What creates so much pollution in Africa?
What you can see in your image is mostly dust from the shara desert https://earth.nullschool.net/#current/particulates/surface/level/overlay=pm10/orthographic=13.33,5.70,766 

You will be able to see other types of particles like smoke from combustion like cars-industry-forrest fires,the picture show particles that is 10 microns in size.

On the linked page you can find details of other types of chemical and particulate emissions too like SO2 and CO2 it is a good source for information about the atmosphere.