3 - Risk analysis and toxic substances

Abstract

Risk analysis should be viewed as a much wider concept than risk assessment. Risk assessment is the characterization of the potential adverse health effects of human exposure to a chemical hazard, which involves the characterization of the uncertainties inherent in the process of inferring risk. It is the process aimed at describing and quantifying the risk(s) associated with exposure to a toxic substance, taking into account data obtained in animals, and possibly in man, the evidence for a dose–effect relationship and/or a threshold dose, and finally data regarding the presumed or actual human exposure. Thus, risk assessment is often classified into four major components: hazard (or toxicity) identification, dose–response evaluation, exposure assessment, and risk characterization. This chapter is an attempt to define current concepts in risk analysis and to draw a general framework for those toxicologists who are more specifically committed to issues of toxicity in human beings and their societal consequences.