What else flies around in our air?

Did you recently noticed the color of the sun? I did, and immediately blamed the smog.  But no. It is actually the Sahara sand! (I did not realized it was orange while I was hiking in the country too.) This Scientist at the University of Nottingham even investigated it under scanning electron microscope.Well I was surprised if something like Sahara sand dust can travel continents, what else can travel waste distances if it's made of a fine particulate matter like the PM2.5 or PM10?

That's me!

You can imagine two regular neighbor states, with one having rigorous air protection regulation in place to keep harmful particles out of the air and the other state being just dirty as it gets. And the wind blows from the dirty one towards the clean one. How should the inhabitants of the clean state feel? A bit like powerless hostages. I could imagine that the political ties between the states could also suffer. I wonder if I could find such an example in the world. I already have an idea where to look.

Watch your neighbors, you may be not polluting, but how about them?