Cover title. "EPA/600/R-06/013F." "August 2007." Includes bibliographical references.

Cumulative risk assessment introduction -- Background -- About this report -- Existing EPA publications related to cumulative risk -- This report's approach to cumulative risk assessment -- Identification of initiating factors, population characteristics, data collection and organization -- Initiating factors for cumulative risk -- Initial description of the population -- Initial assessment of exposure data -- Integration of public health information -- Epidemiologic investigations in cumulative risk assessment -- Linking the list of relevant chemicals to the population profile through a conceptual model -- Exposure assessment of multiple chemicals, exposures and effects -- Defining exposure assessment for cumulative risk assessments that evaluate multiple chemical exposures -- U.S. EPA exposure assessment guidance -- Cumulative exposure assessment: analysis phase -- Illustration of cumulative concepts for the air pathway at a contaminated site -- Retrospective studies -- Summary comparison and screening suggestions -- Toxicity assessment of multiple chemicals, exposures and effects -- Defining cumulative toxicity assessment -- Toxicity assessment guidance and methods -- Toxicology of internal co-occurrence -- Chemical mixtures grouping and toxicity assessment scheme -- Evaluating multiple effects -- Evaluating interaction effects -- Evaluating multiple route exposures -- Summary recommendations -- Cumulative risk characterization -- Characterization of risk in a cumulative risk assessment context: an overview -- Special concerns with cumulative risk characterization -- Risk characterization process for cumulative risk assessment -- Variability and uncertainty in exposure and dose-response -- Example evaluations of quantitative approaches to cumulative risk characterization -- Outcomes form cumulative risk characterization-- Summary -- Glossary -- Appendix A: Cumulative risk toolbox -- Appendix B: Toxicity information to support groupings -- Appendix C: Severity of toxic effect.