Related Clues:

• Urban hazard
• Wintertime affliction
• Harsh cough
• Coarse cough
• Urban pollution
• Haze
• Cause of wheezing
• Industrial pollutant
• Visibility problem
• It's often caught in winter
• Air pollutant
• Big city haze
• It might hang over your head
• It might make you short of breath
• Infant's ailment