At this time of year in Europe, you may have noticed something in the air. Dust-laden winds blowing from the Sahara desert cause “seasonal haze episodes” that can even result in mud rain.
In West Africa, which experiences haze episodes between November and March, the dust-laden trade wind is called the Harmattan and has important implications, not only for soil fertility but also radio communication, visibility at airports and in shipping lanes, and also on livelihoods—and health.
Dry skin and cracked lips are regular symptoms of exposure to the haze. But it presents more serious problems for asthmatics—and can lead to silicosis, a lung disease caused due to a high content of quartz in the dust. In some areas the dust blocks the sunlight enough to make temperatures drop significantly.
And if the wind picks up…
Two regions have been identified as the sources of the Saharan dust: the Bodélé Depression in north-eastern Chad, which is part of the now dried up Lake Megachad—the most intense dust source in the world—and the Tibesti mountain region in northern Chad. Dust particles come from rocks in the Tibesti region and broken down by processes such as weathering, erosion and pulverization.
