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Cumulative Risk Research
Addressing Cumulative Risk
The Human Health Research Program is developing and demonstrating the processes, tools, and data needed to understand how we are affected by the chemical mixtures that we are exposed to in our daily lives. Cumulative risk research supports EPA's efforts to conduct cumulative risk assessments that consider chemical exposures from multiple sources. Chemicals may travel from their sources to people by multiple pathways and may be taken into the body through multiple routes, including inhalation, ingestion, or uptake through the skin. A further complication is that chemicals in a mixture may interact with one another to produce effects different or more severe than they would alone. Alternatively, exposure to a mixture of chemicals or to a single chemical by multiple routes may produce an effect greater than would be predicted by simply adding the individual effects together-what could be termed a "synergistic" or "1 + 1 = 3" effect.
EPA scientists are studying how people are exposed to environmental contaminants; the magnitude and timing of these exposures; how exposures translate into tissue dose and relate to potential health effects; how biomarker of exposure results can be used by risk assessors and how exposure biomonitoring results can be used to demonstrate that the Agency's policies and regulatory actions have resulted in improved human health.
Goals
- Provide data from chemical classes that will directly support ongoing risk assessment decisions by EPA, including carbamate and pyrethroid pesticides
- Develop and implement dose-time-response models for calculating the relative potencies of N-methyl carbamate pesticides and develop models to assess cumulative risk of N-methyl carbamate exposure
- Address issues of extrapolating mixture data across dosing scenarios, dose levels, methodologies, and populations
- Enable an understanding of the influence of dose and mixture composition on the joint toxic action of mixtures
- Develop predictive models that will link in vitro, pharmacokinetic and in vivo pharmacodynamic components