Variations Saisonnières des particules atmosphériques et ses composants chimiques dans la Ville de Meknès – Maroc (Seasonal variations of the atmospheric particles and its chemical components inMeknes city-Morocco)

This work is a study of the particulate and elementary matter in the town of Meknes in Morocco. The aerosol samples were collected with Gent PM-10 stacked filter unit (SFU). The aerosol particles were separated by the SFU into a coarse and a fine sized fractions. The pollutants were collected between March 2007 and April 2008. The chemical concentrations of thirteen elements (Ca, Cl, Cr, Cu, Fe, K, Mn, Ni, Pb, S, Sr, Ti and Zn) weredetermined by X-ay Fluorescence with Total Reflexion (XFTR), whereas Al was is determined by the Atomic Absorption Spectrometry. In the case of the matter particulate, the fine/PM-10 ratios are in general rather weak (lower than 0.5), showing the importance of the terrigenous contributions and the handing-over in suspension of the ground, especially in July and August when the coarse fraction reaches the highest contents (increase in the wind erosion of the ground). The concentrations measured were found to be higher than European quality standards and recommendations of World Health Organization air quality (WHO), while the chemical composition does not present a great difference between the fine and coarse fractions with a mass percentage of 19 to 23% of the total mass of the particles. Moreover, the seasonal variation is less important. It is also noted that the Ni and Pb contents are higher than the air quality standards. Moreover, the comparison with former works show a great similarity between several works released in Africa and even in Europe. However, the best quality of the air is that recorded in France