Since the early 2000s, clusters of acute irritative and flu-like syndromes temporally associated with coastal exposure have been documented along Mediterranean shores, including Italy, France and Spain, and subsequently in other regions of the world [1–4]. These episodes, occurring during blooms of Ostreopsis species, suggest that benthic dinoflagellates could release cellular debris, palytoxin-like toxins, or other compounds into the air, exposing the population even without swimming. Similar outbreaks have since been described in other Mediterranean areas and in subtropical and Atlantic settings, including the eastern Adriatic, Brazil and the French Basque coast [5–8].
