The paper focuses on the potential health risks caused by the sub-10 micron fraction of volcanic ash (PM₁₀) following explosive eruptions of Mt. Etna (Italy). We present the results of a study on the ash concentration in the air of urbanized areas after the 15 November 2011 lava fountain and the related tephra fallout, causing high levels of PM₁₀ in the air. We conclude by hoping that due attention will be given to the impact of ash fallout on the Etnean territory in the future.