Utilisation Des Tubes A Diffusion Passive Pour La Surveillance De La Pollution Automobile Dans La Ville De Meknes

Abstract

Road traffic emission is one of the major sources of air pollution which can cause several human health problems including cardiorespiratory diseases. The aim of our study is to monitor air quality in Meknes city (Morocco) by measuring nitrogen dioxide (NO2) and benzene (C6H6) concentration mainly generated by road traffic. To this end, we deployed passive diffusion tubes at 14 sampling sites during two measurement campaigns in the summer of 2014 and the winter of 2015 using car and underground proximity sites. In parallel with the winter measurement campaign, road traffic counting sessions were conducted on the main roads of the city in order to determine average daily traffic intensity. Results of this study show that the atmospheric concentrations of NO2 and C6H6 reach maximum values in the city center and decrease towards its periphery. The average value of NO2 in all targeted sites was around 32, 59 μg / m3, which is lower than the EU limit of 40 μg / m3. The average concentration of C6H6 in Meknes was equal to 1,77 μg / m3, a value close to the quality objective set by the European Union (2 μg / m3) and well below the annual Moroccan limit (10 μg / m3). The use of GIS (geographic information system) for coupling the results of measurement campaigns and those of traffic counting made it possible to determine the areas most affected by these tracers and thus to set up very high spatial resolution cartography.