Structural and functional considerations in the definition of toxicity

This symposium offers insights into selected current state of affairs regarding the difficulties encountered in toxicity evaluation studies when examining tissues and determining significance of toxicity. As our ability to detect structural and functional deviations from normal increases, the definitions of toxicity become more complicated. Both toxicologists and pathologists must work together in a cooperative manner to further elucidate the questions raised by the papers in this symposium. It is a conceptual and intellectual challenge which must be met if safety assessment advances are to be made (Ruben and Rousseaux, 1989).