Some factors such as the high population growth, along with insufficient ho
using, health and sanitary services, obsolete industrial technology and the
lack of environmental management programs, give rise to contamination in L
atin-American cities. Owing to the urban characteristics of San Luis, a det
ailed analysis of air quality was planned as part of a more comprehensive s
tudy, in order to make an environmental diagnosis of the city after the dem
ographical and economic upgrowth over the last 15 years. It has been conclu
ded that air pollution levels in San Luis are higher than those expected fo
r a medium-size city. The reported high levels were attributed to important
industrial activity, responsible not only for the direct of polluting gase
s to the atmosphere but also as the principal cause of the urban expansion.
The levels of CO and SO2 (ppm) found in the city can be considered as high
. Some weeks during the sampling measure values were appreciably higher tha
n the maximum tolerance levels established. The urban area under study was
separated into five defined areas, which allowed to make comparisons in ord
er to identify specific contamination problems. The slopes corresponding to
the plot polluting substances concentration vs. wind speed were lower than
the expected values. Because of the urban area characteristics, different
micrometeorological effects facilitating a low air exchange can be generate
d, and consequently increasing the contamination levels. Thus, it is correc
t to conclude that the degradation processes are not occurring in a single
environmental plane. Accordingly, air contamination rate in San Luis city c
ould be considered as evidence of other upper-scale regional environmental
degradation processes.