Recent decisions have excluded plaintiffs’ expert opinions that fail to estimate actual exposure and prove it was sufficient to cause injury.
Recent federal court rulings in toxic tort litigations have stressed the importance of the dose-response relationship and the need to carefully evaluate the level of exposure to pass the Daubert standard for expert witness admissibility under the Federal Rules of Evidence 702. Under the Daubert standard, courts must assess whether the reasoning or methodology underlying the expert testimony is scientifically valid and whether those reasons or methodologies can be properly applied to the facts at issue. Dose-response methodology studies the relationship between the quantity of a substance (dose) and its overall effect (response) on a person, and is “the hallmark of basic toxicology.” The courts continue to scrutinize experts’ dose-response analysis to determine the reliability of that testimony on specific causation. The following three cases highlight the importance of a thorough dose-response analysis in any expert opinion that evaluates a plaintiff’s exposure and harm.