Related Clues:

• Scenery spoiler
• EPA concern *
• Its main ingredient is ozone
• Visible air pollution
• Fog polluted by smoke
• A mixture of smoke and fog
• Dirty mixture of smoke and fog
• Urban miasma
• Type of air pollution
• Subject of an exhaustive E.P.A. study?
• Urban bane
• EPA topic
• Houston problem
• Try writing about pollution
• Factor in an air quality rating