Département des sciences et gestion de l’environnement, Université de Liège, Avenue de Longwy 185, B-6700 Arlon Belgique
There is no longer any question that air pollution in the form of large quantities of total suspended particulates (TSP) and particulate matter less than 10 µm in aerodynamic diameter (PM
10) harms human health. Deterioration in air quality due to high concentrations of mineral dust from Africa affects the US and Europe, although most of these countries are far from the Sahara. Surprisingly, no estimates of TSP or PM
10 levels near the Saharan dust source are available. Measurements taken at Niamey-Airport in Niger of horizontal visibility, which is reduced by the presence of dust in the atmosphere, allowed us to estimate TSP and PM
10 levels according various relations found in the literature. Both the magnitude and frequency of mineral particle concentrations are very high. The average yearly concentration is estimated at 103 µg.m
-3 TSP and 67 µg.m
10. These very high particulate levels present a real public health threat to which national and international policy-makers must respond.