INCAS BULLETIN, Volume 4, Issue 4/ 2012, pp. 171 – 181 ISSN 2066 – 8201 Air quality assessment based on road traffic pollutants dispersion modelling: Giurgiu – Ruse Bridge Case study Victoria TELEABA* ,1 , Dragos MIHAI 2 *Corresponding author * ,1 COMOTI - National Research and Development Institute for Gas Turbines B-dul Iuliu Maniu 220D, Bucharest 061126, Romania victoria.teleaba@comoti.ro 2 COMOTI - National Research and Development Institute for Gas Turbines B-dul Iuliu Maniu 220D, Bucharest 061126, Romania dragos.mihai@comoti.ro Abstract: The paper presents a case study related to air quality assessment along an important high traffic bridge (Giurgiu - Ruse), by dispersion modelling of the main pollutants. In order to estimate the level of pollution caused by bridge road traffic in the closest urban areas, Giurgiu and Ruse and based on the traffic data, four scenarios for the air quality assessment have been carried out according to different meteorological conditions. The dispersion modeling was realized on specialized environmental pollution software, which features a fully operational Gauss model in its base module. There are presented dispersion maps for the main road traffic pollutants (NO x , CO, SO 2 , THC), aiming to evaluate their impact on the urban areas vicinity, in four different wind directions scenarios, at a constant temperature. Conclusions are presented according to available European Legislation and future scenarios are proposed, for other different meteorological conditions. Key Words: Air pollution, Dispersion maps, Modelling, Scenario, Road Traffic 1. INTRODUCTION Road Traffic, both for people and goods, is the most used mode of transport in present. Cars are a very convenient means of transportation with relatively low costs. But the true cost of using cars is very high if we consider the pollution and its environmental effects [1], [2]. Cars are a linear source of low altitude emissions of pollutants such as carbon dioxide, carbon monoxide, nitrogen oxides, sulfur oxides, particulate maters, lead, volatile organic compounds, all having a negative impact on the environment and on the human health [3], [4], [5], [6]. The traffic impact on human health is quantified through a higher incidence of cancer and heart diseases, more breathing issues/ and especially a continuous increase in the severity of diseases [7], [8]. Technological improvements that reduced emissions [9] were offset by a high traffic increasing, so that emissions are still growing. Emissions of pollutants from vehicles have two main features: first, elimination is very close to the ground, leading to the development of very high concentrations at ground level, even for lower density gases with large diffusion capacity in the atmosphere. Secondly, emissions are realized on the entire adjacent road surface, the concentration differences depending on the traffic intensity and the road ventilation possibilities [1]. The air pollution in urban areas due to the traffic from the inside of city or its vicinity is obviously influenced by specific geographical and urban factors and of course by weather conditions [10], [11]. DOI: 10.13111/2066-8201.2012.4.4.16