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DEVELOPMENT AND USE OF RARE EARTH TRACERS IN THE MODIFIED DRY PARTICLE DEPOSITION SYSTEM (FORMERLY "DUST" CHAMBER)
Citation:
Antley, J. T. AND J. Giglio. DEVELOPMENT AND USE OF RARE EARTH TRACERS IN THE MODIFIED DRY PARTICLE DEPOSITION SYSTEM (FORMERLY "DUST" CHAMBER). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-00/005 (NTIS PB2001-100351), 2000.
Impact/Purpose:
The objective of this task is to develop and employ PM measuring tools for EPA researchers and regulators to use to characterize the exposure of humans to PM of outdoor origin in both outdoor and indoor environments. Achieving these objectives will improve the scientific foundation for risk assessments of PM in future reevaluations of the NAAQS and in assessing exposure of humans to PM.
Description:
This report was submitted in partial fulfillment of Contract 68-D5-0040 by Research Triangle Institute under the sponsorship of the United States Environmental Protection Agency. This report covers a period from October 1, 1996 to September 30, 1999 and includes activities funded under Work Assignments I-12, II-24 and III-31.
The characterization of U.S. EPA's Dry Particle Deposition Chamber has been ongoing since the publication of EPA 600/R-96/106 ("Development and Evaluation of a Dry Particle Deposition Uniformity System with Transverse (DUST) to Generate Test Surfaces for House Dust Sampler Characterization, Re-entrainment, and Re-suspension Studies"). This report details the changes to the mechanical configuration, the operating procedures, the algorithms for data analyses, and the overall capabilities of the system.
Modifications of the hardware include design changes to the traversing system and the dust feeder carriage for increased stability.
Changes in operating procedures include a new dust plate loading mechanism and a new coupon configuration which provide a more representative measurement of the loaded surface. Tests in which the mass deposited on the surface was compared with the mass collected by the coupons allowed new algorithms to be developed for better prediction of surface loading.
Finally, a tagging procedure has been developed with the intended purpose of applying coatings of rare earth metals to discrete size fractions of surrogate dusts (Arizona Test Dust and glass beads). Extraction of metals from tagged particles may be analyzed by inductively coupled plasma mass spectrometry (ICP-MS) to determine particle fate and transport as a function of discrete particle size ranges. Due to the sensitivity of ICP-MS, lower surface loadings (0.1 g/m2) are not theoretically possible, much lower then when analyzing deposits gravimetrically (3 g/m2)
The U.S. Environmental Protection Agency through its Office of Research and Development funded and managed the research described here under EPA Contract No 68-D5-0040 to Research Triangle Institute. It has been subjected to the Agency's peer and administrative review and has been approved for publication as an EPA document. Mention of trade names or commercial products does not constitute endorsement or recommendation for use