ABSTRACT
A major tenet of toxicology holds that the “dose” of a contaminant determines the compound’s toxicity. However, it is not actually the dose that is important but the concentration of the compound at the site of action. As Rozman and Klaassen (1996) state, “the concentration of the compound at the site of action is proportional to the dose, but the same dose of two or more chemicals may lead to vastly different concentrations in a particular target organ of toxicity.” This concept particularly deserves attention in the study of endocrine-disrupting contaminants, given the numerous studies recently showing an apparent lack of dose-response behavior of chemicals. This chapter will review the major factors affecting the concentration of endocrine-altering contaminants at the site of action: namely, bioaccumulation, storage, and mobilization of compounds.
