Considerations for Developing Alternative Health Risk Assessment Approaches for Addressing Multiple Chemicals, Exposures and Effect (External Review Draft)
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This report is not guidance but rather a presentation of concepts that could assist the development of guidance. It presents risk assessment approaches and information on a subset of issues that are identified in the 2003 Framework for Cumulative Risk Assessment. The sequence of procedural steps suggested in this report is designed to emphasize the links between the exposed population and the multiple factors being addressed. The audience for this report is anyone involved in chemical risk assessment who needs to address the joint impact of multiple chemicals, exposures and effects.
Existing EPA guidance addresses some of the aspects of cumulative risk, but none addresses all of the combinations of multiples included in this report, such as consideration of the composite impact of multiple health effects. Among the distinctive new approaches are:
- grouping chemicals based on exposure characteristics and toxic endpoints for use in applying chemical mixtures risk assessment methods,
- assessing multi-route exposure combinations using relative potency factors,
- integration of categorical regression modeling of multiple effects with additivity approaches, and
- emphasis on the iteration and collaboration between exposure assessment and dose-response assessment to ensure compatible and relevant information.
- Areas of cumulative health risk assessment emphasized in this report can often be performed with existing information.
- Exposure and toxicity characterizations of mixtures are strongly dependent on mixture composition (chemicals and concentrations) and timing of exposures and health effects.
- Qualitative and semiquantitative approaches provided can simplify the number of potential combinations of chemicals, exposures, and effects to make the cumulative health risk assessment more feasible.
|Feb 2001||NCEA began work developing cumulative risk approaches and information through an Interagency Agreement with the Department of Energy.|
|May 2003||EPA releases the 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.|
This download(s) is distributed solely for the purpose of pre-dissemination peer review under applicable information quality guidelines. It has not been formally disseminated by EPA. It does not represent and should not be construed to represent any Agency determination or policy.