Characterization of Non-Conventional Airborne Pollutants (BTEX) by means of Chemometric Techniques.

In this study, chemometric and spatial interpolation methods were employed to characterize non-conventional pollutants in the atmosphere of Santiago de Cali, Colombia. The pollutants were monitored using passive diffusion samplers during two distinct periods (January to February and March to April) in the two years after the pandemic (2021 and 2022). None of the monitored cases exceeded the concentration limits established by the National Air Quality Standard. Cluster analysis revealed distinct groups, categorizing sites into low, medium, and high pollutant influence. Principal Components Analysis (PCA) was employed to condense all variables into two primary constituents. The first component (PC1) serves as an indicator of mobile pollutant sources due to the consistent contribution of pollutants. Conversely, the second component (PC2) indicates punctual emissions of toluene, which made the most significant contribution. Spatial analysis demonstrated that downtown and the northern region of the city were highly influenced by PC1, with a substantial decrease in its effects towards the periphery, particularly the south. Utilizing Inverse Distance Weighting (IDW), we identified hotspots for both PCs, notably in areas undergoing real estate construction and the downtown industrial sector. Finally, our analysis revealed a cancer risk in the downtown and northeast areas of the city, associated with exposure to benzene and ethylbenzene. This observation aligns with the region of incidence indicated by PC1. [ABSTRACT FROM AUTHOR]