Opinion ID: 772445
Heading Depth: 4
Heading Rank: 3

Heading: Dr. Hirsch's Testimony

Text: 34 Hirsch, board certified in neurology and psychiatry, examined the seven flagship plaintiffs and testified that their various conditions were more likely than not caused by exposure to PCBs. He concluded that of the seven flagship plaintiffs, all suffered from encephalopathy, four from polyneuropathy, three from cephalgia (headaches), one from hyposmia (reduced ability to smell), two from hypogeusia (reduced ability to taste), one from optic neuropathy, one from autonomic neuropathy, and one from phantosmia (hallucinating a smell). The magistrate found, over defendant's objections, that Hirsch was qualified as an expert, but excluded his testimony because his opinion that these conditions were caused by exposure to PCBs from Station 79 was not based on valid scientific knowledge. 35 Plaintiffs emphasize that the standardized diagnostic tests used by Hirsch are generally accepted methods for detecting neurological impairments. The acceptance of those tests, however, does not demonstrate the scientific validity and reliability of his opinion that the deficits he observed were caused by exposure to PCBs. It is the methodology by which he reached his opinion concerning causation that must be found reliable. Hirsch admitted no knowledge concerning the actual exposure of the seven plaintiffs to PCBs or the temporal relationship between their exposure and symptoms. The magistrate judge properly rejected the circular reasoning that the plaintiffs must have been exposed to the PCBs because PCBs were present in the environment and plaintiffs showed symptoms. 36 In addition, the magistrate found that Hirsch failed to account for confounding factors, or identify scientific literature that supported his theory that the symptoms at issue can be caused by exposure to PCBs. Although plaintiffs repeatedly state that Hirsch referred to a list of 120 scientific articles, they fail to identify any specific literature that supports his conclusion with respect to causation. Our review of the record convinces us that the magistrate judge did not abuse his discretion by finding that Hirsch's testimony was not based upon valid scientific knowledge and would not assist the trier of fact. 37 AFFIRMED.