2000 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, 2000 through May 31, 2001
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


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:

Size Distribution Monitoring

Aerosol number-size distribution is being monitored at the Beacon Hill site in Seattle. This measurement began in November 2000, after the Washington State Department of Ecology (DOE) and the Puget Sound Clean Air Agency moved to their new building at the site and will continue for at least 3 years to observe the seasonal and particulate source variability. The size distribution includes the size range from 20 nm to 10:m diameter covering the Aitken, accumulation, and coarse modes and can be integrated over any desired size increment (e.g., PM2.5). Data are gathered every 10 minutes to be able to measure and identify short-term variability in particle number concentration and the derived moments (surface area, volume and light scattering) of the aerosol. The data are being analyzed for time and size covariance to relate the features of the data set to chemical information collected concurrently at the site to identify aerosol sources. The size monitoring protocol and quality assurance is being coordinated with Principal Investigators at the U.S. Environmental Protection Agency (USEPA) Supersites.

The results of the principle component analysis of the first 3 months of the data have shown that there are several identifiable subsets of the size distribution that are related to either sources or a combination of sources and wind direction. A comparison with chemical analyses to identify these sources more positively is not feasible at this time due to the coarse, 24-hour, time resolution of the chemical samples. In the next year, there will be particulate chemical analysis on a matching time scale.

During the winter season, November through January, three homes were monitored for differences in indoor, outdoor aerosol number-size distribution in parallel with the more routine aerosol monitoring of the selected study subjects. A station wagon packed with sizing instrumentation was parked outside subjects' homes having adequate access to power and windows. Two sampling lines were led into the house and placed at different activity locations, while one sampling line was placed at an open location outside the house. The instrumentation was switched between the lines on a 5-minute time basis to collect a complete set of data every 15 minutes. Preliminary analysis shows that there were marked differences in overall concentration between the indoor and outdoor locations but not a significant difference in the form of the size distribution. Further analysis, including principle component analysis similar to that being done on the Beacon Hill size distribution data and comparison to the other monitoring data in subjects homes, will be done in Year 3.

Collaboration With Pacific Northwest National Laboratory (PNNL)

PNNL has initiated the PNW2001 field campaign in collaboration with Environment Canada to study photochemical air pollution in the Puget Sound and Fraser River Valley air shed during the late-summer season, August 15 through September 15, 2001. We have engaged ourselves in this study to provide monitoring of particle formation in support of the study. Additional instrumentation has been secured and integrated into the sizing system at the Beacon Hill site. A particulate monitoring package has been designed and fabricated for use in the PNNL G-1 aircraft that will map the photochemically active regions of Puget Sound. Flight plans have been established to compare the aircraft measurements with the Beacon Hill site through nearby landing and take-off patterns from Boeing Field in Seattle. This coordinated and collaborative experiment will yield a combined data set with a time series at two urban sites coupled with the 3 dimensional mapping of aerosol fields from the aircraft. This will provide a data set with added power that could not have been obtained otherwise to test the CMAQ models.

Future Activities:

Future activities will included size distribution monitoring, measurement of hygroscopic properties, and transport modeling.

Size Distribution Monitoring: During Year 3, we will continue to collect and analyze the size distribution data at Beacon Hill. An additional size monitor will be operated at a site 15 km north of Beacon Hill at the National Oceanic and Atmospheric Administration's (NOAA) Pacific Marine Environmental Laboratory. This site is in a location that is minimally impacted by local residential, industrial, or mobile sources to compare this slightly aged, urban aerosol to that at the more central site.

Hygroscopic Properties: Measurement of the hygroscopic properties of the aerosol (i.e., the change in size of the particles at high humidity) will be made in the next year to provide additional input data for modeling pulmonary deposition. The hygroscopic growth measurement system, a tandem differential mobility analyzer, has been developed for a related project and will be operated at the NOAA site in parallel with the second sizing system.

Transport Modeling: Modeling of the sources and transport of the aerosol using the MM5 (mesoscale model) to predict wind and other meteorological fields will be started in June of 2001. Several meetings, workshops, and conference presentations have taken place to start this new effort. We will use the CMAQ code in Models 3 developed by USEPA to predict the modal aerosol fields in time and space in the Puget Sound region. The source emission inventory will be based on work done by EPA Region 10 and the Washington State DOE. The CMAQ code has been determined to be the best available for this study and will mesh well with ongoing studies of gas phase transport and processing in the Puget Sound region. The size distribution data that we are collecting will be used to validate and improve the processes in the particulate subroutines of the model. The ground work for this effort has been done in close cooperation with modelers at EPA Region 10 and Washington State University and the members of the Northwest Regional Modeling Consortium. The required basic computer facilities have been identified within the Atmospheric Sciences Department, and the required additional terminals and storage media have been selected. This project will begin this summer quarter (June 2001) after the Atmospheric Sciences student recruited for this project completes his course work and qualifying exam.

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, Region 10., 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
  • 1999 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