2006 Progress Report: PM Characterization and Exposure Assessment (Project 2)

EPA Grant Number: R832417C002
Subproject: this is subproject number 002 , established and managed by the Center Director under grant R832417
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: Johns Hopkins Particulate Matter Research Center
Center Director: Samet, Jonathan M.
Title: PM Characterization and Exposure Assessment (Project 2)
Investigators: Geyh, Alison , Breysse, Patrick N.
Current Investigators: Geyh, Alison , Breysse, Patrick N. , Chillrud, Steven , Datta, Saugatta , Han, Inkyu , Ondov, John M. , Ramos-Bonilla, Juan , Rule, Ana
Institution: The Johns Hopkins University
Current Institution: The Johns Hopkins University , Kansas State University , Lamont-Doherty Earth Observatory , University of Maryland
EPA Project Officer: Chung, Serena
Project Period: October 1, 2005 through September 30, 2010
Project Period Covered by this Report: October 1, 2005 through September 30, 2006
RFA: Particulate Matter Research Centers (2004) RFA Text |  Recipients Lists
Research Category: Health Effects , Air

Objective:

The focus of Project 2 is the measurement of specific chemical components and physical characteristics of PM from different areas of the country in support of the Center focus, which is assessing characteristics of PM that determine toxicity. The goals of Project 2 are to collect bulk PM samples for use in biological assays and for detailed characterization including mass, inorganic ions, elemental carbon and organic compounds, specifically polycyclic aromatic hydrocarbons, elemental metals and their oxides, and sulfur isotope ratios. We will also collect information on particle size. The objectives of Project 2 include: 1) the development of methods for collecting bulk ambient PM and a system for characterizing the chemical and physical properties of ambient PM; 2) the identification of specific regional differences in PM characteristics that may contribute to differential biological responses demonstrated by in vitro and in vivo bioassay systems; 3) the assessment of a relationship between human exposure to PM2.5 and biological response during a high PM2.5 exposure period and a low PM2.5 exposure period. The goals and objectives have remained unchanged over this time period.

Progress Summary:

Over the last several months, work to address Objective 1 has involved the identification and testing of two commercially available candidate cyclone systems for bulk PM collection. The candidate cyclones include the HVS3 (SC3, Inc.; Sandpoint, ID), and the Clear-Vue (Clear Vue Cyclones, Inc.; Pickens, SC). The HVS3 has been used previously by the Division of Environmental Health Engineering for bulk PM sample collection. It has a theoretical lower cut size (at 50% aerodynamic diameter) of 0.8 μm at a collection rate 1,000 L/min. The Clear Vue was designed as an air cleaning device for small hobbyist wood shops. It has a theoretical lower cut size of 2.5 μm at a flow rate of 3,700 L/min. Verification of these sampling parameters and lower cut sizes has been conducted at the Aerosol Laboratory of the Edgewood Chemical and Biologic Center using fluorescence of a monodisperse aerosol. By generating a controlled aerosol of known particle size and concentration, we evaluated collection characteristics of each cyclone. The reference 100% fluorescence was determined by collecting the aerosol on a filter. The HVS3 cyclone showed 100% retention of the smallest particle size tested, 1.7 μm, whereas the Clear Vue cyclone showed only a 60% retention for 1.7 μm particles. Testing continues and will include experiments with smaller particle sizes (1.0 μm and 0.5 μm). The upper cut size will also be determined. We currently have tested up to 9.5 μm where we have found 100% collection efficiency. In addition to testing commercially available single stage cyclone systems, we have designed a sequential cyclone system for bulk PM collection in 3 discrete size fractions. This system includes 3 cyclones connected in series in order to collect particles > PM10, particles between PM10 and PM2.5, and particles between PM2.5 and a lower cut size near 0.5 μm. Three machine shops have been approached to produce a prototype and we are waiting for estimates from each shop for this job.

A preliminary particle collection campaign using the single stage HVS3 cyclone was conducted in 2 bores of the Ft. McHenry tunnel, Baltimore, MD. The purposes of this campaign were to collect bulk PM with different source signatures (i.e., one bore has traffic comprised of 2% trucks while the other bore has approximately 20% truck traffic) and begin to develop approaches to bulk PM characterization. A range of measurements was part of this campaign including traffic counts, mass and number concentration, particle size distributions, and bulk PM collection. The bulk particles have been initially characterized for elements (Dr. Steven Chillrud-Lamont, Doherty Earth Observatory, Columbia University [CU]); CU is a subcontractor for Project 2. While total vehicle counts were higher in the bore carrying predominately cars (160,873 vs. 150,170) mass concentration was 50% to 100% lower than in the bore enriched in heavy duty vehicles. The elemental composition of the PM between the two bores did not differ significantly between bores, however. Samples of bulk PM collected during this campaign were provided to Project 3 for methods development.

Work to address Objective 2 has involved the renovation of an 8 ft x 24 ft trailer. The trailer was used for particle characterization by the Baltimore Super Site (BSS—PI John Ondov) and is located in Lake Clifton Park, Baltimore, MD. The trailer was damaged by arson on September 14, 2001. To prepare the trailer for re-use we have removed all damaged furniture and equipment, have had the interior and AC system cleaned by professional cleaners, and had the trailer inspected for roadworthiness. The interior has been redesigned to accommodate the current suite of sampling equipment and builders have been contracted to perform the renovations.

We have purchased the following equipment: a model 5020 sulfate particle analyzer (Thermo Electron Corp., Franklin, MA) to replace the analyzer used by UMD for the BSS that is no longer functional and a series 8500 Filter Dynamic Measurement System to interface with the Series 1400 TEOM. (Thermo Electron Corp., Franklin, MA). This was recommended for use on the road as a more reliable and less costly method for filter-based particle sampling in place of the Partisol FRM Model 2000 which is owned by JHSPH.

Work to address Objective 3 has involved the development of a protocol to collect and analyze exhaled breath condensates (EBC). We have completed an extensive literature review of existing methods for collecting EBC and laboratory methods for analyzing the condensate. The literature indicates that there exists no standardized protocol for the collection of EBC; therefore, we have begun work to establish a protocol that will meet the needs of our exposure assessment study. For the collection of EBC we have purchased the RTube (Respiratory Research, Inc., Charlottesville, VA), which is the principal EBC collection system in the United States. The RTube is registered with the U.S. Food and Drug Administration as a Class I device. The procedure for collecting EBC involves breathing normally into the device for 10–15 minutes. Issues to be resolved include sample collection temperature, sample handing, storage temperature, limitations in storage timing, and determination of the likely sample collection volume. We are refining the method described by Gallati and Pracht (Journal of Clinical Chemistry and Clinical Biochemistry 1985;23:453-460) for analysis of H2O2 in the condensate and are developing a protocol to identify metals in the condensate using a method described by Mutti, et al. (Chest 2006;129:1288-1297) as a guide.

Future Activities:

During the next 6 months, we will complete the characterization of the commercially available cyclones and begin bulk PM sample collection in Baltimore City at the JHSPH. We will manufacture and test the prototype sequential cyclone system. We will complete the renovation of the trailer, and install all monitoring equipment, as well as establish the networking system for data management and storage. We will finalize the protocol for collection of EBC and the laboratory analysis of H2O2 and metals. We will begin to develop the algorithm for forecasting high and low PM days in conjunction with Project 1 and will continue to collect bulk PM for Project 3 method development.

Journal Articles:

No journal articles submitted with this report: View all 13 publications for this subproject

Supplemental Keywords:

bulk particle collection, cyclone, exhaled breath condensate, markers of inflammation,, RFA, Health, Scientific Discipline, PHYSICAL ASPECTS, Air, particulate matter, Health Risk Assessment, Epidemiology, Risk Assessments, Physical Processes, atmospheric particulate matter, atmospheric particles, long term exposure, acute cardiovascular effects, airway disease, exposure, human exposure, ambient particle health effects, atmospheric aerosol particles, ultrafine particulate matter, aersol particles, particulate matter components, cardiovascular disease

Progress and Final Reports:

Original Abstract
  • 2007 Progress Report
  • 2008 Progress Report
  • 2009 Progress Report
  • Final Report

  • Main Center Abstract and Reports:

    R832417    Johns Hopkins Particulate Matter Research Center

    Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
    R832417C001 Estimation of the Risks to Human Health of PM and PM Components
    R832417C002 PM Characterization and Exposure Assessment (Project 2)
    R832417C003 Biological Assessment of the Toxicity of PM and PM Components