Temporal and spatial variations in organic and elemental carbon concentrations in PM10/PM2.5 in the metropolitan area of Costa Rica, Central America
Por:
Murillo, JH, Marin, JFR, Roman, SR, Guerrero, VHB, Arias, DS, Ramos, AC, Gonzalez, BC, Baumgardner, DG
Publicada:
1 ene 2013
Resumen:
PM2.5 and PM10 samples were collected at 4 and 14 sampling sites,
respectively, located in the Metropolitan area of Costa Rica (MACR),
during 2010-2011. These sites were representative of commercial,
industrial and residential zones of this region. Concentrations of
elemental carbon (EC) and organic carbon (OC) were analyzed using the
IMPROVE thermal-optical reflectance (TOR) method. OC and EC
concentrations were higher in commercial and industrial sites and showed
clear seasonal variations with higher concentrations observed in the
rainy season (May-November) than in the dry season (December-April), due
to wind patterns in the study area. Total carbonaceous aerosol accounted
for 35% of PM10 and 56% of PM2.5 mass. Good correlation between OC and
EC in PM10 (R=0.89-0.75) and PM2.5 (R= 0.79-0.64) indicated that they
had common dominant sources of combustion such as industrial activities
and traffic emissions. The annual average concentrations of estimated
SOC (Secondary Organic Carbon) in the MACR PM10 samples showed values
between 0.65-8.49 mu g/m(3), accounting for 48% and 56% of the OC in
PM10 and PM2.5 respectively. Positive Matrix Factorization (PMF)
identified five principal sources for OC and EC in particles: gasoline
vehicles, diesel vehicles, on road traffic, wood smoke and industrial
combustion. The contribution of each of the source varied between the
PM10 and PM2.5 size fractions.
Filiaciones:
Baumgardner, DG:
Univ Nacl Autonoma Mexico, Ctr Ciencias Atmosfera, Mexico City 04510, DF, Mexico
All Open Access; Hybrid Gold
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