Análise e estimativa de inventários de emissões veiculares no estado do Rio Grande do Norte

Abstract

Air quality in a given region is defined by a combination of weather conditions and local emissions. The increasing number of air pollutants sources causes impacts on human health while also having an impact on climate and the environment. One way of assessing the flow characteristics of these pollutants is through the use of emission inventories, tools that quantify emission rates from various sources, to serve as a basis for the evaluation of atmospheric chemistry and for air quality management in a region. In Brazil many states need studies that characterize atmospheric composition, the Northeast Region mainly because of its fastly expanding urban areas and lack of studies on the subject. In this context, the objective of this study was a diagnosis of atmospheric emissions from vehicular sources in the state of Rio Grande do Norte (RN). Initially, for the first time, emissions generated by the global inventory Emission Database for Global Atmospheric Research (EDGAR) were evaluated for the state through the emissions module (EEM) of the atmospheric chemistry model European Air Pollution Dispersion (EURAD-IM). The adjustment of the EDGAR inventory was performed and the date were processed in the format necessary for the estimates, focusing on the road transport sector. Then, emission maps were generated for the region, identifying the main cities and the main vehicular traffic routes, in order to verify the accuracy of their spatial distribution, that is, to evaluate if the inventory represented the different emission source fluxes correctly. In addition, a Top-Down approach was performed with the VEIN vehicle emissions model, where sources could also be evaluated by vehicle type, fuel and fleet age. The largest pollutant was CO (23.789 t.yr - 1 ), followed by NOx (11.485 t.yr-1 ), HCNM (3.359 t.yr-1 ), PM (501 t.yr-1 ) and SOx ( 384 t.yr1 ). Light vehicles such as cars and motorcycles are mainly responsible for carbon monoxide (CO) emissions. These vehicles, which mostly consume gasoline or alcohol, are also responsible for more than 80% of HCNM emissions. While diesel-powered heavy-duty vehicles contribute to most of the emissions of particulate matter (PM), sulfur oxides (SOx) and nitrogen oxides (NOx). The results of these estimates have improved information for the region, as the VEIN emission maps have a much higher level of detail compared to the global inventory. With this work it was possible to obtain a better understanding of the pollutant emission fluxes and the spatial distribution, as well as the knowledge of the most relevant places and vehicle types in the sources contribution. Improvements have been made to vehicle emission data, generating a more realistic and higher resolution emission inventory for the region, which will contribute in the future to the study and management of air quality in RN and the NEB.