Atmospheric Gas-Particle Partitioning of Polycyclic Aromatic Hydrocarbons in High Mountain Regions of Europe
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- 作者：Pilar Ferná ; ndez ; Joan O. Grimalt ; and Rosa M. Vilanova
- 刊名：Environmental Science & Technology
- 出版年：2002
- 出版时间：March 15, 2002
- 年：2002
- 卷：36
- 期：6
- 页码：1162 - 1168
- 全文大小：113K
- 年卷期：v.36,no.6(March 15, 2002)
- ISSN：1520-5851
文摘
Atmospheric concentrations and gas-particle partitioningof polycyclic aromatic hydrocarbons (PAH) have beendetermined at three remote mountain areas in Europe. Gas-phase mean concentrations of total PAH (20 individualcompounds) were very similar at all sites, ranging from 1.3-2.6 ng m-3 in the Pyrenees (Spain) to 2.7-3.7 ng m-3 inthe Alps (Austria) and Caledonian mountains (Norway). Aseasonal variability was observed, with the highestlevels found in winter. The seasonal differences werereflected better in the particle-associated PAH, showingthe increase of PAH emissions in the colder months and atemperature dependence of the gas-particle partitioning.Significant geographical differences were also observed forparticulate PAH, indicating a greater influence of regionalsources than in the gas phase. Partitioning of PAHbetween gas and particulate phases was well-correlatedwith the subcooled liquid vapor pressure in all samples, butwith slopes significantly steeper than the expected valueof -1. These steeper slopes may reflect the occurrence ofa nonexchangeable PAH fraction in the aerosols, likelyassociated to the soot carbon phase. Comparison of absorptionto organic matter and soot carbon using the octanol-air(Koa) and soot-air (Ksa) partitioning coefficients shows that,despite uncertainties on estimated organic matter andsoot carbon contents in the sampled aerosols, Koaunderpredicts aerosol PAH concentrations by a factor of0.6-2 log units. In contrast, predicted and measured highmountain aerosol PAH differ by 0.2-0.6 log units whenKsa is considered. The results point to soot carbon as themain transport medium for the long-range distribution ofaerosol-associated PAH.