Related Clues:

• Environmental problem
• Sun blocker
• Serenity spoiler
• Bing, bang or boom
• Unwelcome cloud
• Polluted air
• Hush breaker
• Some factories contribute to it
• Disturbance
• Big city bane
• Click or clack
• Headache intensifier
• Library no-no
• Environmental concern
• Static, e.g.