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DEVELOPMENT OF A MICROSCALE EMISSION FACTOR MODEL FOR PARTICULATE MATTER (MICROFACPM) FOR PREDICTING REAL-TIME MOTOR VEHICLE EMISSIONS

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http://cfpub.epa.gov/si/si_public_comments.cfm

Citation:

Singh, R. B., A H. Huber, AND J N. Braddock. DEVELOPMENT OF A MICROSCALE EMISSION FACTOR MODEL FOR PARTICULATE MATTER (MICROFACPM) FOR PREDICTING REAL-TIME MOTOR VEHICLE EMISSIONS. JOURNAL OF AIR & WASTE MANAGEMENT ASSOCIATION 53(10):1204-1217, (2003).

Impact/Purpose:

The research is planned to meet the following objectives:

Support is provided to HEASD Tasks by Alan Huber. (60% 9524 New Air Toxics Modeling, ; 10% 5732 PM Population Exposure Modeling; 10% 3948 Next Generation MMMP Exposure Modeling; 10% N533 PM Toxic agent exposure modeling, and 10% 3957 Integrated Human Exposure Source-to-Dose Modeling)

  • Development of data and algorithms for exposure modeling in urban areas, to be used in refined probabilistic exposure models being developed elsewhere, to allow prediction of human exposures for an urban population.

  • Characterize exposures and variability of concentrations in critical microenvironments in urban areas using targeted measurement studies and refined air quality models.

  • Identify critical human activities influencing exposures, especially identifying microenvironments that are key to exposures to urban air toxics.

  • Develop methods (measurements, dispersion modeling, receptor modeling) to distinguish exposures to "near field" sources - like indoor sources, human activities or hobbies, or nearby point or area sources - from "background" concentrations or from distant sources that can be modeled well by compartmental or air quality models.

  • Provide data and algorithms based on a scientific understanding of exposure dynamics for inclusion in NERL human exposure models and other models like OAR's TRIM..

    • Description:

    The United States Environmental Protection Agency's National Exposure Research Laboratory is pursuing a project to improve the methodology for modeling human exposure to motor vehicle emissions. The overall project is to develop improved methods for modeling the source through the air pathway to human exposure in significant microenvironments of exposure. Current particulate matter (PM) emission models, PART (used in the United States, except California) and EMFAC (used in California only), are suitable only for regional (county) scale modeling and emission inventories because of their dependence on aggregated vehicle-miles-traveled data. These emission models are not designed to estimate real-time emissions needed for human exposure studies near roadways. There is a need to develop site-specific real-time emission factor models for PM emissions.

    A microscale emission factor model for predicting site-specific real-time motor vehicle PM(MicroFacPM) emissions for TSP (total suspended particulate matter), PM (MicroFacPM) emissions for total suspended PM, PM less than 10 m aerodynamic diameter, and PM less than 2.5 m aerodynamic diameter has been developed. The algorithm used to calculate emission factors in MicroFacPM is disaggregated, and emission factors are calculated from a real-time fleet, rather than from a fleet-wide average estimated by a vehicle-miles-traveled weighting of the emission factors for different vehicle classes. MicroFacPM requires input information necessary to characterize the site-specific real-time fleet being modeled. Other variables required include average vehicle speed, time and day of the year, ambient temperature, and relative humidity.

    EPA, through its Office of Research and Development, funded the research described here. This paper has been subjected to agency review and approved for publication.

    Record Details:

    Record Type:DOCUMENT( JOURNAL/ PEER REVIEWED JOURNAL)
    Product Published Date:10/01/2003
    Record Last Revised:07/25/2008
    OMB Category:Other
    Record ID: 75831