Traffic pollution in a downtown site of Buenos Aires City

It has recently been recognized that air and noise pollution constitutes an extended problem over the densely populated city of Buenos Aires. Traffic emissions are of paramount concern, especially along narrow and main traffi c arteries. In spite of these considerations, few systematic studies have b een undertaken to evaluate the air quality in the metropolitan area of the city. In 1996, concentrations of carbon monoxide (CO), nitric oxide (NO), n itrogen dioxide (NO2) and ozone (O-3) were simultaneously measured for the first time using a continuous monitoring station. This station was placed i n a building at Belgrano Avenue, which is a heavy traffic street in the dow ntown area of the city (Bogo et al., Atmospheric Environment 33 (1999) 2587 . In this work, we analyze the dependence of the measured primary pollutant s, CO and the mixture of nitrogen oxides (NOx), with meteorological conditi ons, traffic emissions and monitoring location. We compare the registered v alues with the results obtained from modeling the dispersion of the polluta nts emitted from mobile and area sources. We also discuss the relevance of street canyon effects compared with background concentrations of these poll utants. (C) 2001 Elsevier Science Ltd. All rights reserved.