Particulate matter (PM10) air pollution is associated with respiratory and cardiovascular morbidity, and mortality. A recent systematic review pointed toward the fine particle fraction (PM2.5) rather than the coarse fraction (PM2.5-10) 2.5 and PM2.5-10as being responsible for increased death rates. With this background, the report by Perez et al that windblown Saharan desert dust causes increased mortality in Barcelona, raises concern over possible underestimation of toxicity from coarse particles coming from desert sources. This may be of concern for large areas of the globe that periodically encounter high levels of windblown desert dust and warrants further attention.