Related Clues:

• Cause of an air alert
• Unhealthy air
• It's hard to see through
• Urban problem
• Film
• Mist
• Metro-area haze
• Big city problem
• Befuddled state
• Eye irritant
• Smog, e.g.
• Sun block
• Harass, in a way
• Skyline hider
• 'Purple ___' (song played at Woodstock)