Source Apportionment of Indoor, Outdoor, and Personal PM^sub 2.5^ in Seattle, Washington, Using Positive Matrix Factorization

• Published in: Journal of the Air & Waste Management Association (1995) Vol. 54; no. 9; p. 1175
• Main Authors: Larson, Timothy, Gould, Timothy, Simpson, Chris, L-J, Sally Liu
• Format: Journal Article
• Language: English
• Published: Pittsburgh Taylor & Francis Ltd 01.09.2004
• Subjects: Environmental engineering; Human exposure; Vehicle emissions; Seattle Washington
• ISSN: 1096-2247; 2162-2906

As part of a large exposure assessment and health-effects panel study, 33 trace elements and light-absorbing carbon were measured on 24-hr fixed-site filter samples for particulate matter with an aerodynamic diameter <2.5 µm (PM^sub 2.5^) 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 PM^sub 2.5^. 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 more PM^sub 2.5^ 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 µg/m^sup 3^ for the outdoor samples, 4 and 5.3 µg/m^sup 3^ for the indoor samples, and 3.8 and 3.4 µg/m^sup 3^ for the personal samples. Personal exposure to the combustion-related particles was 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. [PUBLICATION ABSTRACT]