\" \" The beautiful downtown area of Honolulu, Hawaii, has the best air quality of all cities in the world of similar size. Ozone pollution comes from gases like exhaust from tailpipes and smoke from factory chimneys. Particle pollution is mostly created by car and truck traffic, manufacturing, power plants and farming. Here are the top five major cities with the cleanest air in the world:Honolulu, HawaiiHalifax, CanadaAnchorage, AlaskaAuckland, New ZealandBrisbane, AustraliaWherever in the world they're located, the cleanest cities tend to have certain things in common. Now That's Interesting China's air pollution is so bad you can see it from space.