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| Titel |
Relationships between size-fractionated indoor and outdoor trace elements at four retirement communities in southern California |
| VerfasserIn |
A. Polidori, K. L. Cheung, M. Arhami, R. J. Delfino, J. J. Schauer, C. Sioutas |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 9, no. 14 ; Nr. 9, no. 14 (2009-07-15), S.4521-4536 |
| Datensatznummer |
250007499
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| Publikation (Nr.) |
 copernicus.org/acp-9-4521-2009.pdf |
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| Zusammenfassung |
| Indoor and outdoor water soluble trace elements (TEs) were analyzed on
quasi-ultrafine (UF), accumulation, and coarse PM filter samples collected
at four retirement communities, three located in the San Gabriel Valley and
one in Riverside, CA. Our analysis indicates that a complex mix of
vehicular, industrial, and soil-related emissions was responsible for the
elemental concentrations measured at the three San Gabriel sites, while
regional transport, soil re-suspension and, to a lower degree, local traffic
contributed to TE levels observed in Riverside. In the quasi-UF mode, the
magnitude of indoor/outdoor concentration ratios (I/O) for elements of
anthropogenic origin was highly variable, reflecting the spatial
heterogeneity of combustion sources in the study area. Indoor/outdoor
ratios in accumulation mode PM were closer to 1, and more homogeneous across
sites, indicating that elements associated with this size fraction penetrate
indoors with high efficiencies. The lowest overall I/O ratios were obtained
for elements found in coarse particles, consistent with the fact that only a
small portion of coarse outdoor PM infiltrates indoors. The potential of S
and other TEs to serve as tracers of indoor-penetrated particles of outdoor
origin was also examined. Our results suggest that using the I/O ratio of S
(I/OS) as a surrogate of the infiltration factor for PM2.5 [Finf(PM2.5)] might lead to an overestimation of the indoor PM2.5 originating outdoors. This is in contrast with what was reported in
previous studies conducted in the Eastern US, where S has been consistently
used as a reliable tracer of outdoor PM2.5 infiltrating indoors. Our
differences may be due to the fact that in the Los Angeles basin (and in
general in the Western US) PM2.5 includes a number of semi-volatile
labile species, such as ammonium nitrate and several organic compounds,
which volatilize either entirely or to a substantial degree upon building
entry. |
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