Related Clues:

• Haze
• Headache augmenter
• Industrial pollutant
• Visibility problem
• Air pollutant
• Cough cause
• Big city haze
• Discordance
• It might hang over your head
• It might make you short of breath
• Harsh sound
• White thing that may be heard?
• Los Angeles bane
• Urban pall
• It may be thick in Houston