ABSTRACT
Extrapolation is an integral part of the process of setting environmental quality criteria and for conducting environmental risk assessments for substances. Extrapolation is used routinely in many jurisdictions and for many purposes, ranging from those required in regulatory acts and instruments to those conducted for managerial and economic decision making. Problem formulation is an integral component of all frameworks for criteria setting and risk assessment and is critical to success as it lays down the foundation upon which the process depends. Extrapolations always have been a key component of criteria setting and risk assessment, either formally or informally. Extrapolation used to infer toxicity from one type of exposure regimen to another is often termed “temporal extrapolation.” The extrapolation of laboratory single-species responses to the population level is another ecologically relevant extrapolation that is routinely conducted without extensive confirmation of its appropriateness. The chapter also presents an overview of the key concepts discussed in this book.
