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Characterizing climate change impacts on human exposures to air pollutants
Citation:
Dionisio, K., Chris Nolte, T. Spero, AND K. Isaacs. Characterizing climate change impacts on human exposures to air pollutants. ISES Annual Meeting, Henderson, NV, Henderson, NV, October 18 - 23, 2015.
Impact/Purpose:
The National Exposure Research Laboratory (NERL) Human Exposure and Atmospheric Sciences Division (HEASD) conducts research in support of EPA mission to protect human health and the environment. HEASD research program supports Goal 1 (Clean Air) and Goal 4 (Healthy People) of EPA strategic plan. More specifically, our division conducts research to characterize the movement of pollutants from the source to contact with humans. Our multidisciplinary research program produces Methods, Measurements, and Models to identify relationships between and characterize processes that link source emissions, environmental concentrations, human exposures, and target-tissue dose. The impact of these tools is improved regulatory programs and policies for EPA.
Description:
Human exposures to air pollutants such as ozone (O3) have the potential to be altered by changes in climate through multiple factors that drive population exposures, including: ambient pollutant concentrations, human activity patterns, population sizes and distributions, and housing stocks. An integrated methodology for modeling changes in human exposures due to these impacts was developed by linking climate, air quality, landuse, and human exposure models, and was applied to characterize changes in predicted human exposures to O3 for a current climate scenario versus multiple future scenarios. Regional climate projections for the U.S. were developed by downscaling global circulation model (GCM) scenarios for three Representative Concentration Pathways (RCPs) using the Weather Research and Forecasting (WRF) model. The regional climate results were in turn used to generate air quality (concentration) projections for O3 and PM using the Community Multiscale Air Quality (CMAQ) model. Future U.S. census-tract level population distributions from the Integrated Climate and Land Use Scenarios (ICLUS) model for four future scenarios based on the Intergovernmental Panel on Climate Change’s (IPCC) Special Report on Emissions Scenarios (SRES) storylines were used. These climate, air quality, and population projections were used as inputs to EPA’s Air Pollutants Exposure (APEX) model for 12 U.S. cities. Initial results show that future climate scenarios may have a greater impact on high level O3 exposures than future population scenarios. Different future climate scenarios result in a ~7% increase in the number of people (a ~9% increase in the number of children ages 5-18) with at least 1 daily maximum 8 hour exposure above 60 ppb in Los Angeles. This integrated system can be used to quantify 1) the relative contribution of multiple climate-based factors on human exposure changes and 2) the variability in human exposure changes across multiple climate change scenarios.
