To see smog (pollution) in your dream, indicates your negative emotions. You may be feeling upset and fearful of a situation or relationship. Alternatively, it suggests that you have not clearly understood a situation well enough to make an informed decision.
In a moral fog created by oneself.
Dreams of smog signify overwhelm, negativity, mental clutter and/or a smokescreen to mask what is really going on in your life. This dream may be giving you the message that you are in need of an emotional rainstorm, a good cry to cleanse the pollution of your mind and heart.