Diagnóstico das emissões atmosféricas em Minas Gerais: um estudo para as fontes fixas e veiculares

Abstract

Urban areas are particularly complex environments, characterized by the presence of various pollutants emitted by multiple sources. A number of different spatial and temporal scales are involved in the processes of chemical transformation and transport of these pollutants into the atmosphere. The definition of strategies and policies to mitigate the adverse effects of exposure to air pollutants requires full knowledge of their characteristics and dynamics in urban environments. Atmospheric emission inventory is an essential tool for these assessments. In Brazil, the state of Minas Gerais, as well as its capital, Belo Horizonte, are in this context. In these areas, there are a lack in studies with focus on the atmospheric pollution diagnosis, especially in relation to sources identification, emissions quantification and evaluation of environmental dispersion and contamination processes. In this sense, the general objective of this study was to diagnose the atmospheric emissions by stationary and vehicular sources in Minas Gerais. For this, in a first step, the atmospheric emissions by vehicular sources were quantified throughout the state, following the national methodologies, proposed by the Ministry of Environment and CETESB (Companhia Ambiental do Estado de São Paulo). In a second stage, the stationary emission sources in its capital, Belo Horizonte, were identified and quantified, based on monitored data, as well as estimates using emission factors following the AP-42 guidelines (Compilation of Air Pollutant Emission Factors from United States Environmental Protection Agency). For vehicle emissions, it was observed that, in Minas Gerais, among the oxide gases, NOX was the most emitted, followed by CO and SO2, with emission rates of 117,708, 103,295 and 4,760 t.year-1, respectively. In relation to vehicular VOC and PM, total emission rates of 26,181 and 8,957 t.year-1, respectively, were observed. For stationary sources in Belo Horizonte, 75 chimneys were identified, distributed in 28 companies. In relation to the pollutants emission by these chimneys, rates of 305, 235, 234, 180 and 63 t.year-1 were observed for NOX, CO, MP, SO2 and VOC, respectively. The results obtained in the present study can contribute to the diagnosis, modelling and management of air quality in Minas Gerais