title: Spatial differences in outdoor PM10 mass and aerosol composition in Mexico City.
abstract: Twenty-five MiniVol samplers were operated throughout the Mexico City metropolitan region from February 22 through March 22, 1997, to evaluate the variability of PM10 concentrations and composition. The highest PM10 concentrations were found in neighborhoods with unpaved or dirty roads, and elements related to crustal material were the main cause of differences from nearby (<200 m) monitors that were not adjacent to the roadbed. SO4(2-) concentrations were homogeneous across the city. SO4(2-) measured at the city boundaries was about two-thirds of the concentrations measured within the urbanized area, indicating that most SO4(2-) is of regional origin. Elemental carbon (EC) and organic carbon (OC) concentrations were highly variable, with higher concentrations in areas that had high diesel traffic and older vehicles. Spatial correlations among PM10 concentrations were high, even though absolute concentrations were variable, indicating a common effect of meteorology on the concentration or dispersion of local emissions.
authors: Desert Research Institute, University and Community College System of Nevada, Reno, 89512, USA.
authors: Judith C
authors: JC
authors: Chow
authors: John G
authors: JG
authors: Watson
authors: Sylvia A
authors: SA
authors: Edgerton
authors: Elizabeth
authors: E
authors: Vega
authors: Elba
authors: E
authors: Ortiz
mesh_terms: D000336:Aerosols / Q000032:analysis; D000393:Air Pollutants / Q000032:analysis*; D004784:Environmental Monitoring; D008800:Mexico
chemical_list: D000336:Aerosols; D000393:Air Pollutants