When is an Expert Opinion on Causation Admissible in a Toxic Tort Case?

Two of the most important aspects of any toxic tort case are the expert opinions presented by each side. Whether a chemical actually causes the health conditions experienced by the plaintiffs, whether the product produced the health condition in the instant case, and whether the product actually carries a sufficient quantity of the substance to create a health risk are all highly technical questions that rely on scientific expertise to answer. How do New York courts evaluate whether an expert’s opinion on causation is sound, admissible, and convincing? A New York magistrate judge recently issued a detailed and illuminating opinion on the admissibility of expert opinions in toxic tort matters. Continue reading for details about the ruling and the case, and reach out to an experienced New York toxic torts defense attorney for help defending against toxic tort claims.

Reliable Expert Opinion Requires Detailed Analysis Backed By a Lot of Science

The matter of Sarkees v. E. I. DuPont de Nemours and Company et al. involves a toxic tort claim by a former employee of Goodyear Tire & Rubber Company. He alleged that his work at Goodyear exposed him to a substance called ortho-toluidine (“OT”), which has been investigated for decades as a suspected human carcinogen. The plaintiff blamed his bladder cancer on prolonged exposure to OT and sued.

According to Parker v. Mobil Oil, a seminal New York Court of Appeals case, an expert’s opinion in a toxic tort matter must set forth a scientifically reliable explanation for both “specific” and “general” causation. That is, an opinion must establish two things:

● General causation: The toxin is capable of causing the particular illness suffered by the plaintiff.
● Specific causation: The plaintiff was exposed to sufficient levels of the toxin to cause the illness.
The Sarkees court evaluated various methods by which general causation could be established, including microbial and animal clinical studies, case reports, and epidemiology studies, the latter being the strongest evidence. Once general causation is established, then the expert must show specific causation, including showing that: 1) the plaintiff was exposed to the chemical; 2) within a reasonable amount of time to the onset of the plaintiff’s condition; 3) other potential causes of the condition are accounted for; and 4) all available evidence is consistent with causation.

Here, the court found the plaintiff’s general causation expert credible. The expert was qualified (including decades as a Ph.D. toxicologist), and he reviewed and presented decades of animal study evidence showing a statistically significantly higher incidence of tumors, bladder cancer, or other cancers for animals exposed to OT. The court took pains to explain how animal study evidence can be reliable for demonstrating carcinogens that have the same effect on humans, and what types of holes other experts have left in their opinions regarding such studies (such as meta-analyses that lacked concrete evidence of exposure and causation).

The court also found the plaintiff’s specific causation expert opinion admissible. Evidence from the amount of OT in the atmosphere of the plaintiff’s workplace years after he worked there was still persuasive to show the likely amount of the chemical in the air when the plaintiff did work there, demonstrating exposure. Regarding whether the plaintiff was exposed to OT for long enough to get cancer, the expert presented studies showing that several months of exposure were sufficient to have carcinogenic effects. The expert also went through the various potential alternate causes of the plaintiff’s bladder cancer and methodically dismissed them one-by-one. For these reasons, the court admitted the expert’s opinion.

For experienced, knowledgeable, and detail-oriented legal advice and representation regarding a New York toxic tort or insurance defense claim, contact the Islip offices of Richard A. Fogel at 516-721-7161.