Chemical composition of fugitive dust emitters in Mexico City

The gravimetric and chemical composition of fugitive dust emitters of Mexico City were analyzed to determine the particulate matter source profiles. Samples of geological material, unpaved and paved roads, agricultural soil, dried lake, asphalt, cement plants, landfill, gravel, and tezontle soil, were collected directly from the ground using a broom and a dustpan. These were dried, sieved and taken through a laboratory resuspension chamber to emulate the natural wind-blown processes of bulk soils and also to provide a uniform deposit on Teflon membrane and quartz fiber filters for further gravimetric and chemical analyses Of PM2.5 and PM10 size fractions. Chemical analyses of the filters included X-ray fluorescence for elemental composition, ion chromatography for water soluble anions, atomic absorption for water soluble metals, automated colorimetric analysis for ammonium and thermal/optical reflectance analysis for carbon species. The data show that most fugitive emitters are composed of 20-30% PM2.5, which is relatively less than the reported contribution by fossil fuels and biomass (40-60%). (C) 2001 Elsevier Science Ltd. All rights reserved.