It is not just sand and dust. Dubai burns immense amounts of gas to produce it's electricity and water plus in the aluminium smelter next door to the main power plants in Jebel Ali. The amounts of CO2 emitted are mind boggling. Plus a good deal of sulphur and sulphurous products are spewed out. If we had any rain here it would be very, very acidic.
Not to be outdone, Abu Dhabi also built a huge smelter.
I'm not sure where the small particulates come from - in places like Oxford St., UK, diesel vehicles are commonly blamed. Our trucks here are certainly not well maintained but are there enough of them to cause a problem?
Tehran has terribly visible air pollution in the winter time - trapped by temperature inversions. That is mainly caused by traffic - since on a 2/3 day holiday even in still weather conditions it vanishes. Photochemical smog caused by the actions of sunlight at high altitude (the city is about 1200m up) reacting with dirty exhaust products. Same as in Mexico City.
UAE doesn't have the altitude but we have plenty of sunlight - could this be a contributory factor?
Wherever it comes from, and whatever causes it, air pollution in UAE is a serious problem. And it won't get any better soon. DEWA are in the process of awarding contracts for the next major power station. Coal-fired this time. Just to add to the mix of muck in the air.