Characterisation of particulate matter and identification of emission sources in Greater Caracas, Venezuela

Between June and September 2018, particulate matter (PM) samples were taken in the Sartenejas Valley, southeast of Greater Caracas, Venezuela. The aim was to evaluate the morphology and the elemental chemical composition of particulate matter and establish possible emission sources during the rainy season. Functional groups were identified by FTIR spectroscopic analysis, and morphology and elemental composition were obtained by SEM-EDX analysis. The sampling period coincided with a Sahara dust storm. The SEM-EDX and FTIR analyses found evidence of mineral elements related to soil and crustal origins. The presence of C-rich or C-containing aerosols is related to biological sources or mineral carbon. SEM-EDX analysis of PM revealed the following particle groups: geogenic, metallic, C-rich, and secondary aerosols. Quantitative source appointments through principal component analysis (PCA) corroborated PM sources, including soil dust, sea salts, and reacted aerosols. According to the authors' knowledge, this study represents the first report to indicate that an episode of African dust could influence the particles collected in an intertropical continental sector in Venezuela, South America.

Automated summary

This study conducted in the Sartenejas Valley in Venezuela aimed to evaluate the morphology and elemental chemical composition of particulate matter, identifying different types of particles and confirming sources through principal component analysis (PCA), such as soil dust, sea salts, and reacted aerosols. Additionally, evidence of mineral elements related to soil and crustal origins was found through SEM-EDX and FTIR analysis during the rainy season, with the presence of C-rich or C-containing aerosols possibly linked to biological sources or mineral carbon.