2002 Progress Report: Physical and Chemical Characteristics of PM in the LAB (Source Receptor Study)

EPA Grant Number: R827352C014
Subproject: this is subproject number 014 , established and managed by the Center Director under grant R827352
(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: Physical and Chemical Characteristics of PM in the LAB (Source Receptor Study)
Investigators: Sioutas, Constantinos , Cho, Arthur K. , Froines, John R. , Harkema, Jack , Hinds, William C. , Kleinman, Michael T. , Miguel, Antonio
Current Investigators: Sioutas, Constantinos
Institution: University of Southern California , Michigan State University , University of California - Irvine , University of California - Los Angeles
Current Institution: University of Southern California , University of Southern California
EPA Project Officer: Chung, Serena
Project Period: June 1, 1999 through May 31, 2005 (Extended to May 31, 2006)
Project Period Covered by this Report: June 1, 2001 through May 31, 2002
RFA: Airborne Particulate Matter (PM) Centers (1999) RFA Text |  Recipients Lists
Research Category: Air Quality and Air Toxics , Particulate Matter , Air


The objective of this research project is to focus on the central hypothesis of the Southern California Particle Center and Supersite, which is that organic constituents associated with particulate matter (PM)—including quinones, other organic compounds (polycyclic aromatic hydrocarbons [PAHs], nitro-PAHs, and aldehydes/ketones), and metals—are capable of generating reactive oxygen species and acting as electrophilic agents. They have a central role in allergic airway disease such as asthma and cardiovascular effects through their ability to generate oxidative stress, inflammation, and immunomodulating effects in the lungs and airways.

By taking measurements at three sites, one source and two receptor sites (the receptor sites are locations in which the PM composition has been modified by atmospheric chemistry), we hope to evaluate: (1) the role of atmospheric chemistry in the toxicity of PM and copollutants; and (2) if airway disease and cardiovascular effects are more severe during periods of high photochemical activity (summer) than in periods of low photochemical activity (winter). A mouse and a rat model are being used. The mouse model will be used to test the hypothesis that ambient particles can act as an adjuvant, and will contribute to the development of allergic and asthmatic responses. The rat model tests hypotheses related to the exacerbation of asthma.

Progress Summary:

For this study, ambient particle characteristics were measured over a 13 month period at three different receptor sites in the eastern portion of the Los Angeles Basin: Riverside, Rubidoux, and Claremont, CA. In fall 2002, we began PM sampling with the Particle Instrumentation Unit (PIU) at the University of Southern California (USC), our source site. A scanning mobility particle spectrometer/aerodynamic particle sizer tandem system was employed to collect continuous particle size distributions, from which particle number and mass concentrations were calculated. An aethalometer provided continuous particulate elemental carbon (EC).

At both Claremont and Riverside, diurnal patterns included a morning traffic peak indicated by increases in particle mass, number, and EC. Afternoon periods in the warmer months are characterized by high number counts, but mass and EC remain low, suggesting the formation of new particles by photochemistry. Although particle nucleation was not observed directly, the other possible causes of an increase in particle number can be discounted. Low EC levels indicate that vehicular emissions do not cause the afternoon increase in particle numbers. The inversion height increases in the afternoon. The particle size mode in the afternoon is smaller than in the morning, indicating that the aerosol has not grown during transport from urban sources.

Future Activities:

We will keep the PIU located at the USC source site through at least September 2003, completing a full year of sampling activity. We will continue exposure studies to investigate seasonal changes in toxicity near this urban site. Additionally, we will continue to make our mobile particle trailer available for colocated exposure studies. Animal inhalation toxicology studies using concentrated ambient particulates—investigating the hypotheses that atmospheric chemistry is important in the toxicity of PM and copollutants, airway injury, and cardiovascular effects—will be greater at receptor sites downwind of source sites along the mobile source trajectory in the Los Angeles Basin. Led by Drs. Harkema (University of Michigan), Kleinman (University of California at Irvine), and Froines and Nel (University of California at Los Angeles), these colocated studies have commenced during our first month at the USC site.

Journal Articles:

No journal articles submitted with this report: View all 66 publications for this subproject

Supplemental Keywords:

Particulate matter, quinones, PAHs, aldehydes, ketones, human health risk, asthma, cardiovascular effects, atmospheric chemistry, mobile sources, air toxics, environmental monitoring, photochemical activity, air sampling, California,, RFA, Health, Scientific Discipline, PHYSICAL ASPECTS, Air, Geographic Area, HUMAN HEALTH, particulate matter, Environmental Chemistry, Air Pollutants, State, Risk Assessments, Biochemistry, Health Effects, Physical Processes, ambient aerosol, asthma, children's health, aldehydes, epidemiology, quinones, exposure, allergic airway disease, air pollution, children, PAH, air sampling, aerosol composition, California (CA), allergens, aerosols, atmospheric chemistry, dosimetry

Relevant Websites:

http://www.scpcs.ucla.edu/ exit EPA

Progress and Final Reports:

Original Abstract
  • 1999
  • 2000
  • 2001 Progress Report
  • 2003 Progress Report
  • 2004
  • Final Report

  • Main Center Abstract and Reports:

    R827352    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).
    R827352C001 The Chemical Toxicology of Particulate Matter
    R827352C002 Pro-inflammatory and the Pro-oxidative Effects of Diesel Exhaust Particulate in Vivo and in Vitro
    R827352C003 Measurement of the “Effective” Surface Area of Ultrafine and Accumulation Mode PM (Pilot Project)
    R827352C004 Effect of Exposure to Freeways with Heavy Diesel Traffic and Gasoline Traffic on Asthma Mouse Model
    R827352C005 Effects of Exposure to Fine and Ultrafine Concentrated Ambient Particles near a Heavily Trafficked Freeway in Geriatric Rats (Pilot Project)
    R827352C006 Relationship Between Ultrafine Particle Size Distribution and Distance From Highways
    R827352C007 Exposure to Vehicular Pollutants and Respiratory Health
    R827352C008 Traffic Density and Human Reproductive Health
    R827352C009 The Role of Quinones, Aldehydes, Polycyclic Aromatic Hydrocarbons, and other Atmospheric Transformation Products on Chronic Health Effects in Children
    R827352C010 Novel Method for Measurement of Acrolein in Aerosols
    R827352C011 Off-Line Sampling of Exhaled Nitric Oxide in Respiratory Health Surveys
    R827352C012 Controlled Human Exposure Studies with Concentrated PM
    R827352C013 Particle Size Distributions of Polycyclic Aromatic Hydrocarbons in the LAB
    R827352C014 Physical and Chemical Characteristics of PM in the LAB (Source Receptor Study)
    R827352C015 Exposure Assessment and Airshed Modeling Applications in Support of SCPC and CHS Projects
    R827352C016 Particle Dosimetry
    R827352C017 Conduct Research and Monitoring That Contributes to a Better Understanding of the Measurement, Sources, Size Distribution, Chemical Composition, Physical State, Spatial and Temporal Variability, and Health Effects of Suspended PM in the Los Angeles Basin (LAB)