The Maryland Court of Appeals decided this morning Chesson v. Montgomery Mutual, a mold exposure workers’ compensation case. I don’t handle mold or workers’ comp cases. But this case has implications for any tort cases involving the question of what opinions an expert can render at trial.
Claimant in this case sought compensation for exposure to mold that caused neurocognitive and musculoskeletal problems. The trial court in Howard County allowed testimony from plaintiffs’ expert that this mold exposure caused injury. The expert based his opinion on a differential diagnosis which basically means process of elimination. The Claimant won at trial and the defendant insurance company appealed.
Certainly, the expert’s opinion had some flaws that the defendant readily exposed on cross examination. He did not test the buildings for mold exposure because the presence of a musty smell alone was enough. The basis for his opinion was that these patients were in mold invested buildings, removed from the area, and then returned.
The expert’s conclusions are based on the fact that the subjects got better when taken out of the area and worse when exposed again. Certainly, that is a theory that works for concluding that you better call someone if we are taking about your child’s bedroom. But the question here is whether this methodology passes Frye-Reed. The Maryland high court said that it did not.
Ultimately, what we have is a sketchy testing in a very controversial toxic exposure case. Mold litigation is propelled by endless media coverage which has led to a heightened public awareness of the concerns. Courts around the country are grappling the challenge of just how to deal with these cases. Still, there is a considerable amount of uncertainly about the type and extent of the injuries that can be caused by mold exposure. The Maryland courts are giving a real heads up about how far plaintiffs’ counsel has to go to show that there is scientific consensus about the the effects of exposure.
The opinion provides a rich analysis of what is required under Frye-Reed and should be read by anyone who is trying complex medical causation cases.