There are three approaches to having cleaner air:<p>1) Reduce the pollutants that get into the air (e.g. reduce factories)<p>2) Clean or redirect the polluted air in the sky<p>3) Clean the air in the small space you breathe (domestic air purifiers, or face masks)<p>(3) is the part individuals can control. (1) is very linked to GDP, and is mostly controlled by goverment policies.<p>Is anything possible in (2)? Is there a way to blow all the polluted air out of a city, with a huge fan or something?