The CDC is concerned about airports that still allow indoor smoking in designated public rooms.
A study by the federal health agency finds secondhand smoke levels directly outside public smoking areas were five times higher than the levels in smoke-free airports.
Those major airports with smoking areas are Hartsfield-Jackson Atlanta International, Washington Dulles International, McCarran International in Las Vegas, Denver International and Salt Lake City International.
An epidemiologist with the CDC says airport smoking areas and the areas around them are not healthy for workers or travelers, particularly children.
