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Cumulative Risks
Cumulative risk assessment is broadly defined as "the combined risks from aggregate exposures to multiple agents or stressors." Humans are exposed to mixtures of chemicals from multiple sources via multiple pathways and routes. The combined risk from everyday, real-world exposures may be equal to, greater than, or less than what might be predicted from combining risk data on individual chemicals from single routes of exposure. Advances in science and the need for a more complete understanding of risk have prompted a research focus on cumulative risk assessment. Four key scientific questions, resolution of which will significantly improve future cumulative risk assessments, were identified in the development of the HHRP based upon discussions with scientists and risk assessors from EPA regulatory program offices, EPA regional offices, and other human health researchers. NERL research addresses three of these questions:
- How can biomarkers be used in cumulative risk assessment?
- What source-to-dose models are needed for cumulative risk?
- How can cumulative risk at the community level be evaluated?