It is now irrefutable that air pollution caused by large amounts of Total Suspended Particulates (TSP) and respiratory particulates or Particulate Matter less than 10 μm in aerodynamic diameter (PM 10 ) has numerous undesired consequences on human health. Air quality degradation far from the African continent, in the US and in Europe, caused by high concentrations of African dust, is seen as a major threat even though most of these countries are very distant from the Sahara. Surprisingly, no estimates of TSP or PM 10 levels near the Saharan dust source are available. Based on horizontal visibility observations which are reduced by the presence of dust in the atmosphere, TSP and PM 10 levels are estimated throughout the year 2000 at NouakchottAirport, Mauritania, using relations found in the literature. It appears that concentrations of particles are 10 . These very high particulate levels are likely to represent an important public health hazard and should be considered as a major environmental risk.