Application of nuclear analytical techniques (XRF and NAA) to the evaluation of air quality in moroccan cities. Case of Meknes city
Résumé
Meknes City is located in northern of central Morocco at the medium Atlas and it contains about 171 industrial units. The studied site is characterized by important road traffic and it is situated in the center of Meknes city, near a taxis station and not far from railway traffic. The sampling was carried out from March 2007 to November 2008. During this period, particulate matters (Fine and Coarse) were collected using, Gent, Partisol and Dichotomous samplers. The collected filter samples were analyzed using Total Reflection X-Ray Fluorescence and Neutron Activation Analysis. Besides, the sources of emissions of fine and coarse fractions were identified by means of enrichment factor analysis. The distribution of element contents between fine and coarse fractions showed that most of the analyzed elements are equally distributed on both fractions; except for some elements like Ca that was more distributed in coarse fractions and Ni that was more concentrated in fine fractions. These results were supported by the calculation of the ratios (Fine/Coarse) of each element for the four seasons. Enrichment factor analysis revealed that Fe and K came mainly from natural sources; Ca, Mn and Ni came mainly from natural sources but we cannot rule out the possibility of contamination from anthropogenic sources; Cr, Cu, Zn and Pb were attributed mainly to anthropogenic sources. The Principal Component Analysis identified crustal, traffic and industries as emission sources for coarse and fine particles.