1999 Progress Report: Characterization of Fine Particulate Matter

EPA Grant Number: R827355C004
Subproject: this is subproject number 004 , established and managed by the Center Director under grant R827355
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: Airborne PM - Northwest Research Center for Particulate Air Pollution and Health
Center Director: Koenig, Jane Q.
Title: Characterization of Fine Particulate Matter
Investigators: Covert, David S. , Elleman, Rob , Kim, Eugene , Larson, Timothy V.
Current Investigators: Covert, David S. , Haneuse, Sebastien , Koenig, Jane Q. , Larson, Timothy V. , Lumley, Thomas , Schreuder, Astrid
Institution: University of Washington
EPA Project Officer: Chung, Serena
Project Period: June 1, 1999 through May 31, 2004 (Extended to May 31, 2006)
Project Period Covered by this Report: June 1, 1999 through May 31, 2000
Project Amount: Refer to main center abstract for funding details.
RFA: Airborne Particulate Matter (PM) Centers (1999) RFA Text |  Recipients Lists
Research Category: Air Quality and Air Toxics , Particulate Matter , Air

Objective:

The goal of this project within the PM Center is to measure the physical and hygroscopic properties of the aerosol in the urban areas where the health studies are being done during the first 4 years and then to incorporate these data into respiratory deposition models and mesoscale transport models. The physical properties to be measured are the number-size distribution from 10 nm to 10,000 nm diameter. The hygroscopic properties are the diameter growth factor for the submicrometric size range for humidities up to 90 percent RH with extrapolation to 100 percent via Koehler theory.

Progress Summary:

Two identical size distribution measurement systems have been assembled. They consist of differential mobility analyzers (DMA), condensation particle counters (CPC), and Aerodynamic Particle Sizers (APS). The DMA-CPC sizes particles in the size range 10 to 600 nm. The APS sizes particles in the range 500 to 10,000 nm. They have been integrated and connected to computers for instrument control and data acquisition. The program driving the instruments is optimized to get high statistical significance in the size range from 100 to 2,500 nm where traditional programs have large Poisson uncertainties. This is the size range of greatest importance to PM2.5 health studies because the majority of the mass is in this increment. The instruments have been tested in the laboratory under parallel sampling conditions to test the precision of the systems. This is a necessary first order test because they will be operated in the field at two sites, and the data will be analyzed for differences between them as a measure of aerosol evolution with advection along an air mass trajectory. The sampling inlet and other logistical preparations at the measurement site on Beacon Hill have been completed.

Data analysis schemes have been developed and tested for fitting log normal curves to the data to determine modal concentrations, mean sizes, and standard deviations for eventual statistical analysis. This testing is needed to quantify and minimize the uncertainty in the output resulting from operator subjectivity and program initialization. The hygroscopic growth measurement system, a Tandem Differential Mobility Analyzer (TDMA), which uses an APS as a detector above 600 nm, has been assembled in the laboratory. Testing with inorganic salts and dicarboxylic acids representative of the atmospheric aerosol chemistry is underway. A theoretical study of particle growth at humidities up to 100 percent has been done using modified Koehler theory, which includes the effects of slightly soluble organic compounds. This will be used to extrapolate the observational data at humidities up to the instrumental limit of 90 percent to the respiratory humidities up to 99+ percent.

A separate instrumental system consisting of two CPCs and an optical particle counter (OPC) to measure the aerosol number-size distribution outdoors and at three indoor locations within 5 meters has been assembled. Presently, it is being tested in the field as part of another project. This system measures the size distribution in 5 increments between 10 and 1,000 nm, trading size resolution for spatial resolution. It switches between the four inlets on a 20-minute cycle with a 4-minute measurement at each location.

Future Activities:

Testing with inorganic salts and dicarboxylic acids will continue, and observational data will be collected from the study of particle growth at humidities up to 100 percent.

Journal Articles:

No journal articles submitted with this report: View all 5 publications for this subproject

Supplemental Keywords:

ambient particles, fine particles, combustion, health, exposure, biostatistics, susceptibility., RFA, Scientific Discipline, Air, Geographic Area, Ecosystem Protection/Environmental Exposure & Risk, particulate matter, Environmental Chemistry, Health Risk Assessment, State, Monitoring/Modeling, Biochemistry, indoor air, Atmospheric Sciences, ambient aerosol, environmental monitoring, fate and transport, particle size, particulates, atmospheric dispersion models, atmospheric measurements, hygroscopic properties, environmental measurement, ambient air, air pollution, Washington (WA), particulate matter mass, size distribution monitoring, indoor air quality, ecological models, transport modeling, aerosol analyzers, aerosols, air quality, dosimetry

Relevant Websites:

http://depts.washington.edu/pmcenter/ Exit EPA icon

Progress and Final Reports:

Original Abstract
  • 2000 Progress Report
  • 2001 Progress Report
  • 2002
  • 2003 Progress Report
  • 2004
  • Final Report

  • Main Center Abstract and Reports:

    R827355    Airborne PM - Northwest Research Center for Particulate Air Pollution and Health

    Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
    R827355C001 Epidemiologic Study of Particulate Matter and Cardiopulmonary Mortality
    R827355C002 Health Effects
    R827355C003 Personal PM Exposure Assessment
    R827355C004 Characterization of Fine Particulate Matter
    R827355C005 Mechanisms of Toxicity of Particulate Matter Using Transgenic Mouse Strains
    R827355C006 Toxicology Project -- Controlled Exposure Facility
    R827355C007 Health Effects Research Core
    R827355C008 Exposure Core
    R827355C009 Statistics and Data Core
    R827355C010 Biomarker Core
    R827355C011 Oxidation Stress Makers