P. Cicerofernandez et al., TSP, PM10 AND PM10 TSP RATIOS IN THE MEXICO-CITY METROPOLITAN-AREA - A TEMPORAL AND SPATIAL APPROACH/, Journal of exposure analysis and environmental epidemiology, 3, 1993, pp. 1-14
Data for PM10 and TSP collected from SEDUE's (Secretary of Urban Devel
opment and Ecology) five principal air monitoring stations from March
of 1988 to March of 1989 were analyzed with an emphasis on spatial and
temporal distributions. The Mexico City sites consisted of a mixed re
sidential and industrial setting in the NW, a highly industrialized ar
ea in the NE, the commercial and administrative district downtown, and
areas in the SW and SE dominated by residential neighborhoods. High v
olume samplers for TSP and PM10 running in parallel were used followin
g a protocol similar to the one specified by the U.S. Environmental Pr
otection Agency. The individual data collected ranged from 24 to 1494
mug/m-3 for TSP and from 17 to 607 mug/m-3 for PM10. The PM10-to-TSP r
atios ranged from 0.104 to 0.914 for a one year period, 0.495 being th
e overall mean ratio. Seasonal and geographical differences in this ra
tio may reflect the range of sources, transport and transformations of
primary and secondary particles. High concentrations of particles wer
e found during the winter and early spring, followed by relatively low
concentrations during the summer. Statistically significant differenc
es were found for the two most contrasting sites, the NE and SW areas
of the city. The northern and eastern parts were the most impacted by
particulate matter, while the area at the southwestern edge of the cit
y was least polluted by fine and total suspended particles.