The document is the first in a series of volumes developed for the U.S. Environmental Protection Agency, Office of Toxic Substances to assist in the assessment of exposure to chemical substances. This introductory volume discusses issues of general interest in all exposure assessments, including a discussion on planning an assessment, and summarizes the contents of the next eight volumes. Planning an exposure assessment is a function of the purpose, scope, depth, and approach of the assessment. The report presents a list of questions that, when answered, aid the assessor in determining the resources and tools needed to do the assessment. The organization of an exposure assessment is discussed, and a basic outline that can be used is provided. The content of major sections in an exposure assessment are discussed: General Information, Sources, Exposure Pathways and Environmental Fate, Monitoring or Estimated Concentrations, Exposed Populations, and the Integrated Exposure Analysis. An overview of exposure assessments in different settings is presented. Different types of assessments (screening level, intermediate level, detailed, and special assessments) are described.

Project Officer: Michael A. Callahan. Vesar, Inc. Contract Number: 68-02-3968 "July 1985." "EPA 560/5-85-001." "Exposure Evaluation Division, Office of Toxic Substances, Washington, D.C. 20460."