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SOURCE APPORTIONMENT OF INDOOR, OUTDOOR, AND PERSONAL PM2.5 IN SEATTLE, WASHINGTON, USING POSITIVE MATRIX FACTORIZATION
Citation:
Larson, T., T. Gould, C. Simpson, L. Liu, C. S. Claiborn, AND J. JUNGERS. SOURCE APPORTIONMENT OF INDOOR, OUTDOOR, AND PERSONAL PM2.5 IN SEATTLE, WASHINGTON, USING POSITIVE MATRIX FACTORIZATION. JOURNAL OF AIR & WASTE MANAGEMENT ASSOCIATION 54(9):1175-1187, (2004).
Impact/Purpose:
The objective of this task is to develop and evaluate personal exposure and biomarker methods for toxic components associated with PM2.5 and SVOC in population exposures. Specific sub-objectives include the following:
1) Identification and quantification of either toxic or tracer organic chemicals associated with PM2.5 and associated SVOC.
2) Measurement of personal airborne exposure of selected toxic/tracer organic species in population based human exposure studies.
3) Development and application of urinary metabolite and other biomarker methods for these toxic/tracer organic species in human exposure studies.
4) Evaluation of multivariant receptor models for apportioning personal exposure using biomarker data.
Description:
As part of a large exposure assessment and health effects panel study, 33 trace elements and light-absorbing carbon were measured on 24-hr particulate matter with an aero-dynamic diameter <2.5 um (PM2.5) fixed-site filter samples collected between September 26, 2000, and May 25, 2001, at a central outdoor site, immediately outside each subject's residence, inside each residence, and on each subject (personal sample). Both two-way (PMF2) and three-way (PMF3) positive matrix factorization were used to deduce the sources contributing to PM2.5. Five sources contributing to the indoor and outdoor samples were identified: vegetative burning, mobile emissions, secondary sulfate, a source rich in chlorine, and a source of crustal-derived material. Vegetative burning contributed mor PM2.5 mass on average than any other source in all microenvironments, with average values estimated by PMF2 and PMF3, respectively, of 7.6 and 8.7 ug/m3 for the outdoor samples, 4 and 5.3 ug/m3 for the indoor samples, and 3.8 and 3.4 ug/m3 for the personal samples. Personal exposure to the combustion-related particles were correlated with outdoor sources, whereas exposure to the crustal and chlorine-rich particles was not. Personal exposures to crustal sources were strongly associated with personal activities, especially time spent at school among the child subjects.
This paper has been reviewed in accordance with the US EPA's peer and administrative review policies and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.