bacteria are deposited daily on every square meter around the planet. The presence of airborne cyanobacteria and microalgae as well as their negative impacts on human health have been documented by many researchers worldwide. However, studies on cyanobacteria and microalgae are few compared with those on other bacteria and viruses. Research is especially lacking on the presence and taxonomic composition of cyanobacteria and microalgae near economically important water bodies with much tourism. Research on airborne algae is especially important in tourist areas near water-bodies. Sunbathers are exposed to particularly high quantities of harmful cyanobacteria and microalgae. Additionally, harmful microalgae and cyanobacteria blooms tend to occur in both marine and freshwater reservoirs during summer. Previous work has shown that the Mediterranean Sea is dominated by the picocyanobacteria Synechococcus sp. and Synechocystis sp., which are responsible for the production of a group of hepatotoxins known as microcystins. Because most tourism occurs in summer, many tourists are exposed to the most extreme negative impacts of airborne microalgae. Airborne bacteria are emitted by most Earth surfaces (plants, oceans, land, and urban areas) to the atmosphere via a variety of mechanical processes such as aeolian soil erosion, sea spray production, or mechanical disturbances including anthropogenic activities. Due to their relatively small size (the median aerodynamic diameter of bacteria-containing particles is around 2–4 μm), these can then be transported upward by turbulent fluxes and carried by wind to long distances. As a consequence, bacteria are present in the air up to at least the lower stratosphere. Given that the atmosphere is a large conveyor belt that moves air over thousands of kilometers, microorganisms are disseminated globally. Airborne transport of microbes is therefore likely pervasive at the global scale, yet there have been only a limited number of studies that have looked at the spatial distribution of microbes across different geographical regions. One of the main difficulties is linked with the low microbial biomass associated with a high diversity existing in the atmosphere outdoor (~102–105 cells/m3) thus requiring reliable sampling procedures and controls. Furthermore, the site location and its environmental specificities have to be accounted for to some extent by considering chemical and meteorological variables. The environmental role of airborne cyanobacteria and microalgae is only partly understood. While present in the air, cyanobacteria and microalgae can contribute to ice nucleation and cloud droplet formation. Cyanobacteria and microalgae can also impact human health. Depending on their size, airborne