Concepts, Methods, and Data Sources for Cumulative Health Risk Assessment of Multiple Chemicals, Exposures and Effects: A Resource Document (Final Report)
EPA announced the release of the final report, Concepts, Methods, and Data Sources for Cumulative Health Risk Assessment of Multiple Chemicals, Exposures and Effects: A Resource Document, in the June 27, 2008 Federal Register Notice.
This final report is a resource document that provides concepts, methods and data sources to assist in the conduct of multi-chemical, population-focused cumulative risk assessments. It is not guidance, but rather a presentation of information that could assist in the development of future guidance on cumulative risk assessment. It addresses a subset of issues related to chemical mixtures risk assessment that are identified in the 2003 Framework for Cumulative Risk Assessment. This report focuses on two areas:
- initiating factors for a cumulative risk assessment, with procedures for data collection and organization, and
- technical approaches for assessing human health risks associated with a multiple chemicals, exposures and effects.
- Procedures for population characterization, data collection and data organization based on the initiating factors for a cumulative risk assessment
- A chemical grouping method to scope analyses into manageable pieces to be assessed as multiple chemicals with co-occurring exposures and common toxicity
- Approaches and data sources for evaluating the timing of exposures, including discussions of chemical degradation over time in the environment and of kinetics and dynamics
- Integration of internal dose measurements to account for multiple route exposures
- Estimation of mixture risks for multiple route exposures by calculating route-specific risks using the Relative Potency Factor (RPF) approach and then summing the route-specific RPF-based risks across routes
- Integration of output from multiple effects modeling (illustrated using a categorical regression model) with the Hazard Index (HI) and response addition models to express risks for multiple health effects
- Detail on the cumulative HI approach, including impacts for risk characterization
- Refinement of the interaction-based HI method to account for toxicological interactions
- A method for cumulative risk characterization that considers factors unique to the conduct of a cumulative risk assessment, including uncertainties in cumulative dose-response and exposure assessment
- A general emphasis on integrating exposure and dose-response analysis
- A Risk Assessment Toolbox (Appendix A) that provides numerous sources of data and tools for use in conducting a cumulative risk assessment.
|Feb 2001||NCEA began work developing cumulative risk approaches and information through an Interagency Agreement with the Department of Energy.|
|May 2003||EPA's Risk Assessment Forum releases the 2003 Framework for Cumulative Risk Assessment.|
|Mar 2006||EPA releases the Considerations for Developing Alternative Health Risk Assessment Approaches for Addressing Multiple Chemicals, Exposures and Effect (External Review Draft) for public review and comment.|
|May 2006||EPA hosts an external peer review workshop for Considerations for Developing Alternative Health Risk Assessment Approaches for Addressing Multiple Chemicals, Exposures and Effect.|
|Jun 2008||EPA releases the final report.|
- (412 pp, 16 MB, about PDF)