SPATIAL DISTRIBUTION OF SO2, NOX AND O3 CONCENTRATIONS IN THE ENVIRONMENT OF MANIZALES

Spatial profiles of ambient concentrations of sulfur dioxide (SO2), nitrogen oxides (NOX) and tropospheric ozone (O-3) were determined by passive samplers in the Andean city of Manizales, Colombia. The study was performed in order to establish baseline concentrations of these contaminants in ambient air, and to analyze the influence of natural and anthropogenic local emission sources. Measurements were performed in 12 points located between urban and rural areas in the city, considering the wind direction on which the emission of the active volcano Nevado del Ruiz is dispersed. Three monitoring campaigns were carried out with duration of four weeks per campaign. Average SO2 concentrations ranged from 4.1 to 9.8 mu g/m(3) among the different monitoring points, suggesting the influence of industrial activity and the Nevado del Ruiz volcano. Average concentrations of NOX ranged from 5.9 to 82.2 mu g/m(3), with higher concentrations in points influenced by high vehicular traffic. O-3 concentrations ranged from 16.1 to 68.1 mu g/m(3), with highest concentrations in the rural area.