Air Pollution export from a city to its neighbouring areas

MAZZEO, N.A.; PINEDA ROJAS, A.L.; VENEGAS, L.E.

Cambridge, UK

Conferencia; 11th International Conference on Harmonisation within Atmospheric Dispersion Modelling for Regulatory Purposes; 2007

Cambridge Environmental Research Consultants

The development of a methodology to estimate the transport of air pollutants emitted in an urban area, across city borders towards neighbouring areas is presented. The proposed methodology includes analytical expressions that have been developed using equations of an urban atmospheric dispersion model. As an application of this method, the transport of CO across the borders of the city of Buenos Aires is evaluated. Annual emission of CO in the city is 240000ton. The mass of CO emitted in the city that is transported to seven districts (which limit with the city) of the Greater Buenos Aires and to the de la Plata River is estimated. The largest rate of CO (77700ton/year) is transported towards the de la Plata River, on the east side of the city, and the smallest (18300ton/year) towards the district of Avellaneda, located south of the city. The main factors (wind direction, wind speed, length of the limit between the city and each neighbouring district, air pollutant concentration at the border, annual number of hours with effective flux across the border) that condition the outflow flux of CO through the city boundary are evaluated and their relative importance is analysed. Also the impact of carbon monoxide (CO) emitted in Buenos Aires city on its neighbouring areas is estimated. Ground-level CO air concentrations in the Greater Buenos Aires originated by the emissions from sources located in the city are calculated. Greater impact of the CO emitted in Buenos Aires appears in the zones of the Greater Buenos Aires located west and northwest of the city. The most affected areas are located in the districts of Tres de Febrero (4.5km2 – 35200inhab.) and Vicente López (0.8km2 – 7600inhab.), where, during more than 20 times/year, the emissions from the city are responsible for situations of 8h CO ground-level concentrations greater than 3mg/m3. This value represents 30% of the air quality standard for the Greater Buenos Aires (10mg/m3).