As traffic and other sources add more pollutants to the air, the smog gets worse. Ironically, smog is often more severe farther away from the sources of pollution, because the chemical reactions that cause smog take place in the atmosphere while pollutants are drifting on the wind. Smog: Frequently Asked Questions.
There are two major airports if you are flying into the Big Island, Kona International Airport [1] and Hilo International Airport [2]. There are a few non-stop flights from the mainland, mostly from California and Seattle, but it is more common to arrive via Honolulu or Kahului.
Iowa is a fairly large state with 122 airports. The Airports in Iowa are well connected to the other states in the US. The only international airport in Iowa is the Des Moines International Airport, which receives almost two million passengers annually. The airport is technologically up to date which makes flying as easy as is possible for the passengers regardless of the weather changes.