Contribution of Primary and Secondary PM Sources to Exposure & Evaluation of Their Relative Toxicity

EPA Grant Number: R832413C001
Subproject: this is subproject number 001 , established and managed by the Center Director under grant R832413
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: Southern California Particle Center
Center Director: Froines, John R.
Title: Contribution of Primary and Secondary PM Sources to Exposure & Evaluation of Their Relative Toxicity
Investigators: Sioutas, Constantinos , Hinds, William C. , Schauer, James J. , Shafer, Martin M. , Fine, Philip M. , Geller, Michael , Zhu, Yifang
Institution: University of Southern California , University of California - Los Angeles , University of Wisconsin
EPA Project Officer: Chung, Serena
Project Period: October 1, 2005 through September 30, 2010 (Extended to September 30, 2012)
RFA: Particulate Matter Research Centers (2004) RFA Text |  Recipients Lists
Research Category: Health Effects , Air


The primary objective of Project 1 is to examine the relationships between PM sources, exposure, and toxicity within the constraints of the urban atmosphere. This project is an integral part of Projects 2, 3 and 4, by serving as the field operations to collect PM samples for toxicity testing and for providing elevated levels of ambient PM for animal exposure models described in these projects.


State-of-the-art portable particle concentrator technologies, deployed and refined over the previous five years of the Center, allow for concentration and collection of ambient PM at multiple sites throughout the Los Angeles Basin. These sites will be purposely chosen to reflect areas impacted by the different major outdoor and indoor sources in Southern California. As will be discussed later, most of the study locations will also be sampling sites that have served the USC Childrens Health Study (CHS), providing continued linkage to that study. Advanced chemical analysis and source apportionment techniques will provide a quantitative characterization of the PM as well as the source contributions at each sampling site. In addition, state-of-the-art technologies will provide a method to measure the toxicity of PM components, including chemistry and volatility. The central hypothesis of Project 1 is that particle characteristics, which can be related to sources in terms of size and composition, determine the toxicology of PM, and variations in exposure to these characteristics according to source, season, and location influence the eventual human health response. The project consists of the following specific aims:

  1. To determine the physical and chemical properties of atmospherically processed PM emissions from real-world sources, including secondary formation, to evaluate how exposure to PM and the toxicity of PM from these sources vary with respect to location, season, and particle size, and in conjunction with Projects 2, 3 and 4 to assess their relative toxicity.
  2. To assess the contributions of these outdoor sources to indoor exposure and toxicity.
  3. To determine the physical, chemical and toxicological characteristics of the volatile and non-volatile particle components that originate from mobile sources.
  4. To measure the exposure gradients and intra-community variability of PM in complex urban areas, affected by a multitude of sources, including unstudied sources such as airports and port activities.

Expected Results:

This project will provide valuable insight into the source-exposure-response continuum outlined by the National Research Council (NRC, 2004) by developing fundamental understanding on the links between specific sources and adverse toxicological outcomes associated with exposure to PM. The information generated by this project will serve as the basis for linking emissions to local air quality and ultimately to health effects. By providing a wide range of exposure parameters for the toxicological studies described in Projects 2, 3 and 4, the toxicity of different sources and exposure scenarios can be assessed. Knowing the relative toxicity of atmospherically processed PM emissions from real-world sources will allow for more targeted and effective regulatory strategies. These data on which PM sources are the most toxic, combined with detailed chemical and physical characterization of PM from these sources will allow for a narrower, more focused effort in identifying the biological mechanisms of PM health effects (as described in Projects 2, 3 and 4).

Publications and Presentations:

Publications have been submitted on this subproject: View all 87 publications for this subprojectView all 241 publications for this center

Journal Articles:

Journal Articles have been submitted on this subproject: View all 85 journal articles for this subprojectView all 157 journal articles for this center

Supplemental Keywords:

PM, sources, toxicity, apportionment, ultrafine, semi-volatile,, RFA, Health, Scientific Discipline, Air, particulate matter, Health Risk Assessment, Risk Assessments, Biochemistry, Ecology and Ecosystems, particulates, atmospheric particulate matter, chemical characteristics, human health effects, PM 2.5, toxicology, airway disease, cardiovascular vulnerability, airborne particulate matter, air pollution, human exposure, vascular dysfunction, cardiovascular disease, human health risk

Progress and Final Reports:

  • 2006 Progress Report
  • 2007 Progress Report
  • 2008 Progress Report
  • 2009 Progress Report
  • 2010 Progress Report
  • 2011
  • Final Report

  • Main Center Abstract and Reports:

    R832413    Southern California Particle Center

    Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
    R832413C001 Contribution of Primary and Secondary PM Sources to Exposure & Evaluation of Their Relative Toxicity
    R832413C002 Project 2: The Role of Oxidative Stress in PM-induced Adverse Health Effects
    R832413C003 The Chemical Properties of PM and their Toxicological Implications
    R832413C004 Oxidative Stress Responses to PM Exposure in Elderly Individuals With Coronary Heart Disease
    R832413C005 Ultrafine Particles on and Near Freeways