Characterization of PM2.5 during ACU15 campaign in Mexico City

Mexico City emits several thousands of tons of particle matter from transportation and other economic sectors. We collected PM2.5 samples from January to March 2015. The chemical analyses showed that PM2.5 is made up of 39% organic carbon, 12% elemental carbon, 23% metals (Al, Si, S, P, and K), and 5% heavy metals (Pb, Cr, Mn, Zn, and Hg). Ca and Fe were also present in trace concentrations, probably due to the resuspension of soils. Nitrate, sulfate, and ammonium suggest that the southwest of Mexico City, specifically the sampling site, receives more oxidated pollutants from vehicle emissions than other emissions. The chemical analyses show no significant changes in the composition or concentration of particle matter compared to previous studies.