PM is one of the air quality criteria pollutants outlined in the Clean Air Act that are generated, in part, by motor vehicles. PM has gained interest since it is a significant pollutant coming from diesel vehicles which are critical to both the transit and transportation freight industries. Another distinction between PM and the other criteria pollutants is that one form of PM, (DPM), has been identified as a probable carcinogen and listed as an "air toxic" compound by EPA.
The FHWA has undertaken a PM Research Program to determine the contribution of mobile sources to PM emissions and to quantify this relationship as accurately as possible. This is important since areas designated as nonattainment must develop plans for reducing their emissions.
PM is unique in that it has two different standards. There is a "coarse" standard which regulates PM particles 10 µm in size or smaller and referred to as PM10. These particles are typically formed by "crustal" or earth-based material and enter the air through a variety of actions including "entrainment" into the atmosphere by wind blown dust. Particles from brake and tire wear, from pavement wear, and from other vehicle degenerative processes also contribute to this PM size. The greatest contribution from this size category has "natural" rather than "man-made" origins.
The other size of concern, and the most recent addition to the criteria standards, is for "fine" PM material referred to as PM2.5 (2.5µm or smaller). These particles are thought to be more a product of combustion sources. This material is believed to penetrate deeper into the lungs and remain lodged there rather than exhaled, causing negative impacts on health.
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This Strategic Plan for Particulate Matter Research (Strategic Plan) identifies priority particulate matter (PM) research issues for the transportation community for the years 2005 through 2010. It updates and expands on a previous Federal Highway Administration (FHWA) strategic plan for PM research covering the 2000 through 2004 time period (Carr et al., 2002a). This Strategic Plan identifies areas of research that have the greatest potential to yield insights directly applicable to state Departments of Transportation (DOTs) and regional Metropolitan Planning Organizations (MPOs) charged with developing and implementing transportation plans, programs, and projects. The timeframe for this Strategic Plan extends to 2010 to correspond with PM2.5 attainment planning and the timeframe used by the National Research Council (NRC) for its long-range PM research portfolio (National Research Council, 1998).
This strategy document outlines major research covering five topic areas that the US transportation community needs to address. This document was developed by a panel of PM experts from Federal, State, and local governments, from academia, consultants, and from organizations supporting PM issues based on their analysis of a literature review of research conducted on mobile source generated PM.
FHWA PM10 Qualitative Analysis Conformity Guidance, September 12, 2001
This document provides information on how to conduct a qualitative analysis on projects for their likely impacts on PM emissions.
Particulate Matter Guidance Document
Abstract: This paper was developed to advise field staff and others involved in particulate matter (PM-10) issues on the state of the knowledge in this area. It discusses the PM standard, PM sources, and the classification of geographic areas into attainment and nonattainment areas. Some general information is discussed about modeling using the PART5 emission factor model. Conformity issues, SIPs requirements, and further revisions of the PM-10 NAAQS are also discussed.
Author: Jay Turner, Publication Year: 1995
Contact: The Office of Natural and Human Environment at environment@fhwa.dot.gov.
