Grantee Research Project Results

2008 Progress Report: Impact of Emission Reductions on Exposures and Exposure Distributions: Application of a Geographic Exposure Model

EPA Grant Number: R833624
Title: Impact of Emission Reductions on Exposures and Exposure Distributions: Application of a Geographic Exposure Model
Investigators: Marshall, Julian D. , Ramachandran, Gurumurthy
Institution: University of Minnesota School of Public Health
EPA Project Officer: Hahn, Intaek
Project Period: September 1, 2007 through October 31, 2010 (Extended to February 29, 2012)
Project Period Covered by this Report: September 1, 2007 through October 31,2008
Project Amount: $459,556
RFA: Development of Environmental Health Outcome Indicators (2006) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics , Air

Objective:

The objective of this project is to quantify source-to-receptor relationships and evaluate potential emission reductions strategies.

Progress Summary:

Research efforts to date have involved training a new student (Ms. Katie Lundquist) to run the necessary models, and updating and automating those models (the CAMx air dispersion model and the University of Minnesota mobility-based exposure model).

The exposure model has been updated to run with the current version of Visual Studio and code written for post-processing model output. A major component of this study is evaluating emissions reductions strategies in terms of environmental equity. To this end, a system to quantify various environmental equity metrics and compare model results has been developed.

Ms. Lundquist spent 1 week at ENVIRON International Corporation (Novato, California) in an intensive training session on CAMx. Previous research used emissions inventories from the 2001 Multiple Air Toxics Exposure Study II (MATES II) study. We have updated our inputs to reflect changes found in the 2007 MATES III study.

Using the MATES III study and the mobility-based exposure model, Ms. Lundquist determined base-case exposure levels to fine diesel particulate matter and compared results with a 1 ton per week emissions reduction to the following sources: on-road mobile sources, off-road mobile sources, ships, trains and stationary sources. We compared intake rates among sources for participants in the travel-activity diary. Additionally, we quantified environmental justice using the Gini coefficient, Atkinson coefficient, and relative difference between high- and low-socioeconomic status groups.

Results can be plotted on a graph with reductions in mean exposure level along the x-axis and reductions in environmental injustice along the y-axis to provide a visual comparison of various emission-reduction strategies. In this case, the optimum solutions would have high x and y values. Results showed that reductions to ship and train emissions would have the maximum exposure and environmental justice benefit as compared to on-road, off-road or stationary sources. However, the framing of the reduction benefit is important. More research will be done to compare methods of determining benefit to explore the sensitivity of these calculations and discern the most appropriate way to represent results.

Future Activities:

Future activities will include incorporating the cost of reducing pollution from each of the five diesel particulate matter sources into the results. We also will repeat the process with other pollutants as well as analyze the spatial and temporal signatures.

Journal Articles on this Report : 1 Displayed | Download in RIS Format

Publications Views
Other project views:	All 15 publications	6 publications in selected types	All 6 journal articles

Publications
Type	Citation	Project	Document Sources
Journal Article	Marshall JD. Environmental inequality:air pollution exposures in California's South Coast Air Basin. Atmospheric Environment 2008;42(21):5499-5503.	R833624 (2008) R833624 (2009) R833624 (2011) R833624 (Final)	Full-text: ScienceDirect - Full Text PDF Exit Abstract: ScienceDirect - Abstract & Full Text HTML Exit Other: ResearchGate - Abstract & Full Text PDF Exit

Supplemental Keywords:

Exposure, air pollution, sensitive subpopulations, decision making, California, South Coast Air Basin, environmental justice, intake fraction, CAMx air dispersion model;

Progress and Final Reports:

Original Abstract

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.