http://www.cbsnews.com/news/google-tracks-air-pollution-when-mapping-streets/ "In Oakland, California, the Google cars that collect maps and photographs of city streets have also been collecting air, and measuring pollution block by city block." I saw this on the news just now. Google is collecting tons of stuff, why not hot air? Think this will be useful/accurate/globally feasible/on the level? A couple of the comments that follow are golden.
Might be helpful (if also equipped for it) Carbon Monoxide and/or other toxic fumes in abundance. Sort of a HazMat Monitor on wheels.