To the Editors: The dramatic volcanic eruption in Iceland has recently brought the possible health effects of volcanic ashes to the general attention of the media. Lessons learnt from other episodes may be of interest and could guide future public health action. During Autumn 2002, a large eruption of Mount Etna (Sicily, Italy) occurred. It persisted for 3 months, showing peaks of intense volcanic activity characterised by explosions, jets hundreds of metres high and seismic activity. Local winds carried the ash columns for kilometres, causing discomfort to the population of Catania (nearly 370,000 inhabitants) and other inhabited areas near the volcano. Repeated episodes of rainfall occurred after the eruption, reducing the phenomenon of ash resuspension. The population was alerted by a general alarm caused by national and local mass media. National and local authorities enacted measures aimed at preventing health effects: schools were closed; motor vehicle circulation was prohibited; protective eye masks were distributed; the elderly and individuals affected by chronic diseases of the respiratory system were suggested to limit their outdoor exposure and to reduce physical activity. An epidemiologic study 1 on acute health effects on the nearby population was conducted. During the study period (106 days of observation in 2002; 59 days of eruption and 47 days of …