Seventh Circuit Court of Appeal Revisits Rules on Scientific Evidence

1024px-HAZMAT_trainingIn mass tort cases, one of the toughest elements for plaintiffs to prove is that the product’s harmful nature caused the plaintiffs’ injuries. This is especially true in cases involving exposure to harmful chemicals. In our modern environment, there are a host of chemicals that we encounter on a daily basis, whether we know it or not. Determining whether a chemical is harmful and whether that chemical was the cause of the plaintiff’s alleged injuries can be a challenge.

The recent case of C.W. ex rel. Wood v. Textron, Inc. touched on this subject and provided the Seventh Circuit Court of Appeal with an opportunity to review the types of scientific evidence that parties may offer in relation to proving both specific and general causation in a mass tort case.

In that case, the plaintiffs alleged that the defendant released a quantity of carcinogenic vinyl chloride chemical into the plaintiffs’ water supply in Rochester, Indiana and that their two children, adopted infants, suffered physical injuries as a result. According to the plaintiffs, the infants started exhibiting serious health problems after being exposed to the chemical, including vomiting, bloody stool, and other issues related to their gastrointestinal, neurological, and immunological systems. Shortly after discovering that the chemical might be the cause of the infants’ health conditions, the plaintiffs relocated and the infants’ health conditions improved. The plaintiffs brought a lawsuit against the defendant, alleging that the defendant was responsible for the infants’ exposure to vinyl chloride and that the exposure subjected them to an increased risk of cancer-related illnesses.

Discovery in the case lasted roughly four years. When the parties finally reached expert witness discovery, the defendant filed a motion seeking to bar three of the plaintiffs’ medical experts, and the trial court granted the motion. After barring the experts’ testimony, the trial court concluded that the plaintiffs were no longer able to prove either (1) that the chemical had the capacity to cause the infants’ injuries, i.e., general causation; or (2) that the chemical was the cause in fact of the infants’ injuries, i.e., specific causation. Relying on this reasoning, the trial court granted the defendant’s motion for summary judgment.

On appeal to the Seventh Circuit, the court examined each of the plaintiffs’ theories of causation. First, the plaintiffs contended that the defendant violated the government’s standards and regulations pertaining to the chemical and that this caused the infants’ injuries. The Seventh Circuit rejected this reasoning, relying on earlier holdings stating that exceeding government regulations is not sufficient evidence to prove causation.

Next, the court touched on the experts’ use of extrapolated studies. During scientifically complex trials, experts often rely on an extrapolation to establish causation, arguing that they can scale down certain studies examining excess exposures of long periods of time to much lower exposures and smaller timeframes. The Seventh Circuit rejected the experts’ extrapolations offered in the present case, finding that the studies they used for the basis of their extrapolations were inapplicable, including an animal study involving rats.

Finally, the Seventh Circuit discussed differential etiology, which involves identifying the cause of an injury by process of elimination. This approach allows experts to consider a wide range of possible causes and rule out each one until they are left with the true cause of the injuries. The Seventh Circuit rejected the lower court’s ruling that differential etiology can never be used to prove general causation, holding instead that the plaintiffs should have a chance to use this method to help prove, or prove entirely, both specific and general causation.

If you or someone you know has suffered injuries due to toxic chemical exposure, you may be entitled to compensation. From their main office in Chicago, the dedicated toxic tort attorneys at Moll Law Group have represented many afflicted plaintiffs throughout the country, including in California and Texas, and we are ready to fight for your rights. Call us now at 312-462-1700 or contact us online to set up a free consultation.