the plaintiff was exposed to levels of toxins sufficient to cause the harm complained of.” Wintz v. Northrop Corp., 110 F.3d 508, 513 (7th Cir. 1997); Wright v. Willamette Indus., Inc., 91 F.3d 1105, 1107 (8th Cir. 1996). In fact, “[d]ose is the single most important factor to consider in evaluating whether an alleged exposure caused a specific adverse effect.” David L. Eaton, “Scientific Judgment and Toxic Torts: A Primer in Toxicology for Judges and Lawyers,” 12 J.L. & Pol’y 5, 11 (2003). This article addresses some recent cases that several courts have issued, offering a consensus that no matter what the plaintiff’s expert in an asbestos case calls it, the “every exposure” opinion should be excluded because it lacks a sound toxicological basis and there is no reliable scientific methodology employed in reaching it.