Proving a causal link between toxin exposure and resulting injury is a hallmark problem in toxic tort cases. Emerging neuroscience has proven a useful tool in some cases providing stronger causal proof of the connection between toxin and injury. In cases involving in utero exposure, the difficulties persists. Some argue that until the science improves, PET or SPECT imaging should not be used to prove toxic torts. Several white papers have studies this issue in some detail, arguing that the use of neuroimaging to demonstrate cause and effect is premature. Nevertheless, several studies in the past several years provide strong evidence of specific links between toxic exposure and brain injuries, particularly for the developing brain.

The case today provides an interesting read about the challenges presented in proving the causal link between toxic exposure in utero and brain damage. The case failed on the issue of causation, with significant expert testimony on both side about the effects of the toxin, the levels needed to cause significant brain damage, and whether neuroimaging actually revealed any brain injury at all.

Toxic Torts, Brain Injury, Causation
Roberti ex rel. Roberti v. Andy’s Termite & Pest Control, Inc., 2011 WL 635369 (Cal.App.2d. 2011)
Plaintiff sued defendant Andy’s Termite and Pest Control, Inc., alleging that he suffered brain damage caused by in utero exposure to the pesticide chlorpyrifos (marketed as Dursban), which defendant applied at his home. The matter was tried by a jury and resulted in a defense verdict. Plaintiff now appeals from the judgment in favor of defendant, contending that the trial court committed evidentiary error with respect to expert testimony and cross-examination of those experts, in particular concerning causation between the toxic exposure and the brain defects. At trial, Plaintiff introduced expert testimony to prove that he suffers from “chronic static encephalopathy,” brain damage, cognitive impairment (IQ of 70-75, in the borderline retarded range), and learning disabilities due to in utero toxic exposure. Plaintiff’s experts performed a differential diagnosis to rule out all of the possible recognized causes of the condition other than Plaintiff’s in utero toxic exposure. Defense experts challenged the causal link between the toxin in the home and the Plaintiff’s injuries. Defense experts also testified that plaintiff does not suffer from brain damage, his CT scan appears normal, and he shows no sign of brain atrophy. The jury found in favor of the defense, finding that plaintiff’s harm was not the kind of harm that would be anticipated as a result of the risk created by pesticide application, that defendant did not fail to exercise extreme caution in selecting or applying chlorpyrifos in the subarea of plaintiff’s home, that the chlorpyrifos-containing Dursban performed as safely as an ordinary consumer would have expected, that Dursban’s design was not a substantial factor in causing harm to plaintiff, and that while Dursban had potential risks that were known or knowable in the scientific and medical community at the time of the application, the potential risks did not present a substantial danger to plaintiff. The appellate court affirmed the judgment and award of costs to the defendant.