Dr. Schmidt explains the world: silicosis caused by sand from the Sahara?

Over the Easter weekend, dust spread from the Sahara to Central Europe. How is that possible?

First of all, it is important to distinguish between the sand from the desert and the much finer dust particles. Because the finer the dust, the lighter it is. And what is light stays in the air longer. Especially in spring and autumn, there are strong air movements from Africa towards Europe. And they can then bring the Sahara dust with them. By the way: During volcanic eruptions, the dust sometimes stays in the air for a year or two, especially because it is thrown much higher into the atmosphere.

It’s amazing that the dust travels so many kilometers.

He doesn’t normally fly that far. We only got the last bit of it. The Mediterranean region generally gets more.

Can the amount be quantified?

For Switzerland alone, they estimated that around 180,000 tons of Saharan dust reached there at Easter.

That’s a decent amount. Is the dust dangerous? Keyword: silicosis.

The health risk for healthy people here is limited. Only asthmatics and other people with lung problems likely need to worry. On the other hand, the fine dust from the Sahara in these quantities poses an additional burden on the health of children in Africa. However, they live in areas where the fine dust pollution from open fireplaces is already quite high.

Is it also conceivable that sand dust particles from Germany arrive in the Sahara? From the Baltic or North Sea or the Verden dunes, for example?

I have never heard of the Baltic Sea sand moving all the way to the Sahara, or even its finest abrasion. The prevailing wind systems usually prevent this. There is no strong wind that blows from Central Europe towards North Africa.

Especially since the Alps are in the way, right?

The and further east the Carpathians. In Europe we have a relatively large number of mountains that go across the north-south direction of Winden.

What effects does desert dust have on flora and fauna?

Many wild plants on the Iberian Peninsula depend on dust. This is their natural fertilization. It’s even worse in the Amazon region: the rainforest there gets practically all of its phosphate supplies from the Sahara.

As is well known, the Atlantic Ocean lies between Africa and America. Isn’t that a hurdle for the dust?

No. The particles moving across the sea bring not only phosphate, but also a lot of iron. Iron is one of the nutrients for algae. Thanks to the iron from the desert, they can reproduce well. And when the algae die, they sink into the depths. If they sink fast enough, the CO contained in them is₂ tied to the seabed for long periods of time. Seen in this way, the dust winds also have an important function for the climate. That’s why there were already plans for ocean fertilization to produce more CO₂ to bind there. However, the idea did not catch on because of the uncertain side effects.