Elemental Analysis of Soils as Possible Resuspended Dust Sources in Mexico City

Soil samples were collected from seven sites in and around the Metropolitan Area of Mexico City. The locations were chosen as possible sources of fugitive dusts which contribute to suspended particulate matter in the atmosphere of Mexico City. X-ray Fluorescence (XRF) was used to determine the concentrations of several major elements (Si, K, Ca, Ti, Mn, and Fe), as well as of other trace elements that might be useful to identify the source of the airborne particles (Cr, Ni, Cu, Zn, Rb, Sr, Y, and Zr), while X-ray Diffraction (XRD) was employed to identify the most important mineral phases present in the samples. It was found that the concentrations of some elements and the presence of minerals (like albite, quartz, and calcite) show a certain similarity to those determined by other authors in samples of Total Suspended Particles (TSP) from this urban area. Also, a comparison is made with ratios of published elemental compositions of fugitive dust profiles for inhalable particulate matter (PM10 and PM2.5). The ratio Mn/Fe obtained in this work is very similar to all other studies, suggesting a crustal origin, while the ratios Cr/Fe and Ni/Fe in the other studies may be affected by anthropogenic sources.