Winds from the SaharaÐSahel region of Africa transport large amounts of dust across North Africa and the Mediterranean to Southern Europe, increasing ambient air dust concentrations that may last several days. Saharan dust clouds may have important implications for health. A study conducted in Barcelona, Spain found that during Saharan dust intrusions the effect of the coarse fraction of the particulate matter increased daily mortality. In the Sahel region of Africa the coincidence of meningitis epidemics and seasonal upsurges in endemic disease with dry dusty conditions has prompted the suggestion that these are also associated.