Size distribution of atmospheric particles during the Saharan dust episodes over central Europe in Spring 2021

Aeolian dust plays a major role in Earth’s climate, by absorbing and scattering radiation, and by influencing the hydrological and biogeochemical cycles. Saharan dust is a significant carrier of limited nutrients (e.g., iron and phosphorus) in many regions of the global ocean but also transfer toxic elements such as chromium, cadmium, arsenic, and lead, influencing public health and ecosystems. Annually, Europe receives millions of tons of Saharan dust while climate change is expected to increase the frequency and severity of dust episodes, especially in the south and central part, with unknown impact on sensitive ecosystems.  

During this study, aerosol particles were collected with a size-segregated hi-volume sampler (Tisch 230-High Volume Cascade Impactor). The impactor separated the particles in six different stages; from larger than 7.2 µm to less than 0.49 µm. Those samples were used to characterize the properties of dust particles during the severe dust episodes in Spring, 2021 in a forest site near Lausanne, Switzerland. We analyzed trace metals and nutrients (Fe, Cu, P, N), inorganic ions, sugars, and phospholipids. Preliminary results showed that a single dust episode can cause an increase of poisonous metals, such as lead and arsenic, by up to four times, affecting public health. In addition, it could be responsible for a large fraction of nutrients deposition - accounting for a significant part of the total annual deposition in the terrestrial and lake ecosystems in the area.