HR: 1400h
AN: A43A-10    [Abstracts]
TI: Levels, Composition and Sources of PM in the Mexico City Metropolitan Area During the MILAGRO Campaign
AU: QUEROL, X
EM: xavier.querol@ija.csic.es
AF: Institute of Earth Sciences "Jaume Almera" CSIC, Lluís Solé i Sabarís s/n, Barcelona, 08028, Spain
AU: * PEY, J
EM: jpey@ija.csic.es
AF: Institute of Earth Sciences "Jaume Almera" CSIC, Lluís Solé i Sabarís s/n, Barcelona, 08028, Spain
AU: MINGUILLON, M C
EM: mminguillon@itc.uji.es
AF: Institute of Earth Sciences "Jaume Almera" CSIC, Lluís Solé i Sabarís s/n, Barcelona, 08028, Spain
AU: PEREZ, N
EM: nperez@ija.csic.es
AF: Institute of Earth Sciences "Jaume Almera" CSIC, Lluís Solé i Sabarís s/n, Barcelona, 08028, Spain
AU: ALASTUEY, A
EM: aalastuey@ija.csic.es
AF: Institute of Earth Sciences "Jaume Almera" CSIC, Lluís Solé i Sabarís s/n, Barcelona, 08028, Spain
AU: MORENO, T
EM: tmoreno@ija.csic.es
AF: Institute of Earth Sciences "Jaume Almera" CSIC, Lluís Solé i Sabarís s/n, Barcelona, 08028, Spain
AU: BERNABE, R
EM: rbernabe@ine.gob.mx
AF: National Center for Environmental Research and Training, CENICA, CENICA - INE- SEMARNAT Av San Rafael Atlixco 186 Col Vicentina Del Iztapalapa, Mexico City, 09340, Mexico
AU: blanco, S
EM: sblanco@ine.gob.mx
AF: National Center for Environmental Research and Training, CENICA, CENICA - INE- SEMARNAT Av San Rafael Atlixco 186 Col Vicentina Del Iztapalapa, Mexico City, 09340, Mexico
AU: CARDENAS, B
EM: bcar@xanum.uam.mx
AF: National Center for Environmental Research and Training, CENICA, CENICA - INE- SEMARNAT Av San Rafael Atlixco 186 Col Vicentina Del Iztapalapa, Mexico City, 09340, Mexico
AB: Particle air pollution in urban agglomerations comes mostly from anthropogenic sources, mainly traffic, industrial processes, energy production, domestic and residential emissions, construction, but also a minor contribution from natural sources may be expected (bioaerosols, soil dust, marine aerosol). Once emitted into the atmosphere, this complex mixture of pollutants may be transformed as a function of the ambient conditions and the interaction among the different PM components, and also between PM components and gaseous pollutants. This system is especially complex in mega-cities due to the large emission volumes of PM components and gaseous precursors, the high variability and broad distribution of emission sources, and the possible long range transport of the polluted air masses. Speciation studies help to identify major sources of PM components with the end objective of applying plans and programs for PM pollution abatement. In this framework, concentration levels and compositions of particulate matter (PM2.5, PM10 and TSP) have been measured simultaneously at two sites in the Mexico City Metropolitan Area (T0 and CENICA) and at one site 50 km away from Mexico City (T1) during the MILAGRO campaign (1st to 31st March 2006). Spatial and time (day and night) variations have been analysed. Coarse fraction levels were higher at T1 than at CENICA and T0, contrary to what was expected. This was due to the important soil re-suspension at T1, contributing significantly to the crustal load. Moreover, crustal levels were higher during daytime than during nights at all sites, while some secondary compounds (sulphate and ammonium) presented an opposite trend. Regarding trace elements, levels of Pb, Zn and Cd were higher at T0 than at CENICA and T1, probably due to traffic contribution. Arsenic levels did not show a clear pattern, being alternatively higher at CENICA and T0. Two intense episodes of Hg particulate have been recorded, more noticeable at T1 than at the urban sites. V and Ni showed the same evolution at all sites and fractions, being alternatively higher at the three sites. In order to identify the sources of the studied pollutants, a statistical analysis has been carried out. Crustal, regional and industrial sources were identified at the three sites. Moreover, traffic and fuel combustion sources were found at the urban sites. Finally, a metallurgy source was detected at T1 and CENICA. Nevertheless these results must be considered as indicative of the possible sources but not completely definitive due to the relative low number of samples.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
SC: Atmospheric Sciences [A]
MN: 2007 Joint Assembly