- 1EPFL, ENAC, Environmental Engineering Institute IIE, Lausanne, Switzerland (kviolaki@gmail.com)
- 2Aix-Marseille Univ., Université de Toulon, CNRS, IRD, Mediterranean Institute of Oceanography (MIO), Marseille, France
- 3Central Environmental Laboratory, School of Architecture, Civil & Environmental Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, 1015, Switzerland
- 4Environmental Chemical Processes Laboratory (ECPL), Department of Chemistry, University of Crete, P.O.Box 2208, 70013, Heraklion, Greece
- 5Institute of Environmental Physics, University of Bremen, Bremen, Germany
- 6NILU - Dept. of Atmospheric & Climate Research PO Box 100, NO-2027 Kjeller, Norway
- 7Center of Studies on Air Quality and Climate Change (C-STACC), Institute of Chemical Engineering Sciences, Foundation for Research and Technology, Hellas, Patras, Greece
Lipidomics, a subfield of metabolomics, is an emerging field where hundreds to thousands of lipid species are simultaneously identified. Given the ubiquity and diverse biological roles of lipids, lipidomics offers valuable insights into mechanisms and the discovery of biomarkers related to environmental stressors that affect the cellular physiology and their numerous biochemical pathways. The major source of lipids in the atmosphere are the biogenic particles (bioaerosols) e.g., bacteria, fungi, pollen, plant fragments and viruses. Specifically, the terrestrial ecosystems including deserts, are the major sources of the atmospheric bioaerosols with urban environments and areas with agricultural and industrial activity being particularly important. The desert dust aerosols contain high concentrations of bioaerosols mainly composed of soil microorganisms and plant detritus. Agricultural dust can contain significantly more amounts of biological material, which subsequently can be enriched with additional biogenic particles when they are transported across terrestrial and aquatic environment through their coagulation with other airborne bioaerosols. The lipidome of airborne biogenic particles is unexplored to date, yet it can provide unique insights on bioaerosols, their stress state and oxidant exposure history. During this study we used lipidomics as a novel tool for the atmospheric research, to study the lipid changes in bioaerosols systems induced by their exposure to air pollutants and other atmospheric aging factors.
To achieve this, Saharan dust aerosols (n= 15) were sampled from East Mediterranean (Crete, Greece) using a high-volume (85 m3 h−1) TSPs sampler (TISCH). Dust atmospheric particles were collected on precombusted (450 °C for 5 h) 20 × 25 cm quartz filters (Pall, 2500QAT-UP). A reliable analytical protocol was established for lipidomics analysis of Saharan dust aerosols, which allowed us to identify approximately 60 lipid species, primarily phosphatidylcholines (PC), phosphatidylethanolamines (PE), triglycerides (TG), and their oxidation products, ceramides (Cer), and monogalactosyldiacylglycerols (MGDG). In addition to lipid analysis, biological identification and chemical analysis, including metals, major ions, and sugars, was also performed and will be discussed in detail.
Each dust event has a distinct signature, reflecting not only the chemical composition of the Saharan soil but also the atmospheric processing during its long-range transport. Preliminary results indicate a higher percentage contribution from the oxidation products of TG (OxTG, 33%) and PCs (OxPC, 22%) to the total identified lipids. The significant correlation between PCs and mannitol indicates a fungal contribution to airborne cholines. Furthermore, the correlation between anthropogenic metals (e.g., V, Ni, As, Cr, Pb) and galactolipids (MGDG), which are common plant membrane lipids, indicates a complex mixture of anthropogenic emissions and plant material in the dust aerosols due to long range transport of Saharan soil.
How to cite: Violaki, K., Panagiotopoulos, C., Rossi, P., Abboud, E., Kanakidou, M., Evangeliou, N., Groot Zwaaftink, C., and Nenes, A.: Lipidome of Saharan dust aerosols, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15888, https://doi.org/10.5194/egusphere-egu25-15888, 2025.