This research investigated the current methods of characterization of ions and metals in particulate matter pollutants from different emission sources. The study was conducted through the Proknow-C methodology, in which a portfolio that includes scientific and review articles was selected. The document addresses different methodologies currently used to quantify diverse ions and metals (IIMM) found in particulate matter (PM), specifically focused on PM₁₀ and PM_2.5. The investigation was made going through the types of filters used to capture the pollutant, the equipment and the corresponding characterization techniques. Results show the Proknow-C method is a reliable way to analyze PM pollution research, revealing the state of art for metals and ions types, characterization technologies, current situations and trends. Sulfate, nitrate, and ammonium ions are found in concentrations between 70 and 80% of the PM. Among the main metals found are chromium, nickel, lead, cadmium, iron, manganese, coper, and zinc. The main detection method found in the studied research was inductively coupled plasma mass spectrometry. It was also found that geographic information systems are a good tool for integrating special data with PM and air pollution, which could accelerate the diagnosis and thus the actions to give solution to the problem.

Medellín, a densely populated city in the Colombian Andes, faces significant health and environmental risks due to poor air quality. This is linked to the atmospheric dynamics of the valley in which it is located (Aburrá Valley). The region is characterized by a narrow valley and one of the most polluted areas in South America. This is a comparative study of the chemical composition of PM_2.5 (particles with diameter less than 2.5 µm) in Medellín between two periods (2014–2015 and 2018–2019) in which temporal trends and emission sources were evaluated. PM_2.5 samples were collected from urban, suburban, and rural stations following standardized protocols and compositional analyses of metals (ICP-MS), ions (ion chromatography), and carbonaceous species (organic carbon (OC) and elemental carbon (EC) by thermo-optical methods) were performed. The results show a reduction in average PM_2.5 concentrations for the two periods (from 26.74 µg/m³ to 20.10 µg/m³ in urban areas), although levels are still above WHO guidelines. Urban stations showed higher PM_2.5 levels, with predominance of carbonaceous aerosols (Total Carbon—TC = OC + EC = 35–50% of PM_2.5 mass) and secondary ions (sulfate > nitrate, 13–14% of PM_2.5 mass). Rural areas showed lower PM_2.5 concentrations but elevated OC/EC ratios, suggesting the influence of biomass burning as a major emission source. Metals were found to occupy fractions of less than 10% of the PM_2.5 mass; however, they included important toxic species associated with respiratory and cardiovascular risks. This study highlights progress in reducing PM_2.5 levels in the region, which has been impacted by local policies but emphasizes current and future challenges related mainly to secondary aerosol formation and carbonaceous aerosol emissions.

This study assessed the chemical characterization of PM _2.5 at an urban background site in Medellín—Colombia, a city situated in a topographically constrained valley exposed to air pollution accumulation influenced by its complex Andean topography and a combination of local and regional emission sources. A total of 112 samples of PM _2.5 were collected between March 2019 and March 2020, samples went through comprehensive sampling and chemical characterization (ICP-MS for metals, ion chromatography for anions, thermal/optical analysis for carbonaceous species). Daily PM _2.5 concentrations ranged from 8.15 to 37.86 μ g/m ³ (mean: 21.73 ± 6.75 μ g/m ³ ). Principal Component Analysis (PCA) identified five major pollution sources, with mineral and resuspended dust (33.6% of explained variance) and secondary aerosols (17.0%) being the most prominent. The study area experiences clearly defined dry and wet periods, marked by distinct precipitation regimes. During the year these atmospheric conditions influence the concentration levels of pollutants. The integration of NOAA HYSPLIT back-trajectories and NASA FIRMS (VIIRS J2) fire hotspot data revealed long-range transport from the Magdalena, Orinoco and Amazon basins, deteriorating local air quality specially during dry periods. While local traffic and industrial emissions constitute a constant baseline, regional biomass burning and unfavorable meteorological conditions are the primary drivers of episodic high-pollution events. The study underscores the need for targeted strategies addressing both persistent sources as traffic or industrial emissions and episodic events to mitigate health and environmental impacts.