Insights from the combined bulk chemical and surface characterization of airborne PM10 on source contributions and health risk: the case of three Mexican cities

The composition profiles of PM10 were investigated using microscopy and spectroscopy techniques. A 24-h intensive, wintertime measurement campaign was conducted to collect filter samples using high-volume instruments. The samples were analyzed by X-ray photoelectron spectroscopy (XPS), inductively coupled plasma mass spectrometry (ICP-MS), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), micro-Raman spectroscopy (MRS), and X-ray diffraction (XRD). The hazard quotient and incremental lifetime cancer risks were calculated to assess the health risks. The PM10 concentrations ranged from 29.80 to 78.86 μg/m3. Fe, Zn, and Cu were the most abundant elements with average contents of 737.8 ± 258.69, 164.33 ± 64.73, and 83.31± 68.65 ng/m3, respectively. The highly toxic elements As, Cr, and Pb were found at concentrations that suggest potential health risks. The XPS revealed C, O, and Si to be the major elements in the PM10 surface composition associated with aliphatic and aromatic hydrocarbons. The morphological analysis and PCA showed that the Fe-rich particles exhibited spheroidal morphologies, while the Pb-rich particles exhibited irregular and prismatic-type morphologies. These results suggest metal-work, lead-battery manufacturing, and the earth’s crust as emission sources. The cumulative risk of cancer suggests a moderate potential health risk that implies the need for preventive and corrective actions to improve air quality in urban cities. The combination of analytical techniques can be used to obtain better insights into the physical and chemical behavior of airborne particles in the atmosphere and potential tools to complement receptor models for source apportionment.