Title: | Atmospheric gas-particle partitioning of polycyclic aromatic hydrocarbons in high mountain regions of Europe |
Author(s): | Fernandez P; Grimalt JO; Vilanova RM; |
Address: | "Department of Environmental Chemistry, Institute of Chemical and Environmental Research, CSIC, Barcelona, Catalonia, Spain. pfrqam@iiqab.csic.es" |
ISSN/ISBN: | 0013-936X (Print) 0013-936X (Linking) |
Abstract: | "Atmospheric concentrations and gas-particle partitioning of polycyclic aromatic hydrocarbons (PAH) have been determined at three remote mountain areas in Europe. Gas-phase mean concentrations of total PAH (20 individual compounds) 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) in the Alps (Austria) and Caledonian mountains (Norway). A seasonal variability was observed, with the highest levels found in winter. The seasonal differences were reflected better in the particle-associated PAH, showing the increase of PAH emissions in the colder months and a temperature dependence of the gas-particle partitioning. Significant geographical differences were also observed for particulate PAH, indicating a greater influence of regional sources than in the gas phase. Partitioning of PAH between gas and particulate phases was well-correlated with the subcooled liquid vapor pressure in all samples, but with slopes significantly steeper than the expected value of -1. These steeper slopes may reflect the occurrence of a nonexchangeable PAH fraction in the aerosols, likely associated to the soot carbon phase. Comparison of absorption to organic matter and soot carbon using the octanol-air (Koa) and soot-air (Ksa) partitioning coefficients shows that, despite uncertainties on estimated organic matter and soot carbon contents in the sampled aerosols, Koa underpredicts aerosol PAH concentrations by a factor of 0.6-2 log units. In contrast, predicted and measured high mountain aerosol PAH differ by 0.2-0.6 log units when Ksa is considered. The results point to soot carbon as the main transport medium for the long-range distribution of aerosol-associated PAH" |
Keywords: | Absorption Aerosols Air Pollutants/*analysis Carbon/chemistry Environmental Monitoring Europe Gases Particle Size Polycyclic Aromatic Hydrocarbons/*analysis/chemistry Volatilization; |
Notes: | "MedlineFernandez, Pilar Grimalt, Joan O Vilanova, Rosa M eng Research Support, Non-U.S. Gov't 2002/04/12 Environ Sci Technol. 2002 Mar 15; 36(6):1162-8. doi: 10.1021/es010190t" |