1.23 – Risk Assessment☆

The ultimate motivation for the field of toxicology is to provide insight into the potential for substances to adversely affect human health in exposed individuals. As the science of toxicology has expanded and developed, gaining ever deeper insights into the modes and mechanisms of interaction of chemicals with the living organism, its intellectual focus has moved beyond merely treating toxicity as a phenomenon to be observed. Toxicologists have sought to understand the nature of chemical toxicity and the ultimate causal processes that underlie disturbance of function and damage to cells and tissues. The boundaries between toxicology per se and its related fields of physiology, pharmacology, molecular, and cellular biology have become less distinct as the knowledge and tools of these allied disciplines are brought to bear. As the other chapters in the present volume and the other volumes in this series demonstrate, modern toxicology has evolved beyond simple “toxicity testing” (i.e., documentation of frank toxicity following the administration of fixed doses of a test substance in standardized experiments). Today, toxicology is a multifaceted system of scientific inquiry into fundamental biological processes.