State of the Science: Biologically Based Modeling in Risk Assessment [editorial]
The health risk assessment from exposure to a particular agent is preferred when the assessment is based on a relevant measure of internal dose (e.g., maximal concentration of an active metabolite in target tissue) rather than simply the administered dose or exposure concentration. To obtain such measurements, the relevant biology, physicochemical properties, and biochemical mechanisms of a specific agent are used to construct biologically-based models that can be used to predict its uptake, disposition, target tissue dose, and ensuing tissue responses in test animals and humans. The focus of this Special issue is the state of the science underlying the development and application of a specific type of biologically-based model [i.e., physiologically-based pharmacokinetic or (PBPK) models] in risk assessment. The fourteen papers presented herein address critical issues and advances relating to their use in current risk assessment approaches with a focus on their use in emerging toxicology paradigms as well.