Emissões de poluentes atmosféricos do sistema de transportes: inventários e predições

Abstract

Greenhouse gas emissions and air pollutants have been increasing currently in the face of human activities. The way of life based on comfort and consumption requires the adoption of the intensive use of fossil fuels. The transport sector is the main emitter, especially since a fleet of vehicles has grown at an accelerated pace in the last decades. These emissions are an important part of climate change and air pollution, which boosts global warming and reduces the health and well-being of the population. In this way, it is important to monitor the quality of urban air in order to avoid episodes that compromise human life. For all this, it is salutary to observe levels of tropospheric ozone and particulate matter, among other pollutants, in order to prevent degradation public health events and promote environmental management. Brazilian legislation guides the creation and implementation of State programs for air quality, with the purpose of controlling emissions to acceptable limits. However, the use of mathematical models of prediction instrumentalism as part of these programs. As an initial condition, to feed them, it is necessary to make available a set of meteorological variables, but also the concentrations of pollutants gases from fixed and mobile sources. In this work, we tried to analyze the impacts caused in the urban air from the emissions of the transport sector, only. For this purpose, it was essential to estimate the emissions of greenhouse and local gases from the city of Manaus, defining as the frontier of the inventory the sale of fuel in the urban perimeter. These estimates establish in protocols guided by the IPCC, but also in the recommendations of the Brazilian Government and in the experiences of other large urban centers. Then the space-time dispersion of pollutants resulting from emissions was simulated, so that it could be understood its behavior and distribution. However, in order to analyze an intervention scenario, it was also simulated the scenario of improvements proposed in the Urban Mobility Plan of Manaus, whose proposal suggests changes in the road system and in the public transportation system. The model used was the TAPM (The Air Pollution Model) because it is three-dimensional and suitable for modeling meso-regional scales and coherent to cover the studied area. Carbon dioxide emissions have increased substantially, although emissions of methane, non-methane hydrocarbons, nitrogen dioxide, aldehydes, carbon monoxide and particulate matter have declined substantially due mainly to the implementation of more advanced phases of Program for the Control of Air Pollution by Automotive Vehicles (PROCONVE) and Program for the Control of Air Pollution by Motorcycles and Similar Vehicles (PROMOT), but also the mixture of anhydrous ethanol in pure gasoline. The simulation of the impacts on air quality showed that the dispersion of all pollutants, with the exception of the particulate matter, follows the expected surface runoff and goes towards the west and the Negro river. However, only the ozone, in two distinct moments, exceeded the legal line established by CONAMA. For the improvement scenario, the results point to an improvement in air quality levels for all simulated pollutants.