Toxic tort litigation: medical and scientific principles in causation.

A definition and an explanation of the legal standard for imposition of legal liability in a toxic tort case are set forth. The focus is on how expert witnesses utilize the applicable medical and scientific data in order to provide opinion evidence of the causal relation between exposure to a toxic substance and disease in an individual case. The author concludes that policy considerations are present in both the legal standard and the basis for establishing a cause and effect relation.