Daubert rulings in toxic tort case

The Court reviewed several Daubert rulings in the toxic tort case of Johnson v. Arkema, Inc., No. 11-50193 (June 20, 2012).  Under an abuse-of-discretion standard, it affirmed the exclusion of experts based on weaknesses in reliance upon (1) analysis of whether the materials at issue belonged to a “class of chemicals” known to cause disease; (2) state and federal exposure guidelines; (3) animal studies; and (4) the “temporal connection” between exposure and illness.  Op. at at 8-20.  The Court then affirmed the exclusion of an opinion based on a “differential diagnosis,” concluding that it was based on an unreliable presumption about general causation.  Id. at 22.  The Court concluded by reversing on a causation issue that did not require expert testimony, finding that the temporal connection between exposure and certain chronic injuries was close enough to allow trial — while also finding that the connection was to attenuated as to related chronic injuries.  Id. at 26.  A dissent took issue with the majority’s reasoning as to one well-credentialed toxicology expert.  Id. at 29.