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| Titel: |
Seasonal and Spatial Variation of Polycyclic Aromatic Hydrocarbons in Vapor-Phase and PM2.5 in Southern California Urban and Rural Communities |
| Auteur: |
Eiguren-Fernandez, Arantzazu Miguel, Antonio H. Froines, John R. Thurairatnam, Suresh Avol, L. |
| Verschenen in: |
Aerosol science and technology |
| Paginering: | Jaargang 38 (2004) nr. 5 pagina's 447-455 |
| Jaar: |
2004-05 |
| Inhoud: |
Fifteen priority polycyclic aromatic hydrocarbons (PAHs) were measured in two rural communities (Atascadero and Lompoc) located several hundred km northwest of Los Angeles and in four urban communities 40-100 km downwind of Los Angeles (San Dimas, Upland, Mira Loma, and Riverside), during all seasons, from May 2001 to July 2002. PM2.5 and vapor-phase PAHs were collected, on prebaked quartz fiber filters and PUF-XAD-4 resin, respectively, at 113 LPM, during 24 h periods, every eighth day, and quantified by HPLC-Fluorescence. At all sites vapor-phase PAHs contained > 99.9% of the total PAH mass and were dominated by naphthalene (NAP), which varied from about 60 ng m- 3 in Lompoc, a community with light traffic, to ∼580 ng m- 3 in Riverside, a community traversed by ∼200,000 vehicles day- 1. During summer pollution episodes in urban sites, NAP concentrations reached 7-30 times annual averages. Except for summer episodes, concentrations of low MW PAHs showed small seasonal variations (∼2 times higher in winter). Similar concentrations of particle-phase PAHs were observed at all sites except for Lompoc. Benzo[ghi]perylene (BGP), a marker of gasoline exhaust emissions, showed the highest concentration among particle-phase PAHs, varying from 23.3 pg m-3 in Lompoc to 193 pg m-3 in Mira Loma. Benzo[a]pyrene and indeno[1,2,3-cd]pyrene, found exclusively in the particle phase, were much higher in urban sites (∼40-100 pg m-3), than in Lompoc (∼12 pg m-3). Winter particle-phase PAHs were 2 to 14 times higher than summer levels. Particle-phase PAHs were negatively correlated with mean air temperature in urban sites (r = -0.50 to -0.75), probably resulting from surface inversions occurring during winter. The data suggest that in Southern California vehicular exhaust emissions are a major contributor to particle-phase PAHs. |
| Uitgever: |
Taylor & Francis |
| Bronbestand: |
Elektronische Wetenschappelijke Tijdschriften |
Details van artikel 8 van 11 gevonden artikelen
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