Human Exposure and Atmospheric Sciences

Summary

Historically, risk assessments have often focused on exposure to one pollutant via one exposure pathway (e.g., inhalation). In reality, people are exposure to a mixture of pollutants through multiple pathways (inhalation, ingestion, dermal adsorption). The goal of this research is to improve our understanding of aggregate exposures (exposure to a single pollutant via multiple pathways) and cumulative exposures (aggregate exposure from multiple pollutants). To accomplish this goal, EPA is developing and applying cumulative exposure and dose models and developing approaches to interpret biomarkers of exposure. In addition, EPA  is developing additional methods and modeling tools to characterize cumulative risks from environmental contaminants in communities.

Research Areas

Source to Dose Modeling - EPA’s Human Exposure and Atmospheric Science researchers  produce documented, user-friendly, reliable state-of-the-science aggregate exposure and dose models that may be used within EPA or by external customers to improve estimates of human exposure and dose, and provide a better understanding of aggregate exposures and cumulative risks. Predictive models are developed and refined to reduce uncertainties in describing physical, chemical, and biological processes that lead to exposure and dose of chemical contaminants. This research improves the scientific basis of the risk assessment and risk management process by estimating distributions of aggregate exposures and doses for a variety of multi-media, multi-pathway pollutants. Details of Source to Dose Modeling

Interpretation and Use of Biomarkers - Biomarkers can be powerful tools for assessing aggregate and cumulative exposures to environmental pollutants. However, there are considerable uncertainties in how to best use and interpret biomarkers for assessing environmental concentrations and exposures. EPA’s Human Exposure and Atmospheric Science researchers  use methods development, measurements, and modeling tools to assess relationships between biomarkers, exposure/environmental concentrations, and dose. This research provides guidance on how to generate meaningful biomonitoring data in future studies and how to interpret biomarker data produced in ongoing surveys. Details of Interpretation and Use of Biomarkers

Community-Based Cumulative Risk - Communities are often faced with risks from cumulative exposures to various environmental sources and other non-chemical stressors.  Understanding and prioritizing these risks is important to develop effective mitigation strategies to protect public health.  EPA Human Exposure and Atmospheric Science researchers conduct research to develop, evaluate, and apply tools for estimating exposures to multiple stressors that will lead to cumulative risks, specifically targeted toward understanding the key elements that lead to groups of individuals and/or community-level exposures and risks.  This research is conducted in collaboration with EPA Regions, other federal agencies, state, local,  and tribal organizations, and academic partners. Details of Community-Based Cumulative Risk