From multi to single-particle analysis: A seasonal spectroscopic study of airborne particulate matter in Zaragoza, Spain

It is distinguished that deficient outdoor air quality is responsible for substantial health and climate issues. The aim of our study was to investigate the air quality in the city of Zaragoza (Spain) by characterizing atmospheric particulate matter (PM) during two seasons (winter and spring). PM samples were collected in 2022 in quartz filters through a low-volume sampler and chemically analysed by complementary analytical techniques: Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), Laser Induced Breakdown Spectroscopy (LIBS), Raman Spectroscopy (RS) and Field Emission Scanning Electron Microscopy with Energy-Dispersive X-ray Spectroscopy (FESEM-EDS). Results have revealed, together with a temperature inversion phenomenon in winter, the presence of both natural (Al, Ca, Mg, Ti, Sr, Fe, etc.) and anthropogenic particles. The latter mainly formed by black carbon with an origin on fossil fuel combustion emissions. Additionally, chemical analyses of PM filters showed the presence of three types of microplastics suspended in the air of the city: polyethylene terephthalate (PET), polyamides (PA) and polystyrene (PS). The results obtained from this research are of special interest to take into account for future air quality policies, particularly those with the aim of reducing air pollution in cities.