Desert Dust Dispersion, Microbiology, and Impacts

The phenomenon known as ‘desert-dust storms' moves an estimated 2.2 x 109 metric tons of soil and dried sediment some distance in Earth's atmosphere each year. The largest of these frequent events are capable of dispersing significant quantities of dust and dust-associated microorganisms across oceans and continents. Major sources of dust are the Sahara and Sahel regions of North Africa and the Taklamakan and Gobi deserts of Asia. Dust transport out of these regions and to North America are frequently tracked and imaged by numerous remote sensing platforms. This presentation will present research conducted aboard two International Ocean Drilling Program (IODP) cruises (Expeditions 209 and 336), and atop Mount Bachelor (Bend, OR) to determine the types of culturable and non-culturable microorganisms that are detectable in atmospheric samples collected during dust events. Each research project has demonstrated that diverse communities of bacteria and fungi are present in the atmosphere when the research site is being impacted by desert dust at locations far removed from dust source regions. Recent research has demonstrated the presence of viruses in these types of samples. It is evident that pathogenic strains of microorganisms may present risk in impacted downwind environments through infection and the shuttling of intact and functional genetic packets.