The travel patterns observed in large Brazilian cities present substantial percentage of bus travel, around 60%, and car ownership and use have been growing very fast for the past ten years. Besides this intense use of road transport, pollutant dispersion conditions are frequently poor because of high building construction and consequently, higher population densities. This paper presents the analysis of the main results which have been obtained from an extensive data collection carried out in ten different locations situated in the city of Rio de Janeiro. The analysis have been conducted individually for each locality as well as aggregated. The statistical analysis has shown, in comparative terms, the main influencing factors for carbon monoxide concentration variations according to traffic and physical local characteristics. There are some evidences from this research that environmental conditions, as a consequence of carbon monoxide concentrations caused by road traffic, are extremely poor in large Brazilian cities. (A)
Abstract