Secondary and Regional Contributions to Organic PM: A Mechanistic Investigation of Organic PM in the Eastern and Southern United States

EPA Grant Number: R831073
Title: Secondary and Regional Contributions to Organic PM: A Mechanistic Investigation of Organic PM in the Eastern and Southern United States
Investigators: Turpin, Barbara , Lim, Ho-Jin , Seitzinger, Sybil
Institution: Rutgers, The State University of New Jersey
EPA Project Officer: Chung, Serena
Project Period: September 1, 2003 through August 31, 2006 (Extended to August 31, 2007)
Project Amount: $446,061
RFA: Measurement, Modeling, and Analysis Methods for Airborne Carbonaceous Fine Particulate Matter (PM2.5) (2003) RFA Text |  Recipients Lists
Research Category: Air , Air Quality and Air Toxics , Particulate Matter


Atmospheric (secondary) formation and regional transport are responsible for a large portion of PM2.5 mass in the eastern United States, even in urban areas. In addition, there is growing evidence suggesting that, as for sulfate, organic PM can be formed not only by homogeneous gas phase reactions, but also by heterogeneous (including aqueous-phase) reactions. We hypothesize that atmospheric chemistry and transport models underestimate secondary OC and the regional contribution to OC in the eastern and southern United States because substantial organic PM is formed through heterogeneous processes (i.e., cloud processing) during regional transport. We propose to provide a better understanding of fundamental atmospheric (i.e. aqueous/heterogeneous) processes needed to predict organic (OC) particulate matter (PM) concentration, organic species composition, and effects from emissions of particles and precursor species (i.e. improve predictive models). Further, we will examine evidence indicating the importance of these secondary processes in the eastern US using Supersite data and samples. We expect that this initial work will lead to the identification of secondary 'source tracers' or 'process indicators' that can be used in data analysis efforts and receptor modeling to identify the importance of primary vs. secondary, local vs. transport, and/or homogeneous vs. heterogeneous processes. Additionally, this work will improve predictive models and therefore lead to the development of more effective air pollution control strategies.


The specific aims are:

  1. Conduct controlled laboratory experiments investigating the secondary formation of organic particulate matter through cloud/fog processing.
  2. Analyze samples from the Pittsburgh Supersite for products identified in #1, and examine eastern Supersite data for evidence of heterogeneous formation and to identify conditions conducive to secondary formation through cloud processing.
  3. Examine the suitability of tracers/process indicators suggested above for estimation of primary vs. secondary, local vs. regional and/or heterogeneous vs. homogeneous contributions to ambient organic PM.
  4. Expected Results:

    This work will provide a better understanding of the contribution of regional transport and secondary formation to ambient organic PM concentrations. It will provide critical scientific knowledge that is needed to accurately predict PM2.5 concentrations and identify effective air quality management strategies. This, and other research of this type, enables air quality management decisions that maximize public health protection and minimize cost.

    Publications and Presentations:

    Publications have been submitted on this project: View all 32 publications for this project

    Journal Articles:

    Journal Articles have been submitted on this project: View all 9 journal articles for this project

    Supplemental Keywords:

    secondary aerosol, carbonaceous PM2.5, PM sources,, RFA, Scientific Discipline, Air, Ecosystem Protection/Environmental Exposure & Risk, particulate matter, Air Quality, air toxics, Environmental Chemistry, Air Pollution Effects, Monitoring/Modeling, Analytical Chemistry, Environmental Monitoring, Engineering, Chemistry, & Physics, Environmental Engineering, air quality modeling, health effects, organic pollutants, particle size, carbon aerosols, atmospheric dispersion models, particulate organic carbon, atmospheric particulate matter, chemical characteristics, PM 2.5, atmospheric particles, aerosol particles, air quality models, air modeling, airborne particulate matter, emissions, air sampling, carbon particles, air quality model, ultrafine particulate matter, particulate matter mass, modeling studies, transport modeling, aerosol analyzers, atmospheric chemistry, chemical speciation sampling, measurement methods, particle dispersion

    Progress and Final Reports:

  5. 2004 Progress Report
  6. 2005 Progress Report
  7. 2006 Progress Report
  8. Final Report