Saharan dust storms affecting the center of the Iberian Peninsula: effect on the urban aerobiome

Abstract

Dust storms are known to be atmospheric phenomena that transport mineral dust but also airborne biological particles (bioaerosols) from desert areas to distant regions. These bioaerosols can influence atmospheric processes and they have the potential of changing the composition of the local aerobiome in urban areas, which, in recent years, have been associated with allergies and the exacerbation of respiratory syndromes. Here, we studied four dust events initiated in the Sahara Desert affecting the center of the Iberian Peninsula. The biological particles before and during the phenomena were analyzed by high-throughput DNA sequencing. The global composition of bioaerosols showed a marked seasonality. The relative abundances of the most predominant groups of bacteria and fungi were not significantly altered compared to the days prior the corresponding event. Nonetheless, we detected specific bacterial and fungal taxa associated with these events, whose composition and abundance were also related to the period of the year. Although a variety of plant and animal pathogens were identified both before and throughout the days influenced by dust storms, some were only detected during the latter, suggesting a long-range transport for these species. This work highlights the importance of analyzing the storm dust events separately, especially when they occur at different seasons, and the particular effect on an urban environment in the Iberian Peninsula as a model case, providing some recommendations for future studies.