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INDIVIDUAL PARTICLE ANALYSIS OF INDOOR, OUTDOOR, AND COMMUNITY SAMPLES FROM THE 1998 BALTIMORE PARTICULATE MATTER STUDY
Citation:
Conner, T L., G A. Norris, M S. Landis, AND R W. Williams. INDIVIDUAL PARTICLE ANALYSIS OF INDOOR, OUTDOOR, AND COMMUNITY SAMPLES FROM THE 1998 BALTIMORE PARTICULATE MATTER STUDY. ATMOSPHERIC ENVIRONMENT 35(23):3935-3946, (2001).
Impact/Purpose:
The NERL SEM/EDX facility was established to provide a state-of-the-art resource for individual particle analysis. Specific goals of the laboratory are as follows: 1) Provide chemical, morphological, and size characterization of particles in support of ambient air characterization studies, source apportionment, exposure and health studies, and other particulate matter research.; 2) Develop analytical capabilities to support research objectives; 3) Communicate results to clients and the scientific community.
Description:
The United States Environmental Protection Agency (U.S. EPA) recently conducted the 1998 Baltimore Particulate Matter (PM) Epidemiology-Exposure Study of the Elderly. The primary goal of that study was to establish the relationship between outdoor PM concentrations and actual human PM exposures within a susceptible (elderly) sub-population. Personal, indoor, and outdoor sampling of particulate matter was conducted at a retirement center in the Towson area of northern Baltimore County. Concurrent sampling was conducted at a central community site. The main objective of this work was to use computer-controlled scanning electron microscopy with individual-particle X-ray analysis (CCSEM) to measure the chemical and physical characteristics of geological and trace element particles collected at the various sampling locations in and around the retirement facility.
The CCSEM results show that the relative abundances of some geological and trace element particle classes identified at the outdoor and community locations differ from each other and from the indoor location. Particle images acquired during the computer-controlled analyses played a key role in the identification of certain particle types. Review of these images was particularly useful in distinguishing spherical particles (usually indicative of combustion) from non-spherical particles of similar chemical composition. Pollens and spores were also identified through a manual review of the particle images.
This work has been funded wholly or in part by the U.S. Environmental Protection Agency (1997) under contract #68-D5-0040 to the Research Triangle Institute and under contract #68-D5-0049 to ManTech Environmental Technology, Inc. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.