Related Clues:

• It may elicit a 6-Down
• What can take your breath away in L.A.?
• Urban pollution problem
• Industrial-zone feature
• Feature entertaining one row
• Photochemical phenomenon
• Static, e.g
• Dangerous blanket
• Bane for Beijing
• Obstacle to a city planner's vision?
• Unpleasant sound
• Industrially polluted air
• Rumour from informer first person's been arrested?
• Medic's warning finally accepted on sulphur pollution
• Row in northern French river